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 “3†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,†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.
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 “3†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,†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.
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