General Principles of Treatment of Congenital Heart Disease

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Chapter 428 General Principles of Treatment of Congenital Heart Disease

Most patients who have mild congenital heart disease require no treatment. The parents and child should be made aware that a normal life is expected and that no restriction of the child’s activities is necessary. Overprotective parents may use the presence of a mild congenital heart lesion or even a functional heart murmur as a means to exert excessive control over their child’s activities. Although fears may not be expressed overtly, the child may become anxious regarding early death or debilitation, especially when an adult member of the family acquires unrelated symptomatic heart disease. The family may have an unexpressed fear of sudden death, and the rarity of this manifestation should be emphasized in discussions directed at improving their understanding of the child’s congenital heart defect. The difference between congenital heart disease and degenerative coronary disease in adults should be emphasized. General health maintenance, including a well-balanced, “heart-healthy” diet; aerobic exercise; and avoidance of smoking, should be encouraged.

Even patients with moderate to severe heart disease need not be markedly restricted in physical activity. Physical education should be modified appropriately to the child’s capacity to participate. The extent of such modification can generally be determined best by formal exercise testing. Competitive sports for many of these patients is discouraged, but decisions are usually made on an individual basis. Patients with severe heart disease and decreased exercise tolerance usually tend to limit their own activities. Dyspnea, headache, and fatigability in cyanotic patients may be a sign of increasing hypoxemia and may require limitation of activity in those for whom specific medical or surgical treatment is not available. Routine immunizations should be given, with the inclusion of influenza vaccine during the appropriate season; patients who might be considered candidates for heart or heart-lung transplantation should not receive live-virus vaccinations just before transplantation.

Bacterial infections should be treated vigorously, but the presence of congenital heart disease is not an appropriate reason to use antibiotics indiscriminately. Prophylaxis against infective endocarditis should be carried out during dental procedures for appropriate patients. The American Heart Association has recently significantly revised these recommendations, with most patients no longer requiring routine prophylaxis (Chapter 431).

Cyanotic patients need to be monitored for a multitude of noncardiac manifestations of oxygen deficiency (Table 428-1). Treatment of iron deficiency anemia is important in cyanotic patients, who will show improved exercise tolerance and general well-being with adequate hemoglobin levels. These patients should also be carefully observed for excessive polycythemia. Cyanotic patients should avoid situations in which dehydration may occur, which leads to increased viscosity and increases the risk of stroke. Diuretics may need to be decreased or temporarily discontinued during episodes of acute gastroenteritis. High altitudes and sudden changes in the thermal environment should also be avoided. Phlebotomy with partial exchange transfusion is carried out only in symptomatic patients with severe polycythemia (usually those hematocrit >65%). Patients with moderate to severe forms of congenital heart disease or a history of rhythm disturbance should be carefully monitored during anesthesia for even routine surgical procedures. Consultation with an anesthesiologist experienced in the care of children with congenital heart disease is encouraged. Women with nonrepaired severe congenital heart disease should be counseled on the risks associated with childbearing and on the use of contraceptives and tubal ligation. Pregnancy may be dangerous for patients with chronic cyanosis or pulmonary arterial hypertension. Women with mild to moderate heart disease and many of those who have had corrective surgery can have normal pregnancies, although those with residual hemodynamic derangements or with systemic right ventricles should optimally be followed by a high-risk perinatologist and a cardiologist with expertise in caring for adults with congenital heart disease.

Table 428-1 EXTRACARDIAC COMPLICATIONS OF CYANOTIC CONGENITAL HEART DISEASE AND EISENMENGER PHYSIOLOGY

PROBLEM	ETIOLOGY	THERAPY
Polycythemia	Persistent hypoxia	Phlebotomy
Relative anemia	Nutritional deficiency	Iron replacement
CNS abscess	Right-to-left shunting	Antibiotics, drainage
CNS thromboembolic stroke	Right-to-left shunting or polycythemia	Phlebotomy
Low-grade DIC, thrombocytopenia	Polycythemia	None for DIC unless bleeding, then phlebotomy
Hemoptysis	Pulmonary infarct, thrombosis, or rupture of pulmonary artery plexiform lesion	Embolization
Gum disease	Polycythemia, gingivitis, bleeding	Dental hygiene
Gout	Polycythemia, diuretic agent	Allopurinol
Arthritis, clubbing	Hypoxic arthropathy	None
Pregnancy complications: abortion, fetal growth retardation, prematurity increase, maternal illness	Poor placental perfusion, poor ability to increase cardiac output	Bed rest, pregnancy prevention counseling
Infections	Associated asplenia, DiGeorge syndrome, endocarditis	Antibiotics
Infections	Fatal RSV pneumonia with pulmonary hypertension	Ribavirin; RSV immunoglobulin (prevention)
Failure to thrive	Increased oxygen consumption, decreased nutrient intake	Treat heart failure; correct defect early; increase caloric intake
Psychosocial adjustment	Limited activity, cyanotic appearance, chronic disease, multiple hospitalizations	Counseling

CNS, central nervous system; DIC, disseminated intravascular coagulation; RSV, respiratory syncytial virus.

Postoperative Management

After successful open heart surgery, the severity of the congenital heart defect, the age and condition (nutritional status) of the patient before surgery, the events in the operating room, and the quality of the postoperative care influence the patient’s course. Intraoperative factors that influence survival and that should be noted when a patient returns from the operating room include the duration of cardiopulmonary bypass, the duration of aortic cross-clamping (the time during which the heart is not being perfused), and the duration of profound hypothermia (used in some newborns: the period during which the entire body is not being perfused).

Immediate postoperative care should be provided in an intensive care unit staffed by a team of physicians, nurses, and technicians experienced with the unique problems encountered after open heart surgery in childhood. In most major centers, this occurs in a dedicated pediatric cardiovascular intensive care unit. Preparation for postoperative monitoring begins in the operating room, where the anesthesiologist or surgeon places an arterial catheter to allow direct arterial pressure measurements and arterial sampling for blood gas determination. A central venous catheter is also placed for measuring central venous pressure and for infusions of cardioactive medications. In more complex cases, right or left atrial or pulmonary artery catheters may be inserted directly into these cardiac structures and used for pressure monitoring purposes. Flow-directed thermodilution monitoring (Swan-Ganz) catheters are sometimes used for monitoring pulmonary capillary wedge pressure and the cardiac index, although this modality is not commonly used in children. Temporary pacing wires are placed on the atrium or ventricle, or both, in case temporary postoperative heart block occurs. Transcutaneous oximetry provides for continuous monitoring of arterial oxygen saturation.

Functional failure of one organ system may cause profound physiologic and biochemical changes in another. Respiratory insufficiency, for example, leads to hypoxia, hypercapnia and acidosis, which, in turn, compromise cardiac, vascular, and renal function. The latter problems cannot be managed successfully until adequate ventilation is re-established. Thus, it is essential that the primary source of each postoperative problem be identified and treated.

Respiratory failure is a serious postoperative complication encountered after open heart surgery. Cardiopulmonary bypass carried out in the presence of pulmonary congestion results in decreased lung compliance, copious tracheal and bronchial secretions, atelectasis, and increased breathing effort. Because fatigue and, subsequently, hypoventilation and acidosis may rapidly ensue, mechanical positive pressure endotracheal ventilation may be continued after open heart surgery for a minimum of several hours in relatively stable patients and for up to 2-3 days or longer in severely ill patients, especially infants. Patients with certain congenital heart lesions, particularly those with DiGeorge syndrome, may also have airway abnormalities (micrognathia, tracheomalacia, bronchomalacia) that can make extubation more difficult.

The electrocardiogram should be monitored continuously during the postoperative period. A change in heart rate, even without arrhythmia, may be the first indication of a serious complication such as hemorrhage, hypothermia, hypoventilation, or heart failure. Cardiac rhythm disorders must be diagnosed quickly because a prolonged untreated arrhythmia may add a severe hemodynamic burden to the heart in the critical early postoperative period (Chapter 429). Injury to the heart’s conduction system during surgery can result in postoperative complete heart block. This complication is usually temporary and is treated with surgically placed pacing wires that can later be removed. Occasionally, complete heart block is permanent. If heart block persists beyond 10-14 days postoperatively, insertion of a permanent pacemaker is required. Tachyarrhythmias are a common problem in postoperative patients. Junctional ectopic tachycardia (JET) can be a particularly troublesome rhythm to manage (Chapter 429), although it usually responds to intravenous amiodarone.

Heart failure with poor cardiac output after cardiac surgery may be secondary to respiratory failure, serious arrhythmias, myocardial injury, blood loss, hypovolemia, a significant residual hemodynamic abnormality, or any combination of these factors. Treatment specific to the cause should be instituted. Catecholamines, phosphodiesterase inhibitors, nitroprusside and other afterload-reducing agents, and diuretics are the cardioactive agents most often used in patients with myocardial dysfunction in the early postoperative period (Chapter 436). Postoperative pulmonary hypertension can be managed with hyperventilation and inhaled nitric oxide. In patients who are unresponsive to standard pharmacologic treatment, various ventricular assist devices are available, depending on the patient’s size. If pulmonary function is adequate, a left ventricular assist device (LVAD) may be used. If pulmonary function is inadequate, extracorporeal membrane oxygenation (ECMO) may be used. These extraordinary measures are helpful in maintaining the circulation until cardiac function improves, usually within 2-3 days. They have also been used with moderate success as a bridge to transplantation in patients with severe nonremitting postoperative cardiac failure.

Acidosis secondary to low cardiac output, renal failure, or hypovolemia must be prevented or if present, promptly corrected. Serial monitoring of arterial blood gases and lactate concentrations is performed. An arterial pH <7.3 may result in a decrease in cardiac output with an increase in lactic acid production and may be the forerunner of arrhythmias or cardiac arrest.

Renal function may be compromised by congestive heart failure and further impaired by prolonged cardiopulmonary bypass. Blood and fluid replacement, cardiac inotropic agents, and vasodilators will usually re-establish normal urine flow in patients with hypovolemia or cardiac failure. Renal failure secondary to tubular injury may require temporary peritoneal or hemodialysis or hemofiltration.

Neurologic abnormalities can develop after cardiopulmonary bypass, especially in the neonatal period. Seizures may occur when the patient awakens from sedation and can usually be controlled with anticonvulsant medications. In the absence of other neurologic signs, self-limited isolated seizures in the immediate postoperative period usually carry a good long-term prognosis. Thromboembolism and stroke are rarer but serious complications of open heart surgery. In the long term, both subtle and more substantial learning disabilities may develop. Patients who have undergone surgery entailing the use of cardiopulmonary bypass, especially in the newborn period, should be watched carefully during their early school years for signs of mild to moderate learning disabilities, which are often amenable to early remedial intervention. The risk is higher in patients who have undergone repair using hypothermic total circulatory arrest than in those where systemic blood flow is maintained using cardiopulmonary bypass.

The postpericardiotomy syndrome may occur toward the end of the 1st postoperative week or may sometimes be delayed until weeks or months after surgery. This febrile illness is characterized by fever, decreased appetite, listlessness, nausea, and vomiting. Chest pain is not always present, so a high index of suspicion should be maintained in any recently postoperative patient. Echocardiography is diagnostic. In most instances, the postpericardiotomy syndrome is self-limited; however, when pericardial fluid accumulates rapidly, the potential danger of cardiac tamponade should be recognized (Chapter 434). Rarely, arrhythmias may also occur. Symptomatic patients usually respond to salicylates or indomethacin and bed rest. Occasionally, steroid therapy or pericardiocentesis is required. Late recurrences can occur but are less usual.

Hemolysis of mechanical origin is seen, although rarely, after repair of certain cardiac defects, for example, atrioventricular septal defects (AVSDs), or after the insertion of a mechanical prosthetic valve. It is due to unusual turbulence of blood at increased pressure. Reoperation may be necessary in rare patients with severe and progressive hemolysis who require frequent blood transfusions, but in most instances the problem slowly regresses.

Infection is another potentially serious postoperative problem. Patients usually receive a broad-spectrum antibiotic for the initial postoperative period. Potential sites of infection include the lungs (generally related to postoperative atelectasis), the subcutaneous tissues at the incision site, the sternum, and the urinary tract (especially after an indwelling catheter has been in place). Sepsis with infective endocarditis is an infrequent complication, and can be difficult to manage, especially if prosthetic material was placed at the time of surgery (Chapter 431).

Long-Term Management

Patients who have undergone surgery for congenital heart disease can be divided into several major categories: (1) lesions for which total repair has been achieved; (2) lesions for which both anatomic and physiologic correction has been achieved; and (3) lesions for which only palliation, albeit potentially long-term, has been achieved. There is some disagreement among cardiologists as to exactly which categories a particular congenital heart lesion might fall, and to some degree every case should be considered individually. Many argue that only for isolated patent ductus arteriosus is total repair really achieved, with no requirement for long-term follow-up. Patients who are able to undergo anatomic and physiologic correction include many of the left-to-right shunt lesions (atrial and ventricular septal defects) and milder forms of obstructive lesions (e.g., valvar pulmonic stenosis, some forms of valvar aortic stenosis, and coarctation of the aorta), and some forms of cyanotic heart disease, for example, uncomplicated tetralogy of Fallot and simple transposition of the great arteries. These patients usually have achieved total or near-total physiologic correction of their lesion; however, they are still at some risk of long-term sequelae, including late heart failure or arrhythmia, or recurrence of a significant physiologic abnormality (e.g., recoarctation of the aorta, worsening mitral regurgitation in patients with AVSDs, or long-standing pulmonary regurgitation in patients with tetralogy of Fallot repaired with a transannular patch). These patients require regular follow-up with a pediatric cardiologist (and when old enough, with an adult congenital heart disease specialist [Chapter 428.1]), however, their long-term prognosis is generally very good. Patients with more complex lesions, such as those with single ventricle physiology, are at much higher risk of long-term sequelae and require even closer follow-up. These patients, particularly those who have undergone the Fontan procedure, are at risk long-term for arrhythmia, thrombosis, protein losing enteropathy, end-organ (especially hepatic) dysfunction, and heart failure. Some may eventually require cardiac transplantation.

Physical limitations are variable, ranging from minimal to none in patients with physiologic correction, to mild to moderate in patients with palliative procedures. The extent to which a patient should be allowed to participate in athletics, both recreational and competitive, can best be determined by the cardiologist, often with the assistance of the data that can be derived from cardiopulmonary exercise testing (Chapter 417.5).

Long-term morbidities affecting neurologic function and behavior are influenced by many factors, including the effects of any genetic alterations on the developing central nervous system. Data suggest a greater role for prenatal central nervous system abnormalities (anatomic or secondary to alterations in cerebral blood flow or oxygenation) than previously suspected; these include microcephaly, cerebral atrophy, altered cerebral biochemistry (lactate, choline, N-acetylaspartate) average diffusivity, and fractional anisotropy of white matter tracts. Chronic hypoxemia and failure to thrive also may influence the developing brain, and there is evidence that the type of intervention required (cardiopulmonary bypass, hypothermic total circulatory arrest, catheter-based therapy) plays a substantial role. In general, in the absence of a significant genetic syndrome or major perioperative complication, most children function at a fairly high level after repair of congenital heart defects and are able to attend regular school. Group mean scores on standard cognitive tests are not different from the general population; however, some areas appear to be more at risk than others, including certain aspects of motor function, speech, visual-motor tracking, and phonological awareness. Awareness of these potential issues is critical to obtaining prompt remedial assistance if a child is found to be struggling in school.

Bibliography

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Bjarnason-Wehrens B, Dordel S, Schickendantz S, et al. Motor development in children with congenital cardiac diseases compared to their healthy peers. Cardiol Young. 2007;17:487-498.

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428.1 Congenital Heart Disease in Adults

Michael G. Earing

The advent of cardiac surgical procedures such as ligation of patent ductus arteriosus, resection of coarctation of aorta, and the Blalock-Taussig shunt, as well as advances in diagnostic, interventional, and critical care skills have resulted in survival of approximately 90% of children with congenital heart disease to adulthood. More adults than children are living with congenital heart disease in the USA, with a 5% increase every year.

Long-Term Medical Considerations

About 25% of adults with congenital heart disease have a mild form that has allowed them to survive into adulthood without surgical or interventional cardiac catheterization. The most common lesions in this category include mild aortic valve stenosis (usually in setting of bicuspid aortic valve), small restrictive ventricular septal defects, mild pulmonary valve stenosis, and mitral valve prolapse (Table 428-2). These patients need less frequent follow-up to assess for progression of disease and to identify associated complications. The majority of adults with congenital heart disease living in the USA are patients who have had previous intervention (Table 428-3). Although the majority of children who undergo surgical intervention will survive to adulthood, with few exceptions, “total correction” is not the rule. The few exceptions include patent ductus arteriosus, ventricular septal defects, and atrial septal defects; this is true only if they are closed early before the development of irreversible pulmonary vascular changes and no residual lesions exist. Because adult patients with congenital heart disease are surviving longer than ever, it is becoming increasingly apparent that even the simplest lesions can be associated with long-term complications. These long-term complications include both cardiac and noncardiac problems (Tables 428-4 and 428-5, Fig. 428-1). Cardiac complications include arrhythmias and conduction defects, ventricular dysfunction, residual shunts, valvular lesions (regurgitation and stenosis), hypertension, and aneurysms. Noncardiac sequelae include developmental abnormalities such as developmental delay, somatic abnormalities such as facial dysmorphism (cleft palate/lip), central nervous abnormalities such as seizure disorders from previous thromboembolic events or cerebrovascular accidents, disturbances of the senses such as hearing loss or vision loss, and pulmonary sequelae such as both restrictive and obstructive lung disease. Psychosocial problems involving employment, life and health insurance, participation in sports, sexual activity, and contraception are common. As result of these long-term complications, the majority of adults with congenital heart disease need lifelong follow-up.

Table 428-3 MOST COMMON CONGENITAL HEART DEFECTS SURVIVING TO ADULTHOOD AFTER SURGERY OR INTERVENTIONAL CATHETERIZATION

Aortic valve disease following balloon valvuloplasty or surgical valvotomy

Pulmonary valve stenosis following balloon valvuloplasty or surgical valvotomy

Tetralogy of Fallot

Ventricular septal defect

Completer atrioventricular canal

Transposition of the great arteries

Coarctation of the aorta

Complex single ventricles after the modified Fontan procedure

Table 428-4 RISKS IN ADULTS WHO HAVE CONGENITAL HEART DISEASE

Rhythm disorder

Supraventricular tachycardia

Right bundle branch block

Heart block

Ventricular tachycardia

Sudden death

Coarctation of aorta

Essential hypertension

Recoarctation

Aneurysm formation

Residual lesions (shunts)

Supravalvular stenosis

Valvular insufficiency

ASD, atrial septal defect; PDA, patent ductus arteriosus; SBE, subacute bacterial endocarditis; VSD, ventricular septal defect.

Table 428-5 LESION SPECIFIC RISKS OF MATERNAL AND NEONATAL COMPLICATIONS OF PREGNANCY

No additional risk	Small septal defects
	Surgically closed ASD, VSD, PDA
	Mild to moderate aortic regurgitation
	Mild to moderate pulmonary stenosis
Slightly increased risk	Postoperative repair of tetralogy of Fallot
Slightly increased risk	Transposition of the great arteries, s/p arterial switch procedure
Moderate risk	Transposition of the great arteries, s/p atrial switch procedure
	Congenitally corrected transposition of the great arteries
	Single ventricle physiology, s/p Fontan procedure
Severe risk	Cyanotic congenital heart disease, unoperated or palliated
	Marfan syndrome
	Prosthetic valves
	Obstructive lesions including coarctation
Pregnancy contraindicated	Severe pulmonary hypertension
	Severe obstructive lesions
	Marfan syndrome, aortic root >40 mm

ASD, atrial septal defect; PDA, patent ductus arteriosus; s/p, status post (after); VSD, ventricular septal defect.

Figure 428-1 Important issues that are crucial to address at time of transition.

(From Spence MS, Balaratnam MS, Gatzoulis MA: Clinical update: cyanotic adult congenital heart disease, Lancet 370:1530–1532, 2007, p 1531.)

Specific Lesions

Left-to-Right Shunts

If the shunt is large and nonrestrictive (allowing transmission of near systemic pressure to the pulmonary arteries), irreversible pulmonary vascular changes can occur, resulting in pulmonary hypertension at systemic levels with reversed or bidirectional shunting at the level of the defect (Eisenmenger syndrome) (Chapter 427.2).

Atrial Septal Defects (ASDs) (Chapter 420.1)

Although, most individuals with an ASD are diagnosed during childhood after a murmur is noted, a minority of patients present with symptoms for the first time as adults. Most patients are asymptomatic during the 1st and 2nd decades of life. In the 3rd decade, an increasing number of patients then develop exercise intolerance, palpitations due to atrial arrhythmias, and cardiac enlargement on chest x-ray. While survival into adulthood is the rule, life expectancy is not normal and there is significant long-term morbidity. After the age of 40 yr, the mortality rate increases by 6% per year, and more than 20% of patients will have developed atrial fibrillation. By age 60 yr, the number of patients with atrial fibrillation will have increased to more than 60%.

Late Outcome Following Closure of ASD

Most patients who have undergone early closure of a defect will have excellent long-term survival with low morbidity if repair is undertaken before age 25 yr. Older age of repair is associated with decreased late survival with an associated increased risk for the development of atrial arrhythmias, thromboembolic event, and pulmonary hypertension.

Long-term late complications and survival following transcatheter device closure remain unknown.

Ventricular Septal Defects (VSDs) (Chapter 420.6)

Although isolated VSDs are one of the most common forms of congenital heart disease, the diagnosis of a VSD in an adult is rare. The primary reason for this is that most patients with a hemodynamically significant VSD will have undergone repair in childhood or will have died earlier in life. As result, the spectrum of isolated VSD in adults is limited to (1) those with small restrictive defects, (2) those with Eisenmenger syndrome, and (3) those who had their defects closed in childhood.

For patients with small restrictive VSD, the long-term survival is excellent with estimated 25-yr survival of 96%. In addition, the long-term morbidity for patients with a restrictive VSD also appears to be low. Their clinical course is not completely benign. Reported long-term complications include endocarditis, progressive aortic regurgitation secondary to prolapse of aortic valve into the defect (highest risk is with supracristal type, but also can occur in setting of perimembranous defect), and the development of both right and left outflow tract obstruction from a double chamber right ventricle or a subaortic membrane.

For those patients who develop Eisenmenger syndrome, survival into the 3rd decade is common. With increasing age, the long-term complications of right heart failure, paradoxical emboli, and erythrocytosis usually result in progressive decline in survival, with an average age of death of 37 yr.

Adults with previous VSD closure, without pulmonary hypertension or residual defects, live a normal life expectancy.

Because patients with small VSDs are asymptomatic, these patients should be managed conservatively. Given the long-term risks, they do need intermittent follow-up for life to monitor for the development of late complications. The exception to this rule is patients with small supracristal or perimembranous VSD with associated prolapse of the aortic cusp into the defect resulting in progressive aortic regurgitation. These patients should be considered for surgical repair at the time of diagnosis to prevent progressive aortic valve damage.

Complete Atrioventricular Canal (Chapter 420.5)

The natural history for patients with complete AVSD is characterized by the early development of pulmonary vascular disease, leading to irreversible damage often by age 1 yr (especially in children with Down syndrome). Surgery needs to be undertaken early if it is to be successful. Thus, patients who present in adulthood can be categorized into two groups (1) those with Eisenmenger syndrome or (2) those who had their defects closed in childhood.

Overall, for those patients who underwent early repair before the development of pulmonary vascular disease, the long-term prognosis is good. The most common long-term complication is left AV valve regurgitation, with approximately 5-10% of patients requiring surgical revision for left AV valve repair or replacement during follow-up. The second most common long-term complication for this patient group is subaortic stenosis, occurring in up to 5% of patients after repair. Other long-term complications include residual atrial or ventricular level shunts, complete heart block, atrial and ventricular arrhythmias, and endocarditis.

For those patients who have developed Eisenmenger syndrome, all are symptomatic with exertional dyspnea, fatigue, palpitations, edema, and syncope. Survival is similar to other forms of Eisenmenger syndrome, with a mean age of death of 37 yr. Strong predictors for death in retrospective studies include syncope, age at presentation of symptoms, poor functional class, low oxygen saturation (<85%), serum creatinine, serum uric acid concentration, and Down syndrome.

Patients who underwent previous repair with significant left AV valve regurgitation causing symptoms, atrial arrhythmias, or deterioration in ventricular function should undergo elective repair or replacement. Those previously repaired patients who develop significant subaortic stenosis (defined as a peak cardiac catheterization or echo gradient of >50 mm Hg) should undergo surgical repair.

Patent Ductus Arteriosus (PDA) (Chapter 420.8)

A PDA is usually an isolated lesion in the adult patient. Like with VSDs, the size of the defect is the primary determinant of clinical course in the adult patient. These clinical courses can be grouped into 5 main categories: (1) silent PDAs, (2) small hemodynamically insignificant PDAs, (3) moderate size PDAs, (4) large PDAs, and (5) previously repaired PDAs.

A silent PDA is a tiny defect that cannot be heard by auscultation and is only detected by other nonclinical means such as echocardiography. Life expectancy is always normal in this population and the risk for endocarditis is extremely low.

Patients with a small PDA have an audible long-ejection or continuous murmur heard best at the left upper sternal border that radiates to the back. In addition, they have normal peripheral pulses. Because there is negligible left to right shunting these patients have normal left aorta (LA) and left ventricle (LV) size and normal pulmonary artery pressure by echocardiography and chest x-ray. These patients like those with silent PDAs are aysmptomatic and live a normal life expectancy. They have a higher risk for endocarditis.

Patients with moderate size PDAs may present during adulthood. These patients often will have wide, bouncy peripheral pulses and an audible continuous murmur. These patients all have significant volume overload and develop some degree of LA and LV enlargement and some degree of pulmonary hypertension. These patients are symptomatic with dyspnea, palpitations, and heart failure.

Patients with large PDAs typically present with signs of severe pulmonary hypertension and Eisenmenger syndrome. By adulthood, the continuous murmur is typically absent and there is differential cyanosis (lower extremity saturations lower than the right arm saturation). These patients have a similar prognosis as other patients with Eisenmenger syndrome.

Patients who underwent repair of a PDA prior to the development of pulmonary hypertension, have a normal life expectancy without restrictions.

All patients with clinical evidence of a PDA are at increased risk for endocarditis. As result, all PDAs except for small silent PDAs and those patients with severe irreversible pulmonary hypertension should be considered for closure. Catheter device closure is the preferred method in most centers today. Surgical closure is reserved for patients with PDAs too large for device closure or when the anatomy is distorted, such as in the setting of a large ductal aneurysm.

Cyanotic Heart Disease (Chapters 423, 424, 425)

Unlike the acyanotic forms of congenital heart disease, the majority of patients with cyanotic congenital heart disease will have had at least 1 and often several previous interventions prior to adulthood. The most frequent defects seen in the outpatient adult congenital setting is tetralogy of Fallot, complete transposition of the great arteries (TGA, also known as d-transposition), pulmonary valve stenosis, and various forms of single ventricles. Other defects include total anomalous pulmonary venous return, truncus arteriosus, and double outlet right ventricle.

Tetralogy of Fallot (TOF) (Chapter 424.1)

In the developed world, the unoperated adult patient with tetralogy of Fallot has become a rarity because the majority of patients will have undergone palliation or, more often, repair in childhood. Survival in the unoperated patient to the 7th decade has been described but is rare. In general, only 11% of patients are alive by age 20 yr and only 3% by age 40 yr.

Late survival following repair of TOF is excellent. Repair is typically performed at 3-12 mo of age and consists of patch closure of the VSD and relief of the pulmonary outflow tract obstruction by patch augmentation of the right ventricular outflow tract, pulmonary valve annulus, or both. Survival rates at 32 and 35 yr have been reported to be 86% and 85% respectively, compared to 95% in age- and sex-matched controls. Most patients lived an unrestricted life. Many patients do develop late symptoms that include exertional dyspnea, palpitations, syncope, and sudden cardiac death. Late complications include endocarditis, aortic regurgitation with or without aortic root dilation (typically due to damage of the aortic valve during VSD closure or secondary to an intrinsic aortic root abnormality), LV dysfunction (secondary to inadequate myocardial protection during previous repair or chronic left ventricular volume overload due to long-standing palliative arterial shunts), residual pulmonary obstruction, residual pulmonary valve regurgitation, right ventricular (RV) dysfunction (due to pulmonary regurgitation or pulmonary stenosis), atrial arrhythmias (typically atrial flutter), ventricular arrhythmias, and heart block.

Reintervention is necessary in approximately 10% of patients following reparative surgery at 20-year follow-up. With longer follow-up, the incidence of reintervention continues to increase. The most common indication for reintervention is pulmonary valve replacement for severe pulmonary valve regurgitation.

Transposition of the Great Arteries (TGA) (Chapter 425.1)

The natural history of patients with unrepaired TGA is so poor that very few patients survive past childhood without intervention. The first definitive operations for TGA were described by Dr. Senning in 1959 and Dr. Mustard in 1964 (atrial switch procedures). With these procedures, the systemic and pulmonary venous returns are rerouted in the atrium by constructing baffles. The systemic venous return from the superior and inferior vena cavae is directed through the mitral valve and into the left ventricle (connected to the pulmonary artery). The pulmonary venous return is then directed through the tricuspid valve into the RV (connected to the aorta). These procedures can be performed with low mortality but leave the left ventricle as the pulmonary ventricle and the right ventricle as the systemic ventricle. Long-term follow-up studies after the atrial switch procedure show a small but ongoing attrition rate with numerous other intermediate and long-term complications. Two specific problems after the atrial switch procedure are most concerning. These include the loss of sinus rhythm with the development of atrial arrhythmias, occurring at an incidence of 50% by age 25 yr, and the development of systemic ventricular dysfunction, occurring at an incidence of 50% by age 35 yr. Other long-term complications include endocarditis, baffle leaks, baffle obstruction, tricuspid valve regurgitation, and sinus node dysfunction requiring pacemaker placement.

As result of these long-term complications, the arterial switch operation has become the procedure of choice to treat these patients since 1985. During the arterial switch procedure, the great arteries are transected and re-anastomosed to the correct ventricle (LV to the aorta and the RV to the pulmonary artery) with coronary artery transfer. Operative survival after the arterial switch procedure in the current surgical era is very good, with a surgical mortality rate of 2-5%. Long-term data on survival and complications does not exist but intermediate results are promising. Reported intermediate complications include endocarditis, pulmonary outflow tract obstruction (at the supravalvular level or at the takeoff of the peripheral pulmonary arteries), aortic valve regurgitation, and coronary artery compromise (ranging from minor stenosis to complete occlusion).

Because of the high incidence of observed and potential medical problems, all patients who have had both atrial and arterial repair of transposition of the great arteries should have lifelong follow-up by a cardiologist at a center specializing in adult congenital heart disease.

Pulmonary Valve Stenosis (Chapter 421.1)

Most patients with pulmonary valve stenosis are asymptomatic and present with a cardiac murmur. Survival into adult life and the need for intervention however is directly correlated to the degree of obstruction. Patients with trivial stenosis (defined as a peak gradient <25 mm Hg) followed for 25 yr remain asymptomatic and had no significant progression of obstruction over time. For those patients with moderate pulmonary valve stenosis (defined as a peak gradient of 25-49 mm Hg), there is an approximately 20% chance of requiring intervention by age 25 yr. For those patients with severe stenosis (defined as a peak gradient of >50 mm Hg), the majority ultimately require an intervention, either surgery or balloon valvuloplasty by age 25 yr.

Following surgical valvotomy for isolated pulmonary stenosis, long-term survival is excellent. With longer follow-up the incidence of late complications and the need for reintervention do increase. The most common indication for reintervention is pulmonary valve replacement for severe pulmonary regurgitation. Other long-term complications include recurrent atrial arrhythmias, endocarditis, and residual right ventricular outflow tract obstruction.

Patients with moderate to severe pulmonary stenosis (defined as a peak gradient of >50 mm Hg) should be considered for intervention even in the absence of symptoms. Since 1985, percutaneous balloon valvuloplasty has been the accepted treatment for patients of all ages. Prior to 1985, surgical valvotomy had been the gold standard. Surgical valvotomy is reserved for those patients that are unlikely to have successful results from balloon valvuloplasty, such as those with an extremely dysplastic or calcified valve.

Left-Sided Obstructive Lesions

Coarctation of the Aorta (Chapter 421.6)

The clinical presentation of coarctation of the aorta depends on the severity of obstruction and the associated anomalies. Unrepaired coarctation of the aorta typically presents with symptoms prior to adulthood. These symptoms include headaches related to hypertension, leg fatigue or cramps, exercise intolerance, and systemic hypertension. Those untreated patients surviving to adulthood thus typically have only mild coarctation of the aorta. In the era prior to surgery, without treatment the mean age of death was 32 yr. Causes of death included left ventricular failure, intracranial hemorrhage, endocarditis, aortic rupture/dissection, and premature coronary artery disease.

Following surgical repair, long-term survival is good but is directly correlated with the age at repair, with those repaired after age 14 yr having a lower 20 yr survival than those repaired earlier, 91% compared to 79%. Like almost all forms of repaired congenital heart disease, with longer follow-up the incidence of long-term complications continues to rise. The most common long-term complication is persistent or new systemic hypertension at rest or during exercise. Other long-term complications include aneurysms of the ascending or descending aorta, recoarctation at the site of previous repair, coronary artery disease, aortic stenosis or regurgitation (in setting of bicuspid aortic valve), rupture of an intracranial aneurysm, and endocarditis.

Patients with significant native or residual coarctation of the aorta (symptomatic patients with a peak gradient across the coarctation of >30 mm Hg) should be considered for intervention, either surgery or catheter intervention with balloon angioplasty with or without stent placement. Surgical repair in the adult patient is technically difficult and is associated with high morbidity. Catheter based intervention has become the preferred method in most experienced adult congenital heart disease centers.

Aortic Valve Stenosis (Chapter 421.5)

The natural history of aortic valve stenosis in adults is quite variable but is characterized by progressive stenosis over time. By age 45 yr, approximately 50% of bicuspid aortic valves will have some degree of stenosis.

Most patients with aortic valve stenosis are asymptomatic and are diagnosed after a murmur is detected. The severity of obstruction at the time of diagnosis correlates with the pattern of progression. Symptoms are rare until patients have severe aortic valve stenosis (mean gradient by echocardiography of >50 mm Hg). Symptoms include chest pain, exertional dyspnea, near syncope, and syncope. When any of these symptoms are present, the risk of sudden cardiac death is very high and as result, surgical intervention is mandated.

For patients requiring surgical valvotomy to relieve the stenosis prior to adulthood, the majority of patients do well. However, at 25 yr follow-up, up to 40% of patients will have required a 2nd operation for residual stenosis or regurgitation.

Patients with symptoms and severe aortic valve stenosis should be considered for intervention. Treatment involves manipulating the valve to reduce stenosis. This can be accomplished by transvenous balloon dilation of the valve, open surgical valvotomy, or valve replacement. In absence of significant aortic regurgitation, most centers favor balloon dilation or surgical valvotomy for children and young adults who have pliable valves with fusion of commissures. In older adults, aortic valve replacement is the treatment of choice.

Endocarditis Prophylaxis (Chapter 431)

The American Heart Association found that very few cases of endocarditis are prevented with antibiotic prophylaxis. Only patients with cardiac conditions associated with the highest risk for adverse outcomes should continue follow antibiotic prophylaxis before surgery: patients with previous endocarditis, unrepaired cyanotic congenital heart disease (CHD), including palliative shunts and conduits; completely repaired congenital heart defects with prosthetic material or device, whether placed by surgery or by catheter intervention, during the first 6 months after the procedure; and repaired CHD with residual defects at the site or adjacent to the site of a prosthetic patch or prosthetic device (which inhibit endothelialization). Except for the conditions just listed, antibiotic prophylaxis is no longer recommended for other forms of CHD.

Pregnancy and Congenital Heart Disease

CHD is the most common form of heart disease encountered during pregnancy in developed countries. Heart disease does not preclude a successful pregnancy but increases the risk to both the mother and the baby. During pregnancy there are substantial hemodynamic changes that occur. The hemodynamic changes in pregnancy result in a steady increase in cardiac output during pregnancy until the 32nd week of gestation, at which time, the cardiac output reaches a plateau at 30-50% above the prepregnancy level. At time of delivery, with uterine contractions an additional 300-500 ml of blood enters the circulation. This in conjunction with increased blood pressure and heart rate during labor increases the cardiac output at delivery to 80% the prepregnancy level.

Despite these hemodynamic changes, the outcome of pregnancy is favorable in most women with CHD provided that functional class and systemic ventricular function are good (see Table 428-5). Pulmonary artery hypertension presents a serious risk during pregnancy, particularly when the pulmonary pressure exceeds 70% of systemic pressure, regardless of functional class. Other contraindications to pregnancy include severe obstructive left-sided lesions (coarctation of the aorta, aortic valve stenosis, mitral valve stenosis, hypertrophic cardiomyopathy), Marfan syndrome with coexisting dilated ascending aorta (defined as >4.0 cm), persistent cyanosis, and systemic ventricular dysfunction (ejection fraction of ≤40%). The need for full anticoagulation during pregnancy, although not a contraindication, poses an increased risk to both mother and fetus. The relative risks and benefits of the different anticoagulant approaches need to be discussed fully with the prospective mother.

Pregnancy counseling should begin early in adolescence and should be part of the routine cardiac follow-up visit. During counseling, a discussion about the risk of CHD in the offspring should take place. In the general population, the incidence of CHD is 1%. In the offspring of a mother with CHD, the risk increases to 5-6%. Often the cardiac lesion in the offspring is not the same as that in the mother, except for in the case of a syndrome with autosomal dominant inheritance (Marfan syndrome, hypertrophic cardiomyopathy). Risk stratification should include the specific CHD lesion but also needs to take in account the maternal functional class. While the specific CHD lesion is important, multiple studies have demonstrated that the maternal functional class prior to pregnancy is highly predictive of both maternal and fetal outcomes, with those having the best functional class having the best outcomes.