Study Questions/Answers and Explanations (Cardiology)

Study Questions/Answers and Explanations
A 52-year-old man presents with fever, chills, and arthralgia. On physical examination: temperature is 102.2آ°F, pulse is 106 bpm, blood pressure is 100/60 mm Hg, respiratory rate is 22. S1 is soft. There is a short II/VI diastolic blowing murmur at the left sternal border. There are no rashes or petechiae. The results of the rest of the examination are unremarkable.
1. What is the most likely diagnosis?
A Viral syndrome with flow murmur
B Acute systemic lupus erythematosus with aortic valve involvement
C Infective endocarditis of the aortic valve with probably mild insufficiency
D Infective endocarditis of the mitral valve
E Infective endocarditis of the aortic valve with probably severe insufficiency
View Answer

1. The answer is E [IV C 3 b (2)]. The diastolic murmur is typical of that of aortic insufficiency. The fever chills and arthralgia suggest infection, making infective endocarditis the most likely diagnosis. The soft S1 suggests mitral valve preclosure, indicating severe disease. This syndrome could be seen in acute lupus, but this is less likely in a man without other evidence of the disease. Increased flow from any cause does not produce aortic insufficiency. A lesion on the mitral valve creates systolic, not diastolic, murmurs.
2. Which of the following statements is true of the condition of the patient in question 1?
A The cardiac physical examination is hyperdynamic.
B S1 is soft because of aortic valve preclosure.
C Mitral valve preclosure indicates a poor prognosis without aortic valve replacement.
D The appearance of a diastolic murmur is usually benign.
E Hill's sign is a good predictor of severity.
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2. The answer is C [IV C 3 b]. Mitral valve preclosure, caused by high ventricular diastolic filling pressure, greater than left atrial pressure, indicates severe disease that is usually fatal without aortic valve replacement. In acute aortic insufficiency such as that seen in endocarditis, Left ventricular dilation has not yet occurred, stroke volume is not increased very much, and thus the circulation is not hyperdynamic. Therefore Hill's sign is also absent. In general, diastolic murmurs are not benign and indicate valve pathology.
3. The diagnostic test(s) that should be performed next is/are
A A chest x-ray
B Blood cultures
C Cardiac catheterization
D A radionuclide ventriculogram
E Exploratory thoracotomy
View Answer

3. The answer is B [IV C 4]. Blood cultures to confirm a bloodstream infection and echocardiography to identify valve lesions and valve function are the mainstays of diagnosis in infective endocarditis. Although a chest x-ray might be useful, it is never diagnostic of endocarditis. Valve surgery would not be contemplated without the diagnosis of endocarditis being established first. Cardiac catheterization is rarely indicated in endocarditis today because echocardiography provides more information more safely. A radionuclide ventriculogram would give information about cardiac performance but would not confirm the diagnosis.
A 56-year-old man enters the emergency department complaining of dyspnea that began about 3 weeks ago and has progressed so that he now has difficulty walking across a room. He has begun sleeping on three pillows. On physical examination: temperature is 99(F, pulse 102 bpm, BP 130/90 mm Hg, respiratory rate 24. There is jugular venous distention, and estimated central venous pressure is 10 cm H2O. Other findings include bibasilar rales and an S3 gallop.
4. What is the most likely diagnosis in this patient?
A Pulmonary embolism
B Congestive heart failure
C Emphysema
D Pneumonia
E Atrial septal defect
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4. The answer is B [I D 1–2]. The gradual onset of dyspnea, the pulmonary rales, and the S3 gallop are all typical of congestive heart failure. Although a pulmonary embolus could cause all of the findings in this patient, even a right-sided S3, sudden onset is the norm in that condition. The other conditions all could cause dyspnea but would not cause gallop rhythm.
5. Which of the following tests is most appropriate to aid in establishing therapy for this patient?
A A chest x-ray
B An echocardiogram
C An electrocardiogram
D A heart catheterization
E A radionuclide ventriculogram
View Answer

5. The answer is B [I E (3)]. An echocardiogram will yield data about systolic and diastolic function, chamber size, and valvular abnormalities. All of the other tests are useful, but all except catheterization give less information than the echocardiogram. Cardiac catheterization has a higher risk and is only employed when the information gained outweighs that risk. Thus, in CHF, echocardiography provides the “biggest bang for the buck.â€‌
6. Which of the following is true about the treatment of the condition of the patient in question 4?
A The cause of the condition should be treated whenever possible.
B Systolic versus diastolic dysfunction usually cannot be established.
C ACE inhibitors improve symptoms but do not prolong life.
D Diuretics are the court of last resort.
E خ²-blockers are dangerous and should be avoided.
View Answer

6. The answer is A [I F (1)]. Congestive heart failure is a syndrome, and its cause should be sought and treated directly whenever possible. It is usually helpful to establish whether the root cause is systolic or diastolic dysfunction, a distinction made easily with echocardiography. Diuretics form the mainstay of therapy, but adding both ACE inhibitors and خ²-blockers prolongs life.
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On a routine office visit, a 45-year-old man complains that recently he has noted right-sided chest pain while mowing his lawn with a push lawn mower. The pain develops suddenly, lasts 2–3 minutes, and subsides when he rests. He denies smoking or a history of hypertension, diabetes, or hyperlipidemia. His physical examination is unremarkable. An ECG shows nonspecific T-wave abnormalities.
7. This patient most likely has which of the following?
A Angina pectoris
B Hiatal hernia
C Pleuritis
D A nonspecific chest pain syndrome
E There is not enough information to arrive at a diagnosis.
View Answer

7. The answer is E [III A 5 a (1)]. His presentation with exertional pain is typical of angina, but the location, duration, and lack of risk factors are atypical. No diagnosis can be made based on this information.
8. What should be the next step in establishing the diagnosis for this patient?
A Repeat the ECG
B Perform a cardiac catheterization
C Obtain cardiac enzymes and a troponin level
D Perform a stress ECG
E Perform a stress echocardiogram
View Answer

8. The answer is E [III A 5 a (3)]. A stress echocardiogram will give information about cardiac function and the presence of coronary disease (90% sensitivity). Repeating the ECG is unlikely to give new information. The brevity of the pain makes it very unlikely that myocardial damage has occurred, and thus troponin is likely to be normal. The stress ECG will be of limited use because the resting ECG is already abnormal. Cardiac catheterization could be employed, but because of its invasive nature it is usually not the first step in arriving at a diagnosis.
9. If coronary disease is found in this patient, indications for surgical revascularization would include which of the following?
A Occasional angina
B Left main coronary stenosis of 20%
C Three-vessel coronary artery disease with left ventricular systolic dysfunction
D Disease of the right and circumflex arteries
E A severe lesion in one coronary artery
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9. The answer is C [III A 5 a (4) (e)]. Surgical revascularization has shown a mortality benefit for patients with disease of >70% of all three epicardial coronary arteries and associated left ventricular dysfunction. In addition, a mortality benefit has been shown for patients with >50% stenosis of the left main coronary artery, irrespective of ventricular function. Given the risks of surgical revascularization, medical therapy and/or percutaneous intervention should be considered first for patients who are not likely to experience a mortality benefit from bypass surgery.
A 56-year-old man with a history of hypertension is seen for the evaluation of chest pain that began an hour ago. The pain was centered in the left side of the chest and radiates to the left arm. It was associated with nausea and vomiting. His physical examination findings are:
Blood pressure 80/60 mm Hg, pulse 58 bpm, and respiratory rate 16
Chest: clear
Heart: no gallops or murmurs
ECG: Acute anterior myocardial infarction and sinus bradycardia
10. What should be the next step in management of this patient?
A Insertion of a temporary pacemaker
B Administration of nitrates
C Fluid resuscitation
D Insertion of an intra-aortic balloon pump
E Administration of a خ²-blocker
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10. The answer is C [III A 5 b (4)]. The patient is hypotensive, as he has no signs of volume overload or heart failure; thus, fluid resuscitation should be performed first. Although both خ²-blockers and nitrates are indicated in MI, their use here would only exacerbate the hypotension. A pacemaker might improve blood pressure but only if AV sequential pacing were used, a sometimes complex procedure. In fact, pacemakers are rarely used for mild sinus bradycardia. Intra-aortic balloon pumping would be used only if other measures failed to restore blood pressure.
11. After the patient in question 10 is stabilized, he should:
A Be transferred to the critical care unit
B Undergo immediate percutaneous coronary angioplasty if available
C Receive warfarin
D Receive nifedipine
E Receive intravenous lidocaine
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11. The answer is B [III A 5 b (4) (b)]. If acute angioplasty is available, it should be performed immediately to restore coronary blood flow without transferring the patient to the coronary care unit (CCU), because every minute counts in preserving myocardium. Dihydropyridine calcium channel blockers such as nifedipine are contraindicated in MI because they increase mortality. Lidocaine is no longer used prophylactically against cardiac arrhythmias because of possible cardiac standstill. Although heparin is an essential part of therapy, warfarin, which takes days to become effective, is not.
12. On the second hospital day, the patient becomes diaphoretic and hypotensive. A III/VI holosystolic murmur is heard. Which of the following is likely?
A He has developed pericardial tamponade.
B There has been acute ventricular septal rupture.
C He has an acute atrial septal defect.
D He has developed mitral valve endocarditis.
E The murmur was old but obscured by the reduced cardiac output from his MI.
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12. The answer is B [III A 5 b (6) (e)]. Hemodynamic decompensation and a new cardiac murmur after MI indicate either acute ventricular septal rupture or acute mitral valve dysfunction. Atrial septal defect is not a consequence of MI. There is no indication that the patient has developed endocarditis. If anything, the patient's output has been still further reduced, as indicated by his change in vital signs. There are no signs of tamponade, such as pulsus paradoxus or neck vein distention.
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13. Ultimately this patient's prognosis will be determined most by which of the following?
A The amount of myocardial damage he has sustained.
B His LDL cholesterol level
C His HDL cholesterol level
D The ratio of LDL to HDL cholesterol
E Blood pressure control
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13. The answer is A [III A 5 b (5) (a)]. Prognosis is dependent most on the amount of muscle damage (and therefore the amount the ventricular dysfunction that develops), the patient's age, and the extent of coronary disease. Although improving the status of known coronary risk factors such as hyperlipidemia and hypertension reduces subsequent risk, the effect on prognosis is not as large as are muscle damage, age, and extent of disease.
A 25-year-old woman presents with chest pain that worsens when she inspires. Her physical examination findings are blood pressure of 120/70 mm Hg, pulse 76 bpm, respiratory rate 14, Heart: three-component friction rub.
14. Which of the following statements is true of the friction rub?
A It is generated by movement of the parietal and visceral layers of the pericardium.
B It is generated by the visceral layers of the pericardium and pleura.
C It indicates the absence of an effusion.
D It indicates that the cause of the pericarditis is a malignancy.
E It often persists through effective therapy.
View Answer

14. The answer is A [VI A 2 b]. The rub is caused by movement of the inflamed parietal and visceral layers of the pericardium. A rub is indicative of pericarditis from any cause and does not imply malignancy. Rubs can still occur even when an effusion separates the two layers of the pericardium. Rubs usually disappear with effective therapy.
15. What would be the best first-line therapy for the patient in question 14?
A Acetaminophen
B Aspirin
C Ibuprofen
D Prednisone
E Colchicine
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15. The answer is C [VI A 4]. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen form the first line of therapy. High-dose aspirin is effective but is more likely to cause gastrointestinal tract side effects. Although acetaminophen might relieve the pain, it would not treat the inflammation. Prednisone and colchicine are reserved for NSAID failures.
16. Several days later, the patient develops dyspnea and jugular venous distension. The likely diagnosis now is:
A Right-sided heart failure
B Myocardial infarction
C Pulmonary embolism
D Pericardial tamponade
E Pneumonia
View Answer

16. The answer is D [VI C 2]. The onset of dyspnea and neck vein distention should immediately trigger concern for tamponade in a patient with known pericarditis. As fluid builds up in the pericardial sac, it compresses the heart, limits its output, and raises the pressure in all four cardiac chambers; hence the neck vein distention. Whereas MI, right-sided failure, pulmonary embolism, and pneumonia are all possible occurrences, there are no findings to confirm their presence in this otherwise healthy young woman.
A 75-year-old man complains of chest pain while climbing stairs. On physical examination, there is a II/VI systolic ejection murmur that radiates to the neck. The carotid upstrokes are delayed and diminished in volume.
17. The most likely diagnosis is:
A Hypertrophic cardiomyopathy
B Aortic stenosis
C Mitral stenosis
D Pulmonary stenosis
E Vasovagal syncope
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17. The answer is B [IV A 3 a–b]. The murmur and delayed carotid upstrokes are typical of the fixed LV outflow obstruction of aortic stenosis. Pulmonary stenosis also can cause chest pain and a systolic ejection murmur but would not cause carotid delay. Hypertrophic cardiomyopathy causes a spike and dome of the carotid upstrokes; that is, a sharp upstroke followed by fall and a flatter secondary rise. The murmur of mitral stenosis is diastolic. Although the syncope could have been attributable to a vasovagal faint, this could only be a diagnosis of exclusion in the face of obvious aortic stenosis.
18. The best test to confirm the diagnosis is:
A An ECG
B An exercise stress test
C An echocardiogram
D A radionuclide ventriculogram
E A chest x-ray
View Answer

18. The answer is C [IV A 4]. Echocardiography with Doppler interrogation of the valve will show the aortic stenosis, quantify its severity, and assess left ventricular function. The ECG and chest x-ray are nonspecific in this disease. Although useful in asymptomatic patients, stress testing is dangerous in symptomatic aortic stenosis. A radionuclide study would give information about left ventricular function but not about lesion severity.
19. The recommended therapy is:
A Urgent aortic valve replacement
B An ACE inhibitor
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C Nitroglycerine
D A calcium channel blocker
E A خ²-blocker
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19. The answer is A [IV A 5 b]. The only accepted therapy for symptomatic aortic stenosis is aortic valve replacement. Nitrates can be used cautiously for angina until the valve is replaced but only as a temporizing measure. The other agents listed could cause hypotension and should not be used.
A murmur is detected on the routine examination of a 35-year-old woman. She is entirely asymptomatic and engages in aerobic exercise classes without difficulty. On physical examination, there is II/VI systolic ejection murmur heard best in the left second interspace. S1 is normal. S2 is widely split and does not vary with respiration.
20. The likely diagnosis is:
A Pulmonary stenosis
B Aortic stenosis
C Ventricular septal defect
D Atrial septal defect
E A flow (innocent) murmur
View Answer

20. The answer is D [VII A 3 b]. The widely split S2 that does not vary with respiration is pathognomonic of atrial septal defect. The murmur is caused by increased flow across the pulmonic valve, which is not stenotic. The murmur of a ventricular septal defect is holosystolic. The murmur of aortic stenosis is associated with a soft single S2 because the aortic valve neither opens nor closes well.
21. Which of the following is true about this abnormality?
A This abnormality, when identified, should always be repaired.
B All types of this defect are associated with an increased risk of endocarditis.
C Uncorrected, this defect may lead to pulmonary hypertension and right heart failure.
D Ventricular arrhythmias are frequently associated with this abnormality.
E The murmur is due to turbulent flow across the defect.
View Answer

21. The answer is C [VII A 3 a]. Atrial septal defects may occur in different locations, and may be of different sizes. Large, nonrestrictive defects may lead to pulmonary hypertension and eventual right-sided heart failure if left uncorrected. Not all atrial septal defects are associated with an increased incidence of endocarditis. Endocarditis is more common is ostium primum atrial septal defects due the associated abnormality of the anterior mitral valve (cleft mitral valve). Ostium secundum defects, the most common type, are not associated with an increased risk. Atrial arrhythmias commonly occur late in the natural history of the disease, but ventricular arrhythmias are not commonly associated with atrial septal defects. The murmur associated with an atrial septal defect is due to the relative increase in blood flow across the pulmonic valve, and is not directly related to shunt flow across the atrial septal defect.
A 50-year-old man presents with mild dyspnea on exertion of recent onset. He was told that he had “a murmurâ€‌ during childhood, but he has not seen a physician in many years. On examination, his pulses are bounding and his blood pressure is 160/60 mm Hg. S1 is soft and S2 is normal. There is a soft apical diastolic low-pitched rumble heard at the apex, and there is a diastolic decrescendo murmur heard along the left sternal border extending to S1. Chest x-ray demonstrates cardiomegaly.
22. The most likely diagnosis is
A Aortic stenosis
B Aortic insufficiency
C Mitral stenosis
D Mitral insufficiency
E Mixed aortic insufficiency and mitral stenosis
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22. The answer is B [IV C 1-2]. The bounding pulses and widened pulse pressure are characteristic of significant aortic insufficiency and represent both the increased stroke volume and the enhanced aortic “run-offâ€‌ due to the incompetent valve. Because of retrograde diastolic flow across the aortic valve into the left ventricle, the left ventricular diastolic pressure rises rapidly, leading to a nearly or completely closed mitral valve at the time of ventricular systole, accounting for the soft S1. In mitral stenosis, S1 is usually loud until very late stages of the disease. The “preclosureâ€‌ of the mitral valve is also possibly the cause of a relative mitral stenosis/diastolic rumble, termed the “Austin Flintâ€‌ murmur. Cardiomegaly is present in the volume overloaded state of severe aortic insufficiency. By comparison, the left ventricle is protected from volume overload with pure mitral stenosis, and it is generally small in size.
23. An echocardiogram confirms your clinical suspicions. The left ventricular function is normal, but the left ventricle is dilated to 6 cm at end-systole. You should recommend which of the following treatments?
A Careful titration of a خ²-blocker
B Afterload reduction with an ACE inhibitor
C Mitral valve replacement
D Aortic valve replacement
E Mitral and aortic valve replacement
View Answer

23. The answer is D [IV C 5]. Patients with severe aortic valvular insufficiency with left ventricular dilation to this degree should be referred for aortic valve replacement. Medical therapy at this point is more likely to result in worse postoperative left ventricular function and more symptoms of heart failure. The use of خ²-blockers in patients with significant aortic insufficiency is controversial, as they prolong the diastolic interval and may, therefore, increase the regurgitant fraction of blood. Afterload reduction in patients with significant aortic regurgitation, but without this degree of ventricular dilation would be prudent and can delay left ventricular dilation and compromise of function.
A 35-year-old white woman enters the emergency department complaining of episodic chest pain that usually lasts for 5–10 minutes. Sometimes it is related to exercise, but on other occasions it occurs at rest. The pain does not radiate. The woman is a nonsmoker and has no history of hypertension. Two other family members have died of heart disease, one at 50 years of age and the other at 56 years of age. On physical examination, the patient is in no acute distress. Her blood pressure is 120/70 mm Hg and her pulse is 70 bpm. Examination of the precordium finds that the PMI is forceful. There is a II/VI systolic ejection murmur heard along the left sternal border that increases in intensity when the patient stands up. The ECG shows nonspecific ST-segment and T-wave abnormalities.
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24. Which of the following is the most likely diagnosis?
A Innocent flow murmur
B Aortic stenosis
C Hypertrophic cardiomyopathy
D Mitral stenosis
E Pulmonic stenosis
View Answer

24. The answer is C [V B 4]. The most likely diagnosis is hypertrophic cardiomyopathy, as evidenced by the increased intensity of the systolic ejection murmur when the patient stands. When a patient with hypertrophic cardiomyopathy stands, blood pools in the legs, decreasing left ventricular size and bringing the anterior leaflet of the mitral valve in closer contact with the hypertrophied ventricular septum. This increases the obstruction and makes the murmur louder. Conversely, innocent flow murmurs and the murmurs associated with pulmonic and aortic stenosis decrease when the patient stands, because the temporary pooling of central volume in the legs decreases forward cardiac output, thereby decreasing turbulent flow in the valve. The murmur of mitral stenosis is a diastolic murmur, not a systolic murmur.
25. Which of the following tools would be best to use when diagnosing this patient?
A Chest radiograph
B Cardiac catheterization
C Thallium scanning
D Echocardiography
E Myocardial biopsy
View Answer

25. The answer is D [V B 5(b)]. The echocardiogram is a highly effective diagnostic tool in hypertrophic cardiomyopathy, provided the patient can be visualized adequately. Asymmetric hypertrophy of the septum compared with the free cardiac wall confirms the diagnosis. If obstruction is present, there will also be systolic anterior motion of the mitral valve. There are no particular features of hypertrophic cardiomyopathy demonstrable on a chest radiograph. Thallium scintigraphy may show the hypertrophied septum, but this is not the optimum form of imaging. Cardiac catheterization can certainly confirm the diagnosis, but this invasive test needs to be performed in only a minority of patients when echocardiography cannot adequately visualize the patient's heart.
26. Which of the following therapies is most appropriate for this patient?
A Immediate surgery
B A خ²-blocker
C Vasodilators
D Digoxin
E Furosemide
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26. The answer is B [V B 6 a]. Symptoms of hypertrophic cardiomyopathy may be relieved with propranolol, a خ²-adrenergic blocking agent. By decreasing heart rate, propranolol allows increased left ventricular filling, thereby increasing separation of the anterior leaflet of the mitral valve and the septum and reducing the amount of obstruction. Unlike valvular aortic stenosis (where death may be imminent after the development of symptoms unless surgery is performed) in hypertrophic cardiomyopathy, there is no evidence that surgery prolongs life. Both digoxin (by increasing the force of that contraction) and furosemide (by decreasing left ventricular size) would worsen the obstruction and likely exacerbate the patient's symptoms.
27. Which of the following is true regarding percutaneous coronary intervention?
A There is no benefit over the use of intravenous thrombolytic agents for the treatment of acute myocardial infarction.
B In patients with stable anginal symptoms it provides symptom relief and a mortality benefit.
C Stents bonded with drugs such as sirolimus or paclitaxel have eliminated the risk of re-stenosis.
D One third of patients who undergo balloon angioplasty alone will develop re-stenosis within 6 months.
E Periprocedural administration of glycoprotein IIb/IIIa antagonists enhances short-term, but not long-term patency rates and clinical success.
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27. The answer is (D) [III A 5 a (4) (d)]. The restenosis rate associated with balloon angioplasty alone is 33% within 6 months. Stents were developed, in part, to decrease the incidence of restenosis. While they have achieved this goal, they have not eliminated the risk totally. The use of glycoprotein IIb/IIIa antagonists has improved both short- and long-term clinical success rates and angiographic patency rates. When percutaneous intervention is readily accessible for patients undergoing treatment for acute myocardial infarction, the angiographic patency rates and clinical outcomes are better with the use of direct PCI. Patients with stable anginal symptoms may have symptomatic benefit from PCI, but do not enjoy a mortality benefit related to the procedure.

Cardiovascular Syncope

Cardiovascular Syncope
A. Definition
Syncope is a sudden loss of consciousness of brief duration.
B. Pathophysiology
Cardiovascular syncope occurs when the brain's metabolic needs cannot be met by the available blood supply. Adequate perfusion is dependent on an adequate systemic blood pressure: BP = CO أ— SVR (where BP = blood pressure, CO = cardiac output, and SVR = systemic vascular resistance). Therefore, a fall in cardiac output or a fall in systemic vascular resistance can precipitate a fall in blood pressure, leading to syncope. Because CO = SV أ— HR (where SV = stroke volume and HR = heart rate), either inadequate stroke volume or inadequate heart rate reduces cardiac output, potentially leading to hypotension and syncope.
C. Etiology
1. Reduced cardiac output
a. Bradycardia
(1) Heart block. A block in the cardiac conduction pathway may prevent the SA nodal electrical signal for ventricular contraction from being transmitted, in turn causing bradycardia. Whether syncope occurs depends on whether an alternative, lower pacemaker (e.g., the AV junction) produces an escape rate that is sufficiently fast to maintain blood pressure.
(2) Sick sinus syndrome occurs when there is a deficit in impulse generation from the SA node, which may lead to bradycardia and syncope.
(a) Profound sinus bradycardia, sinus arrest, and the tachycardia–bradycardia syndrome are the arrhythmias that constitute the sick sinus syndrome. The tachycardia–bradycardia syndrome is one of atrial instability where supraventricular tachycardia halts abruptly and is followed by severe bradycardia.
(b) Sick sinus syndrome may result from ischemic heart disease and idiopathic or inflammatory degeneration of the SA node.
b. Impaired stroke volume. The rhythmic filling and emptying of the left ventricle generates its stroke volume; therefore, conditions that either inhibit left ventricular filling or inhibit left ventricular emptying can severely reduce stroke volume, leading to hypotension and syncope.
(1) Conditions that limit left ventricular filling
(a) Obstruction to inflow. Any mechanical block in the cardiovascular system that inhibits filling of the left ventricle impairs its output. Such obstructions include mitral stenosis, left atrial myxoma, right atrial myxoma, pulmonary embolism, and pulmonic stenosis.
(b) Tachycardia. Both ventricular tachycardia and very rapid supraventricular tachycardia reduce the diastolic filling period of the left ventricle, limiting its filling and reducing its stroke volume. In ventricular tachycardia, the shortened diastolic filling period is compounded by incomplete ventricular relaxation, which further limits filling.
(c) Impaired systemic venous return. Failure of adequate systemic venous return to the right heart subsequently impairs its output to the left heart, impairing left ventricular stroke volume.
(i) Typically, impaired venous return occurs when the supine patient assumes the upright posture.
(ii) Normally, the tendency for gravity-induced venous pooling of blood in the legs is offset by venous vasoconstriction, which helps maintain venous return. However, in the face of dehydration, antihypertensive drugs, or autonomic dysfunction, impaired venous return may produce orthostatic syncope. Autonomic dysfunction may be idiopathic; familial; surgically induced; or result from diabetes, alcoholism, or pyridoxine deficiency.
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(2) Conditions that impair left ventricular emptying. The left ventricle may be impaired from emptying either as a result of a severe, sudden depression in myocardial contractile function or as a result of outflow obstruction.
(a) Decreased myocardial contractility. The sudden and severe degree of contractile depression required to cause syncope is almost invariably caused by global ischemia produced by left main or triple-vessel coronary disease, acute MI, ventricular tachycardia, or ventricular fibrillation.
(b) Obstruction to outflow. Obstruction of left ventricular outflow that produces syncope is caused by valvular aortic stenosis and hypertrophic cardiomyopathy.
2. Reduced total peripheral resistance. If cardiac output is maintained but total peripheral resistance falls, blood pressure also falls, potentially causing syncope.
a. An inappropriate fall in total peripheral resistance is usually operative in the common fainting spell. Increased blood flow to the skeletal muscles due to a fall in total peripheral resistance may divert flow from the brain and result in fainting. Venodilation and relative bradycardia may further compound the “vasovagal faintâ€‌ by reducing venous return and cardiac output.
b. Reduced total peripheral resistance leading to syncope may also occur in drug-induced, familial, or idiopathic autonomic dysfunction.
D. Diagnosis
A single fainting episode or episode of light-headedness occurs in more than 50% of the population at some point in a lifetime. It would be impossible to explore the cause of the event extensively in every affected patient. A good history and physical examination should be adequate to exclude potentially serious causes of a single episode of syncope. However, recurrent syncope requires a more extensive workup.
1. History. A thorough patient interview can reveal clues that may point to a specific etiology for the recurrent syncope.
a. A history of palpitations might indicate an arrhythmia.
b. The observation that syncope occurred upon assumption of an upright position suggests orthostatic hypotension.
c. A history of chest pain might indicate an ischemic event or pulmonary embolism.
d. A change in antihypertensive medication or a recent episode of dehydration are additional clues.
e. A history of a prior MI and reduced left ventricular function suggests the possibility of a ventricular arrhythmia.
2. Physical examination. Those maneuvers that might reveal a reason for hypotension and possible syncope should be emphasized.
a. Blood pressure
(1) The blood pressure should be recorded in both arms in both the supine and the sitting or standing positions.
(2) On assuming an upright posture, it is normal for systolic blood pressure to fall slightly while diastolic pressure increases. There is also usually a slight increase in heart rate.
(a) A frank decline in systolic and diastolic pressure on assuming an upright posture may indicate volume depletion or sympathetic compensation that is inadequate to counteract the change in posture.
(b) A fall in diastolic pressure of more than 10 mm Hg is significant and may suggest an orthostatic etiology of the syncope.
b. Heart rate and rhythm. The pulse should be examined for an extended period of time in an effort to detect arrhythmia or bradycardia.
c. Valvular obstruction. The murmurs and physical findings associated with mitral stenosis, aortic stenosis, pulmonic stenosis, or idiopathic hypertrophic subaortic stenosis should be recognized as indications of potentially correctable mechanisms for syncope.
d. Thromboembolism. Thrombophlebitis in the lower limbs indicates a source of pulmonary emboli, which can cause syncope. Physical evidence that a pulmonary embolus is present includes wheezing, increased intensity of the pulmonary component of the S2, and jugular venous distention.
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3. Electrocardiography. If second- or third-degree AV block is detected, it demonstrates the likely cause of the syncope. Bundle branch block and arrhythmias, or both, on the standard ECG should raise suspicion that heart block or arrhythmia are syncopal etiologies.
4. Holter monitoring. If the history, physical examination, and ECG point to an arrhythmia as the potential cause of the syncope, Holter monitoring may be performed. It records each heart beat over a 24-hour period, which is then reviewed for arrhythmia. Unfortunately, because most arrhythmias occur sporadically, most Holter monitor examinations are negative even when an arrhythmia is the source of the syncope.
5. Event monitors. These devices are worn or carried for several weeks. They are activated by the patient at the time of symptoms and document the rhythm before and after activation. The recording is then reviewed for arrhythmia.
6. Electrophysiologic testing. If the initial work-up demonstrates that heart disease is present but fails to demonstrate a specific cause of syncope, electrophysiologic stimulation may provoke the arrhythmia responsible for the syncope. Having established an arrhythmic cause, the proper therapy may then be instituted.
E. Therapy
1. Therapy for bradyarrhythmias. When a bradyarrhythmia has been established as the cause of the syncope, drug-induced bradycardia should be ruled out as a cause by discontinuing potentially offending drugs. If symptomatic bradycardia persists, a permanent pacemaker is indicated.
2. Therapy for tachyarrhythmias
a. Drug therapy for both ventricular and supraventricular tachyarrhythmias that have caused an episode of syncope is clearly indicated [see II D 1 b (3)]. In general, such therapy should be guided by electrophysiologic testing.
b. Antitachycardia pacemakers or implantable defibrillators may be used to electrically correct arrhythmias if drug therapy fails.
3. Therapy for autonomic dysfunction. If autonomic dysfunction is the cause of orthostatic hypotension and syncope, little can be done directly to treat the underlying cause. Instead, therapies to protect the patient from possible hypotension should be instituted. These include high salt intake or fludrocortisone to ensure volume expansion, support stockings to prevent venous pooling, or midodrine to increase peripheral vascular resistance. There may be a role for permanent cardiac pacing in a select group of patients for whom other forms of therapy have failed.
4. Correction of mechanical obstructions to cardiac inflow or outflow. Any fixed valvular lesion that has caused an episode of syncope should be corrected. If idiopathic hypertrophic subaortic stenosis is determined to be the cause of the syncope, standard therapy with propranolol or verapamil is indicated to reduce the amount of outflow obstruction. If medical therapy fails, myomectomy or alcohol septal ablation may be necessary.

Venous Thrombosis

Venous Thrombosis
A. Deep venous thrombosis
1. Definition. Deep venous thrombosis occurs when a blood clot forms in the lower extremities or in the pelvic veins. The gravity of deep venous thrombosis stems from the tendency of the thrombi to become pulmonary emboli. This tendency is especially pronounced for clots located above the popliteal fossa.
2. Predisposing factors
a. Immobilization. The muscles in the legs act as pumps to maintain venous return from the lower extremities. Inactivity of these muscles leads to venous stasis, with subsequent development of thrombophlebitis. Stasis is likely to occur during surgery, prolonged bed rest, and prolonged periods in one position.
b. Venous incompetence. Venous valvular incompetence and the presence of varicose veins increase the incidence of thrombophlebitis.
c. CHF. In CHF, cardiac output is reduced, as is venous return from the legs.
d. Injury. Direct mechanical injury to the lower extremities may lead to blood clot formation and the development of thrombophlebitis.
e. Hypercoagulable states. Malignancy, estrogen use, and hyperviscosity syndrome may produce a hypercoagulable state, increasing the risk of thrombophlebitis.
3. Clinical features
a. Symptoms. The patient usually presents with unilateral leg pain and swelling.
b. Physical signs. In general, the physical examination is unreliable. Tenderness on compression of the calf muscles, increased resistance during dorsiflexion of the foot (Homans' sign), and an increase in the circumference of the affected leg by at least 1 cm suggest the presence of deep venous thrombosis.
4. Diagnosis
a. Noninvasive studies. Impedance plethysmography and Doppler ultrasonography are useful tests for the detection of deep venous thrombosis.
b. Invasive studies. Contrast venography currently is the most effective way to demonstrate the area of blood clot. This technique is associated with complications, including adverse reactions to the contrast agent and postvenography thrombophlebitis.
5. Therapy. Anticoagulants prevent additional clot formation and allow the body's autolytic system to lyse effectively and heal deep venous thrombosis. Anticoagulation therapy is usually maintained for 3–6 months.
a. Anticoagulation with intravenous heparin is indicated in the acute treatment of deep venous thrombosis. LMWH appears to be as effective as unfractionated heparin. Although the low–molecular-weight form is more expensive, it does not require laboratory monitoring. In cases of heparin-induced thrombocytopenia, a direct thrombin inhibitor should be substituted for heparin.
b. After adequate treatment with heparin, oral anticoagulation with warfarin is begun.
6. Prophylaxis. There is substantial medical evidence that the incidence of deep venous thrombosis for hospitalized patients can be reduced by the following methods.
a. Rapid mobilization. Prolonged bed rest should be avoided when possible. The increasingly rapid mobilization of patients following MI has significantly reduced the incidence of thromboembolic complications following this disease.
b. Increasing deep venous flow
(1) Antithromboembolic stockings and pneumatic compression devices compress the superficial veins, thereby increasing deep venous flow and reducing stasis and the incidence of thromboembolism.
(2) Foot exercises and avoidance of leg crossing are further methods of preventing deep venous thrombosis.
c. “Minidoseâ€‌ heparin. Intermittent doses of subcutaneous heparin given at 8- hour intervals inhibit factors X and XI in the clotting cascade without producing overt anticoagulation. This treatment significantly reduces the incidence of deep venous thrombosis in both medical and surgical patients on bed rest.
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B. Superficial thrombophlebitis
Unlike deep venous thrombosis, in which a thrombus may break off and become a pulmonary embolism, superficial thrombophlebitis has little potential for embolic complications. Patients with superficial thrombophlebitis may present with a painful tender cord that can be easily palpated in the lower extremities. In the absence of concomitant deep venous thrombosis, anticoagulation is not indicated. Superficial thrombophlebitis is treated with elevation of the legs, heat, and administration of salicylates or other NSAIDs.

Congenital Heart Disease in the Adult

Congenital Heart Disease in the Adult
A. Atrial septal defect (Figure 1-12)
1. Classification
a. An ostium secundum atrial septal defect occurs in the midportion of the intra-atrial septum and is caused by failure of the septum secundum to form properly.
b. An ostium primum atrial septal defect results from improper septation of the endocardial cushion portion of the septum. It invariably involves the mitral valve, which is cleft and often regurgitant.
c. A sinus venosus–type atrial septal defect occurs high in the atrial septum and frequently is associated with anomalous drainage of one or more of the pulmonary veins into the right atrium.

FIGURE 1-12 Atrial septal defects. Shown here are several types of atrial septal defects: sinus venosus defects of the superior vena caval (SVC) and inferior vena caval (IVC) types, ostium secundum and ostium primum defects, and a coronary sinus defect. (Adapted from Perloff JK. The Clinical Recognition of Congenital Heart Disease. 4th ed. Philadelphia: WB Saunders, 1994:295.)

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d. Holt-Oram syndrome is characterized by the presence of a secundum defect together with bony abnormalities of the forearms and hands. This syndrome is a hereditary disease that is transmitted in an autosomal dominant fashion.
2. Pathophysiology
a. Left and right atrial pressures usually are equal in atrial septal defect; thus, no pressure gradient exists between the atria. However, the increased thickness of the left ventricle as compared with the right ventricle makes the left ventricle less compliant and, therefore, harder to fill. Blood flow takes the path of least resistance and thus is shunted from the left atrium to the right atrium. The net effect is to increase the volume work of the right ventricle.
b. The increased volume pumped through the pulmonary vasculature may lead to architectural changes in the pulmonary vasculature and to the development of irreversible pulmonary hypertension—a serious but rare late complication.
3. Clinical features
a. Symptoms. Patients with atrial septal defect may have a prolonged symptom-free period. Eventually, symptoms develop and may include palpitations as a result of atrial arrhythmias, fatigue, dyspnea on exertion, orthopnea, frequent respiratory tract infections, and symptoms of right ventricular failure.
b. Physical signs
(1) Wide and fixed splitting of the S2 is the classic finding in atrial septal defect. The increased cardiac flow through the right ventricle delays pulmonic valve closure, widening the normal splitting of the S2. Inspiration produces relatively little change in right-sided flow, so there is little respiratory variation in the splitting of the S2.
(2) Murmur. Under low pressure, blood flow from the left to the right atrium occurs through a wide aperture and produces no turbulence or murmur. However, the increased pulmonary blood flow in atrial septal defect produces a systolic ejection murmur, which is heard in the pulmonic area. The increased flow also may produce a diastolic rumble across the tricuspid valve if the left-to-right shunt ratio is greater than 3:1.
(3) Neck vein distention, ascites, and edema are indicative of right ventricular failure.
4. Diagnosis
a. Electrocardiography. In ostium secundum defects, incomplete right bundle block and right axis deviation are common findings. Ostium primum defects usually involve the anterior fascicle of the left bundle, producing left anterior hemiblock and left axis deviation.
b. Chest radiography
(1) Increased pulmonary blood flow produces increased pulmonary vascular markings in the lungs, which is called shunt vascularity.
(2) Right ventricular enlargement may encroach on the retrosternal airspace, reducing it in the lateral view.
(3) Enlargement of the pulmonary artery segment in the posteroanterior view also may be seen.
c. Echocardiography
(1) The echocardiogram shows enlargement of the right ventricle, and the atrial septal defect itself may be seen in many cases.
(2) A saline injection, which carries with it micro bubbles of air, shows a negative-contrast image at the site of the defect.
(3) Doppler examination of the interatrial septum demonstrates the abnormal presence of left-to-right blood flow across the septum.
d. Cardiac catheterization
(1) During cardiac catheterization, the diagnosis can be confirmed by passage of the catheter across the atrial septal defect.
(2) Left and right atrial pressures usually are equal.
(3) Oxygen samples drawn from the superior vena cava and right atrium demonstrate a step-up in oxygen concentration in the right atrium, as highly oxygenated left atrial blood is shunted into the right atrium. Oxygen saturations can be used to quantitate the magnitude of the left-to-right shunt.
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5. Therapy
a. Surgical correction, which has a low operative mortality rate, is indicated for shunts with a pulmonary-to-systemic flow ratio of greater than 2:1, even in asymptomatic patients. Shunts of this magnitude may lead to the development of pulmonary hypertension, usually become symptomatic, and worsen with age.
b. Alternatively, several catheter-based devices for defect closure are now approved for use.
B. Ventricular septal defect
1. Pathophysiology. In ventricular septal defect, the left ventricle actively propels the blood into the right ventricle, resulting in the taxation of both ventricles and in increased pulmonary blood flow. Pulmonary hypertension is more severe and more frequent in ventricular septal defect than in atrial septal defect.
2. Clinical features. Because most ventricular septal defects lead to symptoms and are corrected in childhood, significant congenital ventricular septal defect rarely is diagnosed for the first time in adulthood.
a. Symptoms of ventricular septal defect are those of both left- and right-sided CHF.
b. Physical signs
(1) Displacement of the PMI to the left is indicative of left ventricular enlargement.
(2) Sternal lift is indicative of right ventricular enlargement.
(3) Murmur. A harsh, holosystolic murmur is heard along the left sternal border. The murmur often is accompanied by a thrill and radiates to the right of the sternum.
(4) Aortic regurgitation. Ventricular septal defects may involve the right coronary cusp of the aortic valve, producing insufficient support for this valve leaflet and, hence, aortic regurgitation. Approximately 6% of patients with ventricular septal defect have signs of aortic insufficiency.
3. Diagnosis
a. Electrocardiography. The ECG typically shows biventricular hypertrophy.
b. Chest radiography. Cardiac enlargement is the rule. If the shunt is greater than 2:1 in magnitude, shunt vascularity usually is present.
c. Echocardiography. The septal defect frequently can be demonstrated during two-dimensional echocardiography. Left and right ventricular enlargement is seen as well. Doppler examination reveals abnormal blood flow from the left ventricle to the right ventricle.
d. Cardiac catheterization
(1) A left ventriculogram obtained in the left anterior oblique position demonstrates flow of contrast from the left ventricle across the septum into the right ventricle.
(2) During cardiac catheterization, an oxygen step-up occurs at the level of the right ventricle. Pulmonary hypertension, if present, can be quantified.
4. Therapy. Because patients with ventricular septal defects are prone to pulmonary vascular complications and bacterial endocarditis, ventricular septal defects with a magnitude of 2:1 or greater should be corrected surgically.
C. Patent ductus arteriosus
1. Pathophysiology. In patent ductus arteriosus, blood flows from the aorta into the pulmonary artery after the takeoff of the left subclavian artery. Volume overload is imposed on the left ventricle, which must pump blood into both the systemic and pulmonary circulations, and, in time, may lead to left ventricular failure. The increased pulmonary blood flow created by this lesion may lead to the development of pulmonary hypertension, imposing a pressure overload on the right ventricle.
2. Physical signs
a. Murmur. Throughout the cardiac cycle, the vascular resistance and pressure in the pulmonary circuit are lower than the resistance and pressure in the aorta. Therefore, blood is shunted from left to right in both systole and diastole, and a continuous murmur with systolic and diastolic components is heard.
b. Pulses. The presence of a low-pressure, low-resistance pathway allows for increased aortic runoff in diastole, which produces bounding, full pulses similar to those found in aortic insufficiency.
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3. Diagnosis
a. Chest radiography reveals an enlarged cardiac silhouette with the presence of shunt vascularity. In adults, the patent ductus may become calcified, rendering it visible on the chest radiograph.
b. Echocardiography may reveal the patent ductus. Doppler interrogation detects abnormal flow of blood from the aorta to the pulmonary artery.
c. Cardiac catheterization
(1) During cardiac catheterization, the catheter usually can be passed from the pulmonary artery into the descending aorta, confirming the presence of a patent ductus arteriosus.
(2) Oximetry can be used to quantify the magnitude of the left-to-right shunt.
(3) Aortography demonstrates the flow of contrast from the aorta through the patent ductus into the pulmonary artery.
d. Cardiac multislice CT or MRI may also demonstrate a patent ductus arteriosus.
4. Therapy. Catheter-based closure or surgical closure of the patent ductus is indicated in adults with a shunt ratio of greater than 2:1.
D. Coarctation of the aorta
This defect is a stenosis of the aorta, usually at the site of the ductus arteriosus.
1. Pathophysiology. Coarctation of the aorta often leads to hypertension.
a. If the stenosis is severe, it limits aortic blood flow distal to the constriction. Distal tissues are perfused by an extensive collateral arterial circulation.
b. Whereas renal blood flow and renal function usually are normal in adults with coarctation of the aorta, the kidneys still are perfused at a subnormal blood pressure.
2. Clinical features. If the coarctation does not cause heart failure due to pressure overload in childhood, it may not be detected until it manifests as hypertension in the adult.
a. Symptoms. Patients with coarctation may complain of headache, claudication, and leg fatigue.
b. Physical signs
(1) Blood pressure determined in the arms usually is elevated, whereas pulses and blood pressure in the legs usually are reduced, representing the gradient across the coarctation.
(2) Habitus. The upper body usually is well developed, whereas the legs occasionally appear underdeveloped.
(3) Murmur. Typically, a midsystolic murmur is heard over the back. If the stenosis is severe, a continuous murmur may be heard. Continuous murmurs also may be heard diffusely over the chest cavity as the result of increased flow through collateral vessels.
3. Diagnosis
a. Electrocardiography. The ECG shows left ventricular hypertrophy.
b. Chest radiography. Cardiac enlargement usually is seen. Dilation of the aorta proximal and distal to the coarctation with indentation at the site of the coarctation may cause the aorta to assume a figure “3â€‌ appearance. Dilation of chest wall arteries forming the collateral pathways produces rib notching.
c. Cardiac catheterization. During cardiac catheterization, the gradient across the coarctation can be measured. Aortography also allows visual demonstration of the coarctation.
d. Cardiac multislice CT or MRI may also reveal a coarctation of the aorta.
4. Therapy. Surgical correction of the coarctation is standard therapy. Percutaneous balloon aortoplasty with or without stenting may be a suitable alternative for selected patients.
5. Complications. Hypertension, infective endocarditis, dissection of the thoracic aorta, and rupture of cerebral (berry) aneurysms are seen frequently. Hypertension may persist even after the coarctation is repaired.
E. Ebstein's anomaly of the tricuspid valve
1. Pathophysiology. In Ebstein's anomaly, the tricuspid valve is situated abnormally low in the right ventricle. Part of the tricuspid valve is tethered directly to the right ventricle. Thus, a portion of the right ventricle actually lies above the AV groove and is “atrialized,â€‌ reducing the size of the right ventricle and usually resulting in tricuspid regurgitation. A coexistent atrial septal defect occurs in approximately 75% of cases.
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2. Clinical features
a. Symptoms. Depending on the degree of tricuspid regurgitation and whether an atrial septal defect exists, a patient's status may range from asymptomatic to cyanotic.
(1) Dyspnea on exertion, peripheral edema, and other symptoms of right ventricular failure frequently are encountered.
(2) Palpitations also are common in this anomaly, which is associated with Wolff-Parkinson-White (WPW) syndrome in approximately 10% of patients. WPW syndrome is characterized by abnormal ventricular conduction as the result of a congenital short circuit of the conducting system. Tachyarrhythmias are common.
b. Physical signs
(1) Tricuspid regurgitation. A large v wave in the neck veins and a pulsatile liver reflect tricuspid regurgitation.
(2) Heart sounds. Wide splitting of the S1 and S2 is heard. Because an S3 and an S4 often also exist, a quadruple or quintuple cadence is a common auscultatory finding.
(3) Murmur. The holosystolic murmur of tricuspid regurgitation is heard along the sternal border and may be accompanied by a systolic thrill.
3. Diagnosis
a. Electrocardiography. The ECG may show evidence of WPW syndrome (a short PR interval and a slurred QRS upstroke). Other findings include right atrial enlargement and right bundle branch block.
b. Echocardiography. The echocardiogram in Ebstein's anomaly shows delayed closure of the tricuspid valve in relation to the mitral valve. The inferior and leftward displacement of the tricuspid valve usually can be demonstrated.
4. Therapy. Tricuspid valve replacement and closure of the atrial septal defect may be useful in patients who have developed early signs of right ventricular failure.
F. Eisenmenger's syndrome
1. Pathophysiology. In Eisenmenger's syndrome, which can occur with any intracardiac shunt, the left-to-right shunt is reversed to produce a right-to-left shunt. Reversal occurs as a result of pulmonary vascular disease that leads to increased pulmonary vascular resistance. Increased pulmonary vascular resistance leads to decreased right-sided compliance and increased right-sided pressures, which produce right-to-left shunting.
2. Clinical features
a. Cyanosis may be constant or noted only during exercise. Differential cyanosis may occur in the presence of a patent ductus arteriosus; the preductal tissues (including the upper trunk) are pink, and the postductal tissues are cyanotic.
b. Angina. Patients with Eisenmenger's syndrome may experience exertional chest pain, which occurs even in the presence of normal coronary arteries. Reduced myocardial oxygenation and increased right ventricular wall stress may be factors causing the symptom.
c. Heart failure. Dyspnea on exertion, ascites, and peripheral edema are common.
3. Diagnosis
a. Electrocardiography. Right ventricular hypertrophy invariably is present.
b. Echocardiography. Saline injection demonstrates right-to-left shunting of micro bubbles in the presence of either an atrial or a ventricular septal defect. Doppler examination also demonstrates the abnormal right-to-left blood flow at the site of the shunt.
c. Laboratory data. Due to chronic hypoxemia, patients with Eisenmenger's syndrome are polycythemic. Hemoglobin concentrations in excess of 20 g/dL are common.
d. Cardiac catheterization. Right-sided pressures are extremely elevated. Oximetry is used to quantitate the right-to-left shunt. Administration of 100% oxygen via a rebreathing mask does not significantly correct the arterial desaturation.
4. Therapy. Surgical therapy generally is not successful.
a. Closure of the shunt site, which acts as an escape valve for the right ventricle, increases right ventricular pressures and causes worsening of right ventricular failure.
b. Phlebotomy may be necessary to avoid hyperviscosity by maintaining the hemoglobin level at less than 20 g/dL.

Pericardial Disease

Pericardial Disease
A. Acute pericarditis
1. Etiology
a. Myocardial infarction (MI). Pericarditis may occur in the first 24 hours following transmural MI because the inflamed surface of the infarcted area of myocardium produces pericardial irritation. A second type of pericarditis, called Dressler's syndrome, also may be seen from 1 week to several months after MI and may occur as the result of an autoimmune reaction to the damaged heart muscle.
b. Infection. Pericarditis frequently follows upper respiratory tract viral infections and is seen in many viral infections, including HIV, hepatitis, and many more. Tuberculosis, streptococcal infection, staphylococcal infection, and the sequelae of infective endocarditis also may produce pericarditis.
c. Collagen vascular disease. Acute pericarditis may be a clinical manifestation of SLE, rheumatoid arthritis, or, less commonly, scleroderma.
d. Drugs. Commonly used drugs that may cause acute pericarditis include procainamide, hydralazine, and isoniazid.
e. Malignancy. Pericarditis may occur secondary to metastatic involvement of the pericardium. Pulmonary and breast carcinomas are the most common primary sites.
f. Uremia. Pericarditis is common in untreated or undertreated severe chronic renal failure.
g. Postpericardiotomy syndrome. During open heart surgery, the pericardium is incised. Usually, the pericarditis that arises from this injury is short-lived; however, it may be protracted and severe in some patients.
h. Radiation. Radiation therapy delivered to the chest for thoracic malignancies may cause pericarditis.
2. Clinical features
a. Symptoms. The most common symptom in pericarditis is inspiratory chest pain.
(1) The pain is located in the left side and often is lessened when the patient sits up and leans forward.
(2) Occasionally the pain may be similar to that of myocardial ischemia and may radiate to the neck and arm.
b. Physical signs. The classic sign of acute pericarditis is the pericardial friction rub, which is a scratchy, leathery sound with three components corresponding to ventricular systole, early diastolic filling, and atrial contraction.
3. Diagnosis
a. Physical examination. The presence of a pericardial friction rub confirms the diagnosis of pericarditis.
b. Electrocardiography. Epicardial inflammation produces a diffuse current of injury with ST-segment elevation throughout the ECG. There is no reciprocal ST-segment depression, as is seen in acute MI. Depression of the PR segment is unique to pericarditis.
c. Echocardiography. The echocardiogram frequently demonstrates a pericardial effusion, which helps confirm the diagnosis.
4. Therapy
a. Specific therapy should be directed toward the cause of the pericarditis, if the cause is known.
b. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, indomethacin, and ibuprofen usually are effective in reducing the inflammation and relieving the chest pain.
c. Colchicine. Intractable cases of pericarditis, as may occur with Dressler's syndrome and postpericardiotomy syndrome, may require glucocorticoid therapy for relief of symptoms. Recently colchicine has replaced steroids at many centers.
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B. Pericardial effusion
1. Pathophysiology. The inflammation caused by acute pericarditis often produces exudation of fluid into the pericardial space. When fluid accumulates slowly, the pericardium expands to accommodate it, but when fluid accumulates rapidly, it compresses the heart, thus inhibiting cardiac filling. This latter condition is known as cardiac tamponade (see VI C).
2. Clinical features
a. Symptoms. The mere presence of a pericardial effusion does not cause symptoms. However, symptoms of acute pericarditis may coexist with a pericardial effusion.
b. Physical signs. As the effusion accumulates, it acts as a cushion around the heart.
(1) The precordium becomes quiet, palpation of the PMI becomes difficult, and the heart tones become distant and soft.
(2) Although the accumulation of fluid between the layers of pericardium may diminish a pericardial friction rub, a friction rub still may exist in the presence of a large effusion.
3. Diagnosis
a. Electrocardiography. The ECG demonstrates low voltage; electrical alternans may be present n large effusion.
b. Chest radiography. Cardiac enlargement occurs as the effusion develops. Typically, the cardiac silhouette has a “water bottleâ€‌ appearance. The presence of an extremely enlarged heart without signs of vascular congestion suggests the diagnosis of pericardial effusion.
c. Echocardiography. An echocardiogram demonstrating an echo-free space between the two layers of the pericardium is diagnostic of a pericardial effusion.
d. Pericardiocentesis. The presence of a pericardial effusion may be confirmed by the aspiration of fluid from the pericardial sac. Examination of the fluid helps establish the cause of the effusion.
(1) The fluid should be sent for a cell count and differential, bacterial and fungal cultures, stains and cultures for Mycobacterium tuberculosis, protein content, and lactate dehydrogenase (LDH) content.
(2) An additional aliquot of fluid should be centrifuged and examined for tumor cells.
(3) Bloody effusions are characteristic of certain etiologies (e.g., neoplasia, tuberculosis). However, bloody effusions can also occur if the needle is passed too far and ventricular blood is aspirated by mistake. It is possible to distinguish the two because ventricular blood clots, whereas a bloody effusion does not.
e. Therapy. Treatment for a pericardial effusion is the same as that for acute pericarditis but may also involve aspiration.
C. Cardiac tamponade
1. Definition and pathophysiology. Cardiac tamponade is a life-threatening condition in which a pericardial effusion has developed so rapidly or has become so large that it compresses the heart.
a. The heart cannot fill adequately, and because the heart can pump out only what it takes in, impaired filling causes a profound reduction in cardiac output.
b. The external pressure produced by the fluid on the four chambers of the heart is dispersed equally. Because external pressure usually rises to a greater level than the normal cardiac filling pressures, intrapericardial pressure, left and right atrial pressures, and left and right ventricular pressures all become equal in diastole.
2. Clinical features
a. Symptoms. Most patients with cardiac tamponade complain of dyspnea, fatigue, and orthopnea.
b. Physical signs
(1) Pulsus paradoxus. The normal fall in systolic blood pressure that occurs during inspiration is exaggerated in tamponade. A decrease of more than 10 mm Hg occurs in 95% of patients with cardiac tamponade. The presence of pulsus paradoxus implies that stroke volume is falling during inspiration, probably as a result of the following mechanisms:
(a) Septal shift. During inspiration, right ventricular filling is augmented by negative intrathoracic pressure, which increases venous return. This causes transient enlargement of the right ventricle and pushes the ventricular septum into the left ventricle, thus reducing the size and output of the left ventricle.
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(b) Tensing of the pericardium. Inspiration produces downward traction on the pericardium, further compressing the cardiac structures and reducing left ventricular output.
(c) Right ventricular enlargement. The enhanced right ventricular filling during inspiration also distends the right ventricle, causing it to take up more room in the pericardial space. This further limits left ventricular filling.
(d) Negative intrathoracic pressure. During inspiration, the negative pressure inside the chest subtracts pressure from the extrathoracic vasculature, further reducing blood pressure.
(e) Expansion of the pulmonary vascular bed. The pulmonary vascular bed expands during inspiration, increasing its capacity and, thus, reduces left atrial filling.
(2) Neck vein distention. The intrapericardial pressure and right atrial pressure is reflected by extreme elevation of the jugular venous pressure. However, Kussmaul's sign (i.e., increased neck vein distention with inspiration) usually is absent in this condition.
(3) Narrowed pulse pressure. Reduction in left ventricular stroke volume leads to a reduction in systolic pressure; the tachycardia that usually occurs as a compensatory mechanism diminishes diastolic runoff and maintains diastolic pressure. Thus, pulse pressure is narrowed; however, less severe cases of cardiac tamponade may coexist with a normal pulse pressure.
(4) Shock. The carotid upstroke is diminished in volume, the systolic blood pressure is reduced, and the periphery is cold and clammy because of the vasoconstriction present in reduced cardiac output states.
3. Diagnosis. Elevated neck veins, pulsus paradoxus, and an enlarged cardiac silhouette on chest x-ray in a patient exhibiting symptoms of compromised cardiac output strongly suggest the diagnosis.
a. Echocardiography is an indispensable tool in the evaluation of tamponade. Features consistent with tamponade include:
(1) Presence of a pericardial effusion,
(2) Collapse of the right atrium and/or right ventricle, which occurs in diastole as the pericardial pressure exceeds the intracavitary pressure,
(3) Enhanced inspiratory trans-tricuspid flow and simultaneously reduced trans-mitral flow. This is the echo equivalent of a pulsus paradoxus.
b. Cardiac catheterization, which could confirm the diastolic equalization of pressures, is less commonly used for diagnosis of tamponade.
4. Therapy. The only effective therapy for cardiac tamponade is removal of fluid from the pericardial sac. Thus, emergency pericardiocentesis is indicated. The use of pressor agents and volume expansion is of limited benefit until pericardiocentesis can be performed.
D. Constrictive pericarditis
1. Definition. Constrictive pericarditis is the diffuse thickening of the pericardium in reaction to prior inflammation, which results in reduced distensibility of the cardiac chambers. Cardiac output is limited, and filling pressures are increased to match the external constrictive force placed on the heart by the pericardium.
2. Etiology. Most conditions that cause acute pericarditis may lead to chronic constrictive pericarditis.
3. Clinical features
a. Symptoms. The clinical picture typically is dominated by symptoms of right-sided failure rather than left-sided failure.
(1) Most patients with constrictive pericarditis complain of dyspnea on exertion as a result of limited cardiac output. Although approximately 50% of patients complain of orthopnea, paroxysmal nocturnal dyspnea is rare.
(2) Symptoms related to systemic venous hypertension frequently are reported and include ascites, edema, and jaundice.
b. Physical signs
(1) Jugular venous distention. The jugular veins are distended, indicating systemic venous hypertension. Neck vein distention increases with inspiration (Kussmaul's sign).
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(2) Heart sounds. The heart sounds are distant. Early in diastole, a pericardial knock may be heard, which falls in the same cadence as an S3 but is higher pitched and corresponds to early, abrupt cessation of ventricular filling.
(3) Other signs of systemic venous hypertension. Ascites, edema, hepatic tenderness, and hepatomegaly are frequently present. It is not uncommon for constriction to masquerade as end-stage liver disease.
4. Diagnosis
a. Electrocardiography. The ECG shows low voltage in the limb leads. Atrial arrhythmias are common.
b. Chest radiography reveals pericardial calcification in 50% of patients. This finding is seen as a radiopaque ring around the heart in the lateral view. The heart usually is normal in size, although cardiomegaly occasionally is noted.
c. Echocardiography. Although pericardial thickening often can be detected, reliable diagnosis of constrictive pericarditis by echocardiography is difficult. However, Doppler interrogation of the mitral valve usually demonstrates an abnormal decrease in flow during inspiration.
d. Magnetic resonance imaging (MRI) gated to the cardiac cycle is an imaging technique capable of measuring pericardial thickness.
e. Cardiac catheterization reveals equal pressures in the four cardiac chambers during diastole; in addition, all pressures usually are elevated.
5. Therapy. Surgical removal of the pericardium is curative. However, immediate relief of constrictive symptoms may not occur for up to 6 weeks after pericardiectomy.

Cardiomyopathies

V. Cardiomyopathies
A. Dilated (congestive) cardiomyopathy
1. Definition. Dilated cardiomyopathy is defined as a diminution in the contractile function of the left, right, or both ventricles in the absence of pressure overload, volume overload, or coronary artery disease. The loss of cardiac muscle function results in CHF.
2. Etiology. The cause of most cases of dilated cardiomyopathy is unknown. Viral infection has been implicated in the pathogenesis of this disease, but proof of cause generally is lacking. The following other conditions have been linked to cardiomyopathy.
a. Prolonged ethanol abuse is the most common reversible cause of cardiomyopathy.
b. Doxorubicin therapy. High doses of doxorubicin, a commonly used chemotherapeutic drug, may result in irreversible dilated cardiomyopathy.
c. Exposure to mercury, lead, or high-dose catecholamines may cause myocardial damage and dilated cardiomyopathy.
d. Endocrinopathies, including thyrotoxicosis, hypothyroidism, and acromegaly, have been reported to cause dilated cardiomyopathy. In thyrotoxicosis and in hypothyroidism, the myopathy usually is reversed when the endocrinopathy is corrected.
e. Metabolic disorders (e.g., hypophosphatemia, hypocalcemia, thiamin deficiency) may produce reversible cardiomyopathy.
f. Hemoglobinopathies (e.g., sickle cell anemia, thalassemia) are associated with myocardial dysfunction.
g. Genetic abnormalities. In some families, the development of dilated cardiomyopathy is linked to specific genetic abnormalities.
h. Prolonged tachycardia (persisting for weeks or months) may result from uncontrolled atrial arrhythmias, causing a dilated cardiomyopathy that may be reversed within weeks, after heart rate is controlled.
3. Clinical features, diagnosis, and treatment of dilated cardiomyopathy are similar to left- and right-sided CHF as described in I D–F.
a. a. Symptoms of dilated cardiomyopathy are those of both left- and right-sided CHF as described in I D 1.







(1) Generally, the symptoms of left-sided failure (i.e., orthopnea, paroxysmal nocturnal dyspnea, and dyspnea on exertion) precede those of right-sided failure.
(2) Chest pain may occur in the absence of obstructive coronary disease. The cause of the chest pain may be the excessive oxygen demands of an enlarged, thin-walled ventricle with high wall stress.
b. Physical signs in dilated cardiomyopathy are those of CHF. A gallop rhythm is usually present. The murmur of mitral regurgitation also may be present. Mitral regurgitation occurs as a result of ventricular dilation and improper alignment of the papillary muscles.

4. Diagnosis

a. Electrocardiography reveals frequent left ventricular hypertrophy and nonspecific ST- and T-wave abnormalities. Left bundle branch block is common.
b. Chest radiography shows an enlarged heart, and there is evidence of pulmonary vascular congestion.
c. Echocardiography reveals dilated and poorly contracting left and right ventricles. In addition, secondary left and right atrial enlargement usually is seen.
d. Gated blood pool scanning in dilated cardiomyopathy reveals reduction of the ejection fraction of both ventricles. There usually is global dysfunction, but regional contractile abnormalities also may exist.
e. Cardiac catheterization usually is not necessary to make the diagnosis of dilated cardiomyopathy. However, because surgical correction of ischemic heart disease can occasionally improve left ventricular function, ischemic heart disease should be excluded prior to making the diagnosis of cardiomyopathy. In such cases, cardiac catheterization may be indicated.
5. Therapy

a. Removal of an offending agent. The most hopeful situation is one in which incessant tachycardia or a known toxin has caused ventricular dysfunction. Heart rate control or removal of the toxin from the patient's environment may lead to significant improvement in ventricular function.
b. Supportive therapy. When dilated cardiomyopathy is idiopathic, the symptoms of CHF can be improved by such measures as salt restriction and administration of cardiac glycosides, diuretics, vasodilators, and neurohumoral blockers. Evidence shows that the addition of ACE inhibitors to a standard regimen of diuretics increases longevity. Gradual introduction of خ²-blockers also prolongs life.
c. Cardiac transplantation. Cardiac transplantation may offer an improved quality of life to selected patients when control of CHF is not possible and prognosis is poor.
B. Hypertrophic cardiomyopathy
1. Definition. Hypertrophic cardiomyopathy is a disorder in which regional hypertrophy of the left ventricle occurs independent of loading conditions. It most commonly involves the interventricular septum, but can also involve the apex. When the septum is involved, the hypertrophied septum and the anterior leaflet of the mitral valve may produce dynamic left ventricular outflow obstruction.
2. Etiology. Most cases are inherited through an autosomal dominant mode of transmission, but sporadic cases also occur. Specific abnormalities in the genes coding for cardiac myosin and other cardiac proteins have been identified.
3. Pathophysiology
a. Methods of obstruction include the following:
(1) As shown in Figure 1-10, the hypertrophied septum encroaches on the left ventricular outflow tract and comes into close approximation with the anterior leaflet of the mitral valve.

FIGURE 1-10 Cardiac cross-section cut from the apex to the base in a patient with hypertrophic obstructive cardiomyopathy. The upper portion of the septum is thickened and comes into close proximity with the anterior leaflet of the mitral valve. (Adapted from Johnson R, et al. The Practice of Cardiology. Boston: Little, Brown, 1980:648.)





(2) During systole, a low-pressure zone may develop as blood flow accelerates through the narrowed area between the septum and the anterior leaflet, generating a Bernoulli effect. Thus, the anterior leaflet of the mitral valve is drawn into the septum (systolic anterior motion), leading to outflow obstruction.
(3) The septum itself shortens very little during systole because of its catenoid shape. Because the septum does not shorten, it cannot thicken. Therefore, it is the anterior leaflet of the mitral valve that plays the active role in creating the obstruction.
b. The degree of outflow obstruction varies from patient to patient and from time to time in the same patient.
(1) Physiologic conditions that enlarge the left ventricle (e.g., increases in preload and afterload) separate the septum and anterior leaflet of the mitral valve and reduce the obstruction.
(2) Physiologic conditions that make the ventricle smaller or that increase the velocity of blood flow (e.g., dehydration, positive inotropic drugs) increase the degree of obstruction.
c. The obstruction to outflow may cause secondary cardiac hypertrophy of the nonseptal portions of the ventricle, but septal thickness generally remains greater than that of the free wall of the ventricle.
4. Clinical features
a. Symptoms
(1) Angina. Patients with obstructive cardiomyopathy frequently complain of chest pain.
(a) The pain usually has atypical features; that is, the pain may occur at rest and is not always related to exercise.
The pathophysiology of angina in hypertrophic obstructive cardiomyopathy is unclear, but coronary blood flow is subnormal, potentially causing ischemia.
(2) Syncope
(a) Syncope usually occurs during or after exercise in patients with obstructive cardiomyopathy as a result of reduced left ventricular size and the consequent increased obstruction to outflow.
(i) After exercise, afterload is reduced because of peripheral vasodilation.
(ii) Preload is reduced because of the decreased activity of the contractions of the leg muscles, which help to return blood to the heart.
(iii) The inotropic state remains elevated because of the increased catecholamine level after exercise.





(b) Arrhythmias, which are common in this disorder, also may precipitate syncope or sudden death.
(3) CHF. Dyspnea on exertion, orthopnea, and paroxysmal nocturnal dyspnea occur in patients with obstructive cardiomyopathy. Systolic function usually is normal or supranormal, and the ejection fraction often exceeds 80%.
(a) The symptoms of heart failure usually are not caused by systolic malfunction, but rather occur as a result of increased diastolic stiffness.
(b) The thickened myocardium requires an increased filling pressure for adequate diastolic distention. The increased filling pressure is reflected to the lungs and produces pulmonary congestive symptoms.
(c) In the later stages of the disease, however, systolic dysfunction also may occur, contributing to the symptoms of CHF.
b. Physical signs
(1) Carotid upstroke. In patients with the obstructive form of the disease, the carotid upstrokes have a spike and dome character (Online Figure 1-11). This configuration indicates early systolic outflow followed by a period of obstruction, during which flow falls. The dome portion of the curve reflects the period near the end of systole when obstruction diminishes and aortic outflow again commences.


ONLINE FIGURE 1-11 Diagram showing simultaneous recording of the electrocardiogram (ECG), left ventricular pressure tracing (LV), and aortic pressure tracing (Ao) in a patient with hypertrophic obstructive cardiomyopathy. A large pressure gradient exists between the left ventricle and aorta. The aortic pressure tracing (similar to the carotid pulse) demonstrates a spike and dome configuration. (Reprinted from Cohn PF, Wynne J. Diagnostic Methods in Clinical Cardiology. Boston: Little, Brown, 1982:147, with permission.)

(2) Murmur. The murmur is a systolic ejection murmur heard along the left sternal border. Unlike the murmur in aortic stenosis, it does not usually radiate to the neck.
(a) Increasing the intensity of the murmur
(i) Maneuvers that diminish left ventricular size cause an increase in both the obstruction to outflow and the intensity of the cardiac murmur. Thus, the Valsalva maneuver, which diminishes the murmur in valvular aortic stenosis by diminishing flow, increases the murmur in obstructive cardiomyopathy by increasing obstruction.
(ii) Having the patient stand or inhale amyl nitrite also diminishes left ventricular size and therefore increases the intensity of the murmur.
(b) Diminishing the intensity of the murmur. Squatting, which increases myocardial afterload and venous return to the heart, increases cardiac size and, therefore, diminishes the murmur.
5. Diagnosis
a. Electrocardiography almost always is abnormal. The ECG usually shows evidence of left ventricular hypertrophy, nonspecific ST- and T-wave abnormalities, and left atrial enlargement.
b. Echocardiography establishes the diagnosis in most patients.
(1) In patients with asymmetric septal hypertrophy without obstruction, increased septal thickness results in a septum-to-free wall thickness ratio of 1.3:1 or greater.
(2) Findings in the obstructive form of the disease include systolic anterior motion of the mitral valve, systolic fluttering of the aortic valve leaflets, and early closure of the aortic valve, corresponding to the spike and dome seen in the carotid pulse.
6. Therapy. Unlike aortic stenosis, in which relief of valvular obstruction relieves symptoms and prolongs life, there is no conclusive evidence that surgical relief of obstruction in obstructive cardiomyopathy prolongs life. Therefore, medical therapy is used first in an attempt to improve symptoms.
a. Medical therapy
(1) خ²-blockers are effective in relieving symptoms in this disease.
(a) خ²-blockade slows the heart rate, which increases left ventricular filling and size, diminishing obstruction.
(b) خ²-blockade also reduces the vigor of left ventricular contraction and, thus, decreases the velocity of blood flow, which also reduces the degree of obstruction.
(2) Calcium channel blocking agents. These agents are an alternative to خ²-blockers and have been shown to diminish the left ventricular outflow gradient. Verapamil is the calcium channel blocker most widely used in the treatment of this disease. Caution must be exercised in patients with CHF because verapamil may worsen failure and precipitate acute pulmonary edema.








(3) Digitalis is contraindicated in the hyperdynamic phase of the disease when obstruction is present and the left ventricular cavity is small, because digitalis increases the vigor of left ventricular contraction and thus increases the outflow obstruction.
b. Surgical therapy
(1) Myomectomy. Surgical reduction of the thickness of the left ventricular septum relieves the outflow gradient and symptoms in those patients who have not responded to medical therapy.
(2) Mitral valve replacement. Because it is the anterior leaflet of the mitral valve that produces the obstruction, mitral valve replacement is also effective in relieving obstruction.
(3) Intentional septal infarction. Transcatheter instillation of ethanol into the septal artery is performed to infarct the septum and reduce obstruction.
c. Antiarrhythmic therapy. Most patients with hypertrophic myopathy die suddenly. Patients with a family history of sudden death or a personal history of syncope or ventricular tachycardia are at high risk and should undergo electrophysiologic testing. Many patients receive implantable defibrillators.
C. Restrictive cardiomyopathy
1. Definition. The restrictive cardiomyopathies are a group of diseases in which the composition of the myocardium has changed so that it becomes stiffer. The increased stiffness of the myocardium restricts left ventricular filling, thereby reducing stroke output and increasing left ventricular filling pressure.
2. Etiology. Infiltrative diseases of the myocardium, which produce restrictive cardiomyopathy, include amyloidosis, hemochromatosis, idiopathic eosinophilia, carcinoid syndrome, sarcoidosis, and endomyocardial fibroelastosis.
3. Pathophysiology. Systolic function usually is normal in the early stages of the disease, but the altered properties of the myocardium increase diastolic stiffness. Thus, the left ventricular pressure is above normal at any diastolic left ventricular volume. Increased filling pressure produces pulmonary congestion. As the infiltrative process progresses, systolic function also is compromised.
4. Clinical features
a. Symptoms of both left-sided and right-sided CHF usually are present; the symptoms of right-sided failure are usually more prominent.
b. Physical signs include those present in left-sided and right-sided CHF.
5. Diagnosis
a. Electrocardiography. The ECG frequently shows low QRS voltages and nonspecific ST- and T-wave abnormalities. Conduction abnormalities are common.
b. Radiographs. Signs of pulmonary vascular congestion may coexist with normal heart size, because even when left ventricular systolic function fails in the later stages of the disease, the restriction to cardiac filling prevents cardiac dilation.
c. Echocardiography
(1) The echocardiogram may demonstrate thickening of the left and right ventricles. The combination of increased left ventricular thickness on the echocardiogram and decreased left ventricular voltage on the ECG is highly suggestive of restrictive cardiomyopathy.
(2) Doppler examination may reveal evidence of abnormal ventricular diastolic filling or altered compliance.
(3) Left and right ventricular chamber sizes usually are normal, whereas the left and right atria are increased in size.
(4) In amyloidosis, the myocardium may appear brighter than normal.
d. Cardiac catheterization. Often it is difficult to distinguish restrictive cardiomyopathy from constrictive pericarditis.
(1) A dip and plateau in the left and right ventricular filling pressures may be seen in both diseases.
(2) In restrictive cardiomyopathy, left and right atrial pressures and left and right ventricular filling pressures usually are not identical, as they are in constrictive pericarditis.
(3) Endomyocardial biopsy during cardiac catheterization may help establish the diagnosis.
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6. Therapy. Treatment for this group of diseases is limited.
a. In cases with a reversible etiology (e.g., hemochromatosis), direct therapy such as iron chelation may result in improvement.
b. When the cause of the disease cannot be treated, symptomatic therapy with diuretics to reduce the symptoms of congestion is indicated.

Valvular Heart Disease

IV. Valvular Heart Disease
A. Aortic stenosis
1. Etiology
a. Congenital aortic stenosis usually is detected in pediatric patients but occasionally becomes apparent in early adulthood.
b. Senile calcific aortic stenosis occurs when scarring and calcification of a tricuspid aortic valve lead to orifice narrowing in the sixth, seventh, and eighth decades of life. Although once considered a “degenerativeâ€‌ idiopathic disease, it is now clear that the pathology leading up to severe aortic stenosis is due to proliferative and inflammatory changes leading to calcification, similar to the development of the plaque in ASCAD.
c. Bicuspid aortic valve is a common congenital cardiac abnormality. The flow characteristics of the bicuspid valve are more turbulent than those of the normal valve, leading to valve injury, calcification, and stenosis in the fourth and fifth decades of life.
d. Rheumatic aortic stenosis never occurs alone and is always associated with mitral valve disease.
2. Pathophysiology. Aortic valve stenosis produces a pressure overload on the left ventricle due to the greater pressure that must be generated to force blood past the stenotic valve. This commonly leads to compensatory left ventricular hypertrophy.
3. Clinical features
a. Symptoms. Asymptomatic patients with aortic stenosis are at little risk for sudden death. However, this risk increases dramatically when symptoms develop.
(1) Angina occurs in 35%–50% of patients with aortic stenosis.
(a) Fifty percent of patients who develop this symptom die within 5 years of its onset unless aortic valve replacement is performed.
(b) Although the exact mechanism of angina is unknown, current data suggest that coronary blood flow reserve is impaired in the severely hypertrophied left ventricle. Impairment of the coronary blood flow reserve limits oxygen delivery to the myocardium and produces angina during exercise.
(2) Syncope occurs during exercise when total peripheral resistance falls due to local autoregulatory mechanisms [see IX B, C 1 b (2) (b)]. When aortic stenosis is present, cardiac output across the stenotic aortic valve cannot increase during exercise. Because total peripheral resistance falls, blood pressure must also fall, and syncope occurs.
(a) Other causes of syncope in aortic stenosis include a reflex vasodepressor response to high intraventricular pressure, atrial or ventricular arrhythmias, and heart block as a result of conduction system calcification.
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(b) After syncope occurs in patients with aortic stenosis, expected survival is 2–3 years without valve replacement.
(3) Heart failure. Fifty percent of patients who develop heart failure die within 1–2 years of presentation if the stenosis is not corrected. Heart failure occurs because the afterload placed on the myocardium becomes excessive and both contractile dysfunction and diastolic muscle dysfunction occur when the myocardium is exposed to a prolonged, severe pressure overload.
b. Physical signs
(1) Delayed carotid upstroke. In the presence of aortic stenosis, the carotid upstroke typically is delayed in timing and reduced in volume (pulsus parvus et tardus). This finding is the most reliable physical sign in gauging the severity of the disease.
(2) Systolic ejection murmur. A harsh, late-peaking systolic ejection murmur is heard in the aortic area and is transmitted to the carotid arteries. The murmur also may be reflected to the mitral area, producing the false impression that mitral regurgitation also is present (Gallavardin's phenomenon).
(3) Soft, single S2. Because the aortic valve is stenotic, its motion is severely impaired. The reduction in motion of the valve causes the aortic component (A2) of the S2 to be absent. Thus, the only component of the S2 that is heard is the pulmonic component (P2), which is normally soft.
(4) S4. An S4 usually is heard as a result of the reduced left ventricular compliance that occurs in left ventricular hypertrophy.
(5) Sustained, forceful apex beat. The point of maximal cardiac impulse usually is not displaced unless heart failure has occurred. However, the impulse is sustained and forceful throughout systole.
4. Laboratory diagnosis
a. Electrocardiography. The ECG usually shows evidence of left ventricular hypertrophy.
b. Echocardiography can rule out significant aortic stenosis if valve motion is shown to be normal. However, Doppler examination of the aortic outflow tract during echocardiography can accurately measure the pressure gradient across the aortic valve, and can be used to calculate the valve area.
c. Cardiac catheterization. Diagnosis and evaluation of the severity of aortic stenosis may be confirmed by cardiac catheterization, during which the pressure gradient across the valve is measured and the degree of stenosis is calculated.
5. Therapy
a. Palliative therapy
(1) Medical therapy has no definitive role in the treatment of aortic stenosis, but diuretics may temporarily relieve the symptoms of volume overload until mechanical relief of the obstruction is performed.
(2) Insertion and inflation of a large balloon in the aortic valve orifice (balloon valvuloplasty) also may produce a moderate improvement in the amount of obstruction and in the symptoms, but relief from using this technique is usually only temporary. It does not reduce the mortality expected if the disease is left untreated.
b. Curative therapy requires aortic valve replacement, which may be performed using a preserved human homograft valve, a bioprosthetic heterograft valve, a mechanical valve, or a pulmonary autograft.
(1) Homograft valves. The hemodynamic flow pattern is excellent, and patients with homograft valves do not require anticoagulation therapy. Availability of these valves is limited, because most suitable donors are also acceptable for whole heart donation in cardiac transplantation.
(2) Heterograft valves. Patients with heterograft valves do not require anticoagulation therapy, but the durability of the valve is limited, and deterioration after 10 years is common.
(3) Mechanical valves. Patients with mechanical valves do require anticoagulation therapy. However, these valves are more durable than bioprostheses.
(4) Autograft (Ross procedure). In this procedure, the patient's normal pulmonary valve is transplanted into the aortic position, where it has excellent durability and longevity. A
P.20homograft is then inserted into the pulmonary position, where low pressure enhances homograft longevity. In practiced hands, the results of this procedure are excellent.




B. Mitral stenosis
1. Etiology. Almost all cases of mitral stenosis in adults are secondary to rheumatic heart disease. Most cases occur in women.
2. Pathophysiology
a. Mitral valve stenosis impedes left ventricular filling, thereby increasing left atrial pressure as a pressure gradient develops across the mitral valve. Elevated left atrial pressure is referred to the lungs, where it produces pulmonary congestion. As the stenosis becomes more severe, it may significantly reduce forward cardiac output.
b. Because the right ventricle is responsible for filling the left ventricle, the burden of propelling blood across the stenotic mitral valve is borne by the right ventricle. The overload on the right ventricle may be increased further when secondary pulmonary vasoconstriction occurs. Thus, the right ventricle must generate enough force both to overcome the resistance offered by the stenotic valve and to propel blood through constricted pulmonary arteries. Consequently, pulmonary arterial pressure may increase to three to five times normal, eventually resulting in right ventricular failure.
3. Clinical features
a. Symptoms
(1) Left-sided failure. Dyspnea on exertion, orthopnea, and paroxysmal nocturnal dyspnea occur as a result of reduced left ventricular output and increased left atrial pressure. In mitral stenosis, the symptoms of left ventricular failure usually are not attributable to left ventricular dysfunction but, rather, to the mitral stenosis itself.
(2) Right-sided failure. When pulmonary hypertension occurs, the right ventricle may fail, producing edema, ascites, anorexia, and fatigue.
(3) Hemoptysis. The high left atrial pressure produced in mitral stenosis may lead to rupture of small bronchial veins, producing hemoptysis.
(4) Systemic embolism. Stagnation of blood in the enlarged left atrium and left atrial appendage occurs in mitral stenosis, particularly if atrial fibrillation is present. Under these circumstances, a thrombus may form in the left atrium and can become a source of systemic embolism.
(5) Hoarseness may occur in mitral stenosis as the enlarged left atrium impinges on the left recurrent laryngeal nerve (Ortner's syndrome).
b. Physical signs
(1) Atrial fibrillation. Frequently, an irregularly irregular cardiac rhythm indicative of atrial fibrillation is present.
(2) Pulmonary rales. Bilateral pulmonary rales occur secondary to elevated left atrial and pulmonary venous pressures.
(3) Increased intensity of the S1. The S1 usually increases in intensity because the transmitral gradient limits spontaneous diastolic mitral valve closure. Thus, the mitral valve remains open until ventricular systole closes it forcibly, resulting in an increase in S1 intensity. Late in the course of the disease, the valve may become so stenotic that it no longer opens or closes, reducing the intensity of S1.
(4) Increased intensity of the P2 component of the S2. The P2 component of the S2 is usually increased in intensity if pulmonary hypertension has developed.
(5) Opening snap. An opening snap is heard following the S2 as the stenotic valve is forced open in diastole by the high left atrial filling pressure. The higher the pressure, the sooner the mitral valve opens. Thus, a short interval (<0.10 second in duration) indicates relatively high left atrial pressure and severe stenosis.
(6) Diastolic rumble. The murmur of mitral stenosis is a low-pitched apical rumble, which begins after the opening snap. If the patient is in sinus rhythm, atrial systole produces a presystolic accentuation of this murmur.
(7) Sternal lift. Enlargement of the right ventricle as a result of pulmonary hypertension produces a systolic lift of the sternum.
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(8) Other symptoms. Neck vein distention, edema, hepatic enlargement, and ascites may be present if right ventricular failure occurs.
4. Laboratory diagnosis
a. Electrocardiography. The ECG may show atrial fibrillation as well as signs of left atrial enlargement and right ventricular hypertrophy.
b. Chest radiography
(1) Straightening of the left heart border and a double density along the right heart border (formed by the right and left atria) occur as a result of left atrial enlargement.
(2) Signs of pulmonary venous hypertension, including an increase in pulmonary vascular markings and Kerley's lines, are likely to be present.
(3) When pulmonary hypertension leads to right ventricular enlargement, the lateral view shows a loss of the retrosternal airspace.
c. Echocardiography usually provides excellent images of the mitral valve.
(1) The echocardiogram shows reduction in the excursion of the valve leaflets and thickening of the valve. Two-dimensional echocardiography can be used to visualize and measure the residual mitral valve orifice. Invariably, left atrial enlargement is present.
(2) Doppler examination of the mitral valve may also help to quantify the severity of the stenosis.
5. Therapy
a. Medical therapy is reserved for patients with mild-to-moderate symptoms of left-sided failure.
(1) Diuretics. The mainstay of treatment, these agents are used to control pulmonary congestion and to limit dyspnea and orthopnea.
(2) Digitalis. Because left ventricular muscle function usually is normal in mitral stenosis, the use of digitalis is of little benefit to patients in sinus rhythm. In patients in atrial fibrillation, however, digitalis is used to slow ventricular rate. A rapid ventricular rate in mitral stenosis shortens diastole, thereby reducing left ventricular filling, which, in turn, further increases left atrial pressure and reduces cardiac output. خ²-Blockers and diltiazem or verapamil may be added to digoxin if further heart rate control is necessary.
(3) Anticoagulants. Patients with mitral stenosis and coexistent atrial fibrillation have a high incidence of systemic embolism. In such patients, anticoagulation therapy (e.g., with warfarin) usually is indicated.
b. Balloon valvuloplasty. Unlike balloon valvuloplasty for aortic stenosis, balloon valvuloplasty for mitral stenosis can offer effective long-term improvement.
(1) Valvuloplasty for mitral stenosis produces a commissurotomy similar to that produced at open heart surgery. During balloon mitral valvuloplasty, transseptal catheterization of the interatrial septum is performed, allowing passage of the balloon catheter from the right atrium to the left atrium. From the left atrium, the balloon catheter is advanced to the mitral valve and is inflated.
(2) Echocardiography is essential in predicting immediate and long-term success. Factors influencing the feasibility and success of valvuloplasty include the degrees of mitral regurgitation, valvular thickening, calcification, and mobility, and the degree of subvalvular involvement.
c. Surgical therapy is effective in relieving the symptoms of mitral stenosis and in prolonging life in symptomatic patients. Surgery should be performed prior to the development of pulmonary hypertension, which increases surgical risk. However, if pulmonary hypertension is present and surgery is successful, pulmonary hypertension usually regresses postoperatively.




C. Aortic regurgitation (or aortic insufficiency)
1. Etiology
a. Idiopathic aortic root dilation. Aortic root dilation, a common cause of aortic regurgitation, occurs more frequently in patients with hypertension but correlates best with increasing age. It is also seen more frequently in patients with bicuspid aortic valves.
b. Rheumatic heart disease. Aortic insufficiency usually is present to some degree in most cases of rheumatic heart disease. Mitral stenosis usually predominates, but occasionally aortic insufficiency is the most severe manifestation of rheumatic heart disease.
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c. Infective endocarditis. Infection of the aortic valve may lead to perforation or partial destruction of one or more aortic leaflets, producing aortic insufficiency.
d. Marfan syndrome may produce aortic insufficiency in two ways.
(1) Proximal root dilation. The extreme expansion of the proximal aortic root seen in Marfan syndrome may produce aortic insufficiency.
(2) Aortic root dissection. The advanced cystic medial necrosis present in Marfan syndrome may lead to an intimal tear and dissection of the aorta. If the dissection involves the proximal aortic root, the supporting structures of the aortic valve are disrupted, and the valve is rendered incompetent.
e. Aortic dissection. Any cause of aortic dissection other than Marfan syndrome may lead to aortic insufficiency.
f. Syphilis may produce aortitis, which may extend to the aortic valve and produce aortic incompetence.
g. Collagen vascular disease. Systemic lupus erythematosus (SLE) and ankylosing spondylitis may cause aortic insufficiency.
2. Pathophysiology
a. A portion of the left ventricular stroke volume ejected during systole regurgitates into the left ventricle during diastole. If no compensation occurs, left ventricular forward output decreases. However, chronic regurgitation of blood into the left ventricle produces eccentric cardiac hypertrophy and an increase in end-diastolic volume. The stroke volume (end-diastolic volume minus end-systolic volume) therefore increases, helping to compensate for the volume that is regurgitated. The increase in total stroke volume leads to an increase in pulse pressure and increased systolic pressure. The additional development of concentric hypertrophy compensates this second type of overload. The additional volume and pressure that the left ventricle must generate eventually lead to left ventricular dysfunction and CHF.
b. An additional pathophysiologic consequence of aortic insufficiency is a reduction in systemic diastolic blood pressure.
3. Clinical features
a. Symptoms
(1) Left ventricular failure
(a) Chronic aortic insufficiency may cause left ventricular dysfunction, leading to symptoms of dyspnea, orthopnea, and paroxysmal nocturnal dyspnea.
(b) In acute aortic insufficiency, normal muscle function may coexist with heart failure. In this circumstance, reduced forward output and elevated left ventricular filling pressure occur prior to compensatory left ventricular enlargement.
(2) Syncope. Reduction in diastolic systemic arterial pressure produces a reduction in mean arterial pressure. If the mean arterial pressure is reduced significantly, cerebral perfusion is compromised, and syncope may occur.
(3) Angina occurs less commonly in aortic insufficiency than in aortic stenosis. The cause of angina in aortic insufficiency is reduced coronary blood flow. Coronary blood flow occurs primarily in diastole and is driven by the aortic diastolic blood pressure. This driving pressure is reduced in aortic insufficiency, in turn reducing coronary blood flow.
b. Physical signs
(1) Left ventricular impulse. The PMI is hyperdynamic and is displaced downward and to the left as a result of left ventricular enlargement.
(2) Diastolic murmur. The murmur of aortic insufficiency is a high-pitched, diastolic blowing murmur heard along the left sternal border. Often the murmur is heard best when the patient is sitting up and leaning forward.
(3) Austin Flint murmur. A low-pitched diastolic rumble similar to that heard in mitral stenosis may be present in patients with aortic insufficiency. The Austin Flint murmur usually indicates moderate-to-severe insufficiency. The murmur is believed to be caused by reverberation of the regurgitant flow against the mitral valve, although the exact mechanism is unclear.
(4) Total stroke volume and consequently, pulse pressure, increases in chronic aortic insufficiency. The increased stroke volume and pulse pressure lead to many physical signs, some of which are included in the following.
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(a) Corrigan's pulse. The carotid pulse has a rapid rise and full upstroke with a rapid fall in diastole.
(b) Hill's sign refers to a disproportionate increase of systolic blood pressure (i.e., >30 mm Hg) when measured in the leg, as compared with the systolic blood pressure measured in the arm. This sign suggests severe aortic insufficiency.
(c) Pistol-shot femoral pulses. Auscultation over the femoral arteries reveals a pulse that sounds like a pistol shot.
(d) Duroziez's sign. A stethoscope is placed over the femoral artery with enough pressure to produce a systolic bruit. The concomitant occurrence of a diastolic bruit constitutes Duroziez's sign.
(e) de Musset's sign refers to a bobbing movement of the head caused by the increased stroke volume and pulse pressure.
(f) Quincke's pulse is systolic blushing and diastolic blanching of the nail bed when gentle pressure is placed on the nail.
(5) Acute aortic insufficiency. The preceding signs are usually absent in acute aortic insufficiency because compensatory increases in end-diastolic volume and stroke volume have not yet occurred. In fact, the clinical picture of acute severe aortic insufficiency is remarkably bland. The apical impulse is not enlarged. S1 is soft because increased left ventricular end-diastolic pressure closes the mitral valve before systole. This finding marks a poor prognosis for patients treated without valve replacement.
4. Diagnosis
a. Electrocardiography. The ECG usually shows left ventricular hypertrophy. In endocarditis, a prolonged PR interval may indicate abscess formation involving the conduction system.
b. Chest radiography. Unless the aortic insufficiency is mild or acute, cardiac enlargement is usually present, and often the proximal aorta is dilated. The absence of cardiac enlargement is evidence against the diagnosis of severe chronic aortic insufficiency.
c. Echocardiography. Evidence of an enlarged left ventricular cavity is usually present in aortic insufficiency. Frequently, diastolic vibration of the mitral valve is present, produced by the regurgitant flow striking the valve. Doppler examination of the aortic outflow tract reveals abnormal diastolic flow from the aorta to the left ventricle, which may be analyzed quantitatively.
d. Cardiac catheterization. Aortography may be performed at the time of cardiac catheterization. This is useful if noninvasive testing is not diagnostic or discordant with clinical findings.
5. Therapy. If aortic insufficiency is severe, eventual aortic valve replacement is necessary.
a. Timing of surgery is difficult, however, because the lesion may be tolerated for several years. Careful follow-up is required to detect early signs of decompensation; at this time, valve replacement is advisable. In most cases, valve replacement should be performed before the left ventricular echocardiographic end-systolic dimension exceeds 55 mm and the ejection fraction falls below 55%.
b. For those who do not yet meet the criteria for surgery, vasodilator therapy with dihydropyridine calcium channel blockers or ACE inhibitors can improve hemodynamics and may delay onset of left ventricular dysfunction and the need for surgery.




D. Mitral regurgitation (or mitral insufficiency)
1. Etiology
a. Mitral valve prolapse is characterized by redundant mitral valve leaflets or chordae that permit systolic prolapse of the mitral valve into the left atrium with resultant mitral regurgitation.
(1) This syndrome usually is benign, but in some cases it may be associated with significant mitral regurgitation. Additional complications include atypical chest pain, cardiac arrhythmias, and an increased risk of endocarditis. Most clinically important sequelae occur in those patients whose mitral valves are clearly thickened and echocardiographically abnormal.
(2) A midsystolic click and a late systolic murmur typically are heard on physical examination.
b. Coronary artery disease may lead to ischemia or infarction of the papillary muscles to which the mitral valve is tethered, thereby producing mitral incompetence.
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c. Rheumatic heart disease. Scarring and retraction of the mitral leaflets as a result of rheumatic heart disease cause mitral regurgitation.
d. Ruptured chordae tendineae. Spontaneous rupture of the chordae tendineae may occur in otherwise healthy individuals. Chordal rupture permits prolapse of a portion of a mitral valve leaflet into the left atrium, rendering the valve incompetent.
e. Infective endocarditis. Infection of the mitral valve may cause its destruction with subsequent regurgitation.
2. Pathophysiology. Mitral regurgitation permits a portion of the left ventricular stroke volume to be pumped backward into the left atrium instead of forward into the aorta, resulting in increased left atrial pressure and decreased forward cardiac output. Preload is increased by the volume overload, and afterload is initially decreased as the left ventricle empties a portion of its contents into the relatively (i.e., compared with the aorta) low-pressure left atrium. This augments ejection performance and helps compensate for the regurgitation.
a. Initially, compliance of the left atrium is low, and the regurgitant volume produces high left atrial pressure with resultant congestive symptoms.
b. With time, the left atrial compliance and volume increase, allowing accommodation of the regurgitant volume at more physiologic filling pressures.
c. The development of left ventricular eccentric cardiac hypertrophy restores forward stroke volume.
d. After a prolonged period of compensation, left ventricular muscle dysfunction eventually occurs, resulting in a fall in ejection fraction from supranormal to normal or even subnormal values.
3. Clinical features
a. Symptoms. Characteristics include those of left ventricular failure (i.e., dyspnea, orthopnea, and paroxysmal nocturnal dyspnea).
(1) If mitral regurgitation is severe and chronic, pulmonary hypertension and symptoms of right-sided failure also may occur.
(2) Patients in atrial fibrillation may experience symptoms of systemic embolization. The risk of embolization appears to be less in patients with mitral regurgitation than in those with mitral stenosis, although this is debatable.
b. Physical signs
(1) Left ventricular impulse. As with aortic regurgitation, the PMI is hyperdynamic and displaced downward and to the left.
(2) Murmur. The murmur of mitral regurgitation is a holosystolic apical murmur that radiates to the axilla. It does not vary in intensity with variation in R-R interval.
(3) An S3 usually is heard in mitral regurgitation and may occur even in the absence of overt heart failure. The S3 is caused by the rapid filling of the left ventricle by the large volume of blood accumulated in the left atrium during systole.
4. Diagnosis
a. Electrocardiography. The ECG shows signs of left ventricular hypertrophy and left atrial enlargement.
b. Chest radiography shows cardiac enlargement. Vascular congestion indicates heart failure.
c. Echocardiography
(1) In cases of a ruptured chorda or mitral valve prolapse, the mitral valve can be seen extending into the left atrium during systole.
(2) When the mitral valve has been damaged by endocarditis, vegetations on the mitral leaflets frequently are demonstrated. Transesophageal echocardiography is better than transthoracic echocardiography for detecting vegetations.
(3) Regardless of the cause of the mitral regurgitation, left atrial and left ventricular enlargement occur if the condition is both chronic and severe.
(4) Doppler examination reveals abnormal systolic flow from the left ventricle into the left atrium. Quantitative doppler techniques can accurately assess the regurgitant orifice area and the regurgitant volume, both of which are important in determining severity.
d. Cardiac catheterization. Right-heart catheterization yields a pulmonary capillary wedge tracing that often displays a large v wave representative of the systolic volume overload on
P.25the left atrium. Left ventriculography demonstrates systolic regurgitation of contrast material into the left atrium.
5. Therapy
a. Medical treatment. The goal of medical therapy is to relieve symptoms by increasing forward cardiac output and reducing pulmonary venous hypertension.
(1) Digitalis. When atrial fibrillation occurs, digitalis is useful in controlling heart rate. In chronic mitral regurgitation with muscle dysfunction, this agent may be useful in increasing the inotropic state. In cases of acute mitral regurgitation when no inotropic deficit exists, it is not indicated.
(2) Diuretics are used to reduce central volume overload, which in turn reduces pulmonary venous hypertension and congestion.
(3) Vasodilators. Arteriolar vasodilators are particularly useful in managing acute mitral regurgitation. These agents reduce resistance to aortic outflow, thereby preferentially increasing forward output while reducing the amount of regurgitation. Vasodilators also reduce left ventricular size, which helps to reestablish mitral competence.
(4) Anticoagulants. Patients with mitral regurgitation and atrial fibrillation are at some risk for systemic embolism; therefore, anticoagulants usually are indicated.
b. Surgical treatment. Mitral valve replacement or repair is indicated for chronic mitral regurgitation, even if symptoms are mild, if there is evidence of ventricular dysfunction.
(1) Valve replacement must be performed prior to the onset of significant muscle dysfunction, which limits the success of operative intervention. To help ensure preservation of ventricular function, surgery should occur before the ejection fraction falls below 60% or the end-systolic dimension exceeds 40 mm.
(2) Valve repair offers several advantages over replacement, including eliminating the introduction of a prosthesis and decreasing the need for anticoagulation therapy. Furthermore, repairing, rather than replacing, the valve helps preserve left ventricular function because the mitral valve apparatus, which plays an important role in ventricular contraction is preserved.








E. Tricuspid regurgitation
1. Etiology
a. Infective endocarditis. In drug abusers who inject drugs under septic conditions, infective endocarditis is a common cause of tricuspid regurgitation.
b. Right ventricular failure. Sustained pressure or volume overload on the right ventricle leads to right ventricular dilation and improper alignment of the papillary muscles, which produces tricuspid regurgitation.
c. Rheumatic heart disease. In rheumatic heart disease, tricuspid regurgitation may occur, secondary to right ventricular pressure overload from left-sided valvular lesions. Tricuspid regurgitation also may occur as a result of primary rheumatic involvement of the tricuspid valve.
2. Pathophysiology. During systole, the dysfunctioning tricuspid valve allows blood to flow backward into the right atrium, leading to systemic venous congestion and venous hypertension.
3. Clinical features
a. Symptoms. Right-sided failure (i.e., edema, ascites) occurs. In severe and acute cases, hepatic congestion may be sufficiently extensive to produce right upper quadrant pain. Passive hepatic congestion also may lead to hepatocellular damage and jaundice.
b. Physical signs
(1) Right ventricular lift. The enlarged right ventricle may be palpated as a systolic lift of the sternum.
(2) Murmur. A holosystolic murmur that increases with inspiration is heard along the left sternal border.
(3) Jugular venous pulsation. A large v wave is seen in jugular veins during systole.
(4) Pulsatile liver. Systolic expansion of the liver frequently is present.
4. Diagnosis
a. Chest radiography shows right ventricular enlargement as an obliteration of the retrosternal airspace on the lateral view.
P.26
b. Echocardiography demonstrates enlargement of the right atrium and right ventricle. Doppler examination is highly effective in demonstrating tricuspid regurgitation.
5. Therapy. Left-sided failure frequently is the cause of right-sided failure and tricuspid regurgitation. Effective treatment of left-sided failure reduces right ventricular pressure overload, which may decrease right ventricular size, thereby restoring valvular competence. If tricuspid regurgitation is caused by organic valvular disease, surgical repair or replacement of the tricuspid valve may be necessary.