Published: August 2010
Adults with congenital heart disease (CHD) generally fall into two categories: patients who have been recognized, treated, and followed during their pediatric years and subsequently require follow-up during their adult years; and the de novo, previously unrecognized adults who may or may not be symptomatic at the time of diagnosis. Despite the complexity of this patient population and a well-defined need for subspecialty care, the average adult with CHD is followed primarily by a generalist. It is essential, therefore, that all physicians be familiar with the unique clinical presentations of these patients and have a general understanding of their anatomy and its consequences to facilitate the proper timing of referral for percutaneous, electrophysiologic, and surgical interventions.
CHD in the adult is now more prevalent than ever because of the rapid advances in surgical and medical interventions in the pediatric population. As a result, there are now an estimated 750,000 adults with CHD in the United States,1 and this figure excludes patients with bicuspid aortic valves, which are present in up to 2% of the population, and mitral valve prolapse. There are a few generalized syndromes in which a toxic exposure during neonatal development has been linked with the development of CHD. Two classic examples are congenital rubella, in which patent ductus arteriosus has been well described, and women who were administered lithium carbonate during their first trimester of pregnancy, which appears to increase the risk of Ebstein’s anomaly. Most congenital heart disease, however, appears to be caused by genetic abnormalities, a few of which have been well described, but many of which remain to be elucidated. Evidence to support the importance of genetics in CHD includes the much higher risk in the offspring of CHD patients than the 0.8% general population risk; animal models such as transgenic knockout mice that develop cardiac abnormalities; well-described familial kindreds with lesions such as atrial septal defects; and mendelian patterns of inheritance and the common clinical syndromes such as trisomy 21 (Down syndrome), in which atrioventricular canal–type (primum) septal defects are commonly present, and Noonan’s syndrome, in which pulmonic stenosis is often present.2 In general, routine screening of adults for genetic mutations is not currently advocated for most adults with CHD, even for family planning.
The clinical course of CHD in the adult is most dependent on the anatomic lesions present and the timing and manner of repair. These lesions can be divided into three general categories (by decreasing incidence): simple shunt lesions, obstructive lesions, and complex lesions (acyanotic and cyanotic). The most commonly encountered abnormalities in these categories are described next.
Intracardiac shunts are the most common form of congenital heart lesion and are often diagnosed in otherwise healthy adults. They are associated with increased pulmonary blood flow, which can lead to right heart chamber enlargement and arrhythmias, and with pulmonary hypertension. The surgical correction of many of these lesions has been determined to be safe and efficacious. Percutaneous devices have been increasingly used to close these defects to avoid the morbidity and mortality of surgery. There are three common shunt lesions.
The atrial septal defect (ASD) is the most common congenital heart defect encountered in adults, accounting for up to 15% of all adult CHD (Fig. 1). It results from the failure of proper embryologic development of the atrial septum. There are many different types of ASD (Fig. 2), the most common of which is the secundum ASD, in which the defect occurs in the middle of the atrial septum.
The flow of blood across the defect (shunt) is determined by the size of the defect and the compliance of the atria. ASD should be suspected whenever right heart enlargement is present without an alternative explanation. Occasionally, patients present late in life with ASD-related symptoms when the left atrial pressure increases because of a stiff left ventricle and diastolic dysfunction, usually the result of long-standing hypertension or coronary artery disease, resulting in increased shunt.
The larger the left-to-right shunt is in patients with ASD, the greater is the risk for long-term complications, such as atrial fibrillation and pulmonary hypertension. The latter condition affects up to 15% of adults with ASD and, if it remains uncorrected, it can result in Eisenmenger’s syndrome (see later). Another condition associated with ASD is stroke, which presumably results from paradoxical embolization—blood clots forming in the extremities and reaching the cerebral circulation by passing through the ASD.
Other, less-common variations of ASD include the sinus venosus ASD, in which there is abnormal fusion of the vena cava (superior or inferior) to the left atrium. This defect is almost always associated with partial anomalous return of the pulmonary veins (right superior or both right pulmonary veins drain into the right atrium). The primum ASD involves the lower portion of the atrial septum and typically affects the ventricular septum as well (the atrioventricular [AV] canal defect). Both AV valves are structurally abnormal, and the mitral valve is typically cleft. The least common form of ASD involves unroofing of the coronary sinus, which results in shunting into the left atrium. At this time, only the secundum ASD has been successfully occluded through percutaneous means.
Ventricular septal defect (VSD) is the most common congenital heart defect seen in children (Fig. 3). Defects can occur at various locations in the septum but most commonly occur in the membranous (Fig. 4) or muscular portions. Small defects often close spontaneously during childhood. One type of defect, the outflow (or supracristal) VSD, can be spontaneously occluded by one of the aortic leaflets prolapsing into it. This can result in the development of significant aortic insufficiency.
Small VSDs are usually asymptomatic, whereas larger defects are more likely to manifest during childhood with heart failure. VSD is the most common cause of Eisenmenger’s syndrome.
Patent ductus arteriosus (PDA; Fig. 5) is the second most common congenital heart defect seen in adults (approximately 10%-15% of all CHD in adults). PDA is present as an isolated lesion in most adults, unlike in children, in whom it is often seen with more complex heart defects. The ductus connects the descending aorta at the level of the subclavian artery to the proximal left pulmonary artery. As in VSD, patients with a large uncorrected PDA can develop pulmonary hypertension.
Pulmonary stenosis is the most common congenital valve lesion that requires therapy in adults (Fig. 6). Gradients across the pulmonary outflow tract usually occur at the valvular level, but it can also involve the infundibulum (right ventricular outflow tract), peripheral pulmonary arteries, or both. Complications of pulmonary stenosis include right ventricular hypertrophy and eventually failure, as well as arrhythmias.
Coarctation of the aorta (CoA) is a common congenital heart defect (Fig. 7) accounting for approximately 8% of all congenital defects. It probably results from extraneous ductal tissue that contracts following birth. Anatomically, it can occur before, at the level of, or after the ductus arteriosus, although adults with previously undiagnosed CoA almost always have postductal lesions. The most common way it is identified in adults is fortuitous discovery during secondary workup for systemic hypertension. Lower extremity and renal hypoperfusion lead to a hyper-renin state that might not abate, even after coarctation repair. In most patients, there is upper extremity hypertension and the development of collateral vessels around the coarctation to the lower extremity.
Transposition of the great arteries (TGA; Fig. 8) refers to an abnormality in the developmental separation of the great vessels, which results in the aorta emanating from the venous ventricle and the pulmonary artery coming off the systemic ventricle (ventriculoarterial discordance). Two varieties are most commonly seen in adults. The first type is dextrotransposition of the great arteries (d-TGA), with “dextro” initially meant to describe the location of the aorta in respect to the pulmonary artery. In this condition, the right ventricle gives rise to the aorta and the left ventricle gives rise to the pulmonary artery, but both atria are appropriately connected to their respective ventricles (AV concordance). This condition is not compatible with life unless there is a naturally occurring shunt (ASD, VSD, or PDA) or surgically created shunt. Often, these patients have undergone repair during childhood with a Senning or Mustard procedure, in which blood is baffled from the venae cavae to the left atrium and from the pulmonary veins to the right atrium (Fig. 9). The primary long-term concern in these patients is that the right ventricle is ill prepared to serve as the systemic ventricle. It can weaken and fail over time (usually when the patient enters the third or fourth decade), and these patients also develop significant systemic AV regurgitation, with the tricuspid valve in the mitral position.
The other type of TGA is the congenitally (naturally) corrected lesion, levotransposition of the great arteries (l-TGA). In this case, the ventricles are also inverted (both AV and ventriculoarterial discordance are present). This variation (see Fig. 8) results in a circulation in which blood flows from vena cava to right atrium to left ventricle to pulmonary artery to pulmonary veins to left atrium to right ventricle to aorta. Again, the problem remains a right ventricle pumping into the systemic circulation. This condition is also associated with about a one in three lifetime prevalence of complete heart block.
Tetralogy of Fallot (TOF), a conotruncal abnormality, is a constellation of four findings: an aorta that overrides the right ventricular outflow tract; right ventricular outflow obstruction; a large subaortic VSD; and hypertrophy of the right ventricle (Fig. 10). The frequent coexistence of an ASD can make for a pentalogy. Occasionally, patients with unrepaired TOF only present in adulthood because of a remarkable balance between the pulmonic obstruction and the VSD, which limits cyanosis.
Early palliation with a systemic-to-arterial shunt (e.g., Blalock-Taussig), which connects the subclavian and pulmonary arteries (Fig. 11), facilitates growth of the pulmonary arteries and is a precursor to definitive surgical repair in the young child. Definitive repair often involves complete removal of the pulmonic valve (Fig. 12) and therefore results in wide open pulmonic regurgitation. Although the repair is tolerated for several years, the right ventricle eventually succumbs to volume overload and progressively increases in size.
Ebstein’s anomaly (Fig. 13) is the result of inferior displacement of the tricuspid valve into the right ventricle, which results in atrialization of the right ventricle. As a result, the right ventricle is very small and not infrequently hypocontractile. The posterior and septal leaflets of the tricuspid valve are often small and inadequate, and the anterior leaflet is very large and redundant, resembling a sail. About 25% of Ebstein’s anomaly patients have accessory pathways for AV conduction (Wolff-Parkinson-White syndrome), which often are multiple. About 50% of patients also have an ASD or a patent foramen ovale (PFO), and right-to-left shunting through these defects results in cyanosis.
Eisenmenger’s syndrome (Fig. 14) is a condition in which an intracardiac shunt results in such severe pulmonary hypertension that right-sided pressures eventually exceed systemic pressures and reversal of the intracardiac shunt (becoming right to left) occurs.3 Oxygen saturation does not improve in patients with this complication when oxygen is administered to them (the telltale sign of a right-to-left shunt). Multiple complications eventually ensue and, until recently, this condition was considered irreversible.
Although patients with Eisenmenger’s syndrome have much better long-term survival than comparable patients with idiopathic (primary) pulmonary hypertension, rapid deterioration can be seen during atrial or ventricular arrhythmias or with complications such as pulmonary embolism or infection, or generally with any condition that results in even transient hypotension. Patients with Eisenmenger’s syndrome also are at increased risk of developing hemoptysis, which in some cases can be life threatening.
There are also a number of complications that result from long-standing hypoxia, including significant erythrocytosis, elevated red blood cell count. Symptoms of hyperviscosity—changes in mental status, fatigue, and headache—are rare, and phlebotomy should only be performed to relieve these symptoms. Patients with Eisenmenger’s syndrome often develop proteinuria and a decreased glomerular filtration rate (GFR). Because of the low GFR and the high turnover of red blood cells, uric acid levels are often elevated and can result in acute renal failure, particularly after administration of contrast dye if the patient is not adequately hydrated.
The manifestation of CHD varies significantly, according to the type of anatomic defect present. Certain signs and symptoms should prompt an extensive evaluation of adults with CHD, particularly syncope and progression in exertional dyspnea. Simple shunt lesions such as secundum atrial septal defects are often overlooked because the symptoms associated with them, fatigue and breathlessness, can be subtle and nonspecific. Physical examination findings, including a fixed, split, second heart sound (because of loss of differential effects on right- and left-sided filling pressures from a drop in intrathoracic pressure, which normally occur during inspiration) and a pulmonic outflow murmur (the result of increased pulmonary blood volume from shunting) are also commonly missed.
A small VSD produces a loud systolic murmur and often a palpable thrill at the left sternal border, but patients are generally asymptomatic. Larger defects have softer murmurs, but these are more likely to manifest during childhood with signs and symptoms of congestive heart failure. Patients with PDA have a continuous murmur (systole and diastole) that is often described as a “machinery murmur.” This is heard best under the left clavicle and is accompanied by a widened pulse pressure.
Patients with stenotic lesions often remain asymptomatic until significant levels of narrowing develop. In the case of right-sided lesions, fatigue and lower extremity edema develop, whereas in left-sided lesions, shortness of breath predominates, secondary to pulmonary edema. With coarctation of the aorta, patients occasionally complain of leg fatigue during exercise, indicating inadequate lower extremity perfusion caused by the severity of the stenosis and inadequacy of collateral vessels. These patients may also have evidence of a murmur that continues into diastole, as well as a significant brachial-femoral pulse delay.
Patients with l-TGA or surgically repaired d-TGA are typically asymptomatic for many years, until their systemic ventricle begins to fail. Early on, the physical examination can be unremarkable, other than mild systemic AV valve regurgitation (provided no other anatomic defects are present). Once failure ensues, the signs and symptoms are not unlike those of the typical heart failure patient. The acute onset of dizziness or fatigue should prompt a thorough workup to exclude the presence of symptomatic heart block.
In patients with TOF and prior surgical repair, significant pulmonic insufficiency may be present. Because this is low-pressure regurgitation, however, it may be barely audible on examination. In Ebstein’s anomaly, on the other hand, the physical examination is usually less subtle. The large anterior leaflet of the tricuspid valve often makes a loud snapping noise described as a “sail sound,” which occurs during closure of the valve. It is typically followed by a tricuspid regurgitation murmur, if present. In patients with an accompanying ASD, a fixed, split, second heart sound and pulmonic outflow murmur may also be present. As a result of this interatrial flow communication, right-to-left shunting can occur during physical exertion and lead to cyanosis and reduced exercise tolerance.
The physical examination of a patient with Eisenmenger’s syndrome is notable for cyanosis, which typically worsens during exercise, and clubbing. If differential clubbing is present, usually clubbing of the feet and left arm and not the right arm, depending on the location of the PDA, the clinical diagnosis is Eisenmenger’s physiology in the context of PDA. Because pulmonary and systemic pressures differ only slightly, a murmur across the shunt lesion is generally not heard in Eisenmenger’s syndrome patients.
An organized approach is especially important in the workup of patients with CHD, and the critical first step is obtaining a complete history. Reviewing the pediatric records, if available, is essential to understand the complexities of the cardiac and vascular anatomy and to define the outcomes of previous diagnostic studies and surgeries. Surgical procedures have changed considerably over the last several decades, and anatomic presumptions based on current practice might not apply.
Early steps in assessing the adult patient with CHD include reviewing the electrocardiogram (ECG) and the chest radiograph. The ECG, by showing tall R waves in the anterior precordial leads with ST-T changes in the opposition direction to the QRS complex, can raise awareness that right ventricular pressure overload is present; this suggests the presence of pulmonary hypertension or obstruction to right ventricular outflow. ECG might also detect the presence of high-grade heart block, as in the case of corrected transposition; this has an incidence of 1% to 2% per year. In TOF patients who have not yet undergone reoperation for pulmonic insufficiency, a measure of QRS width of more than 180 msec appears to predict a higher risk of sudden death.4 In the case of atrial septal defect, the ECG can be useful to differentiate between different types (Table 1). The secundum defect often has an incomplete right bundle branch block (RBBB) pattern and a rightward axis, whereas the primum defect has a complete RBBB, a leftward axis, and, occasionally, a first-degree AV block. The ECG of Ebstein’s patients shows very tall (Himalayan) P waves, which are a characteristic finding.
|Feature||Secundum ASD||Primum ASD||Sinus Venosus ASD|
|Anatomic feature||Partial anomalous pulmonary venous return (only ~10%)||Mitral valve involvement; ±VSD||Partial anomalous pulmonary venous return|
|Physical examination findings||Fixed split S2; pulmonic outflow murmur||Same as secundum ASD; murmurs of MR ± VSD||Same as secundum ASD|
|Electrocardiographic findings||RSR' pattern; incomplete RBBB; ±right axis||RBBB; left axis; ± 1-degree AV block||Same as secundum ASD; ± leftward-shifted P wave axis (inverted P in lead III)|
ASD, atrial septal defect; AV, atrioventricular; MR, mitral regurgitation; RBBB, right bundle branch block; VSD, ventricular septal defect.
The chest radiograph can detect generalized problems, such as increased lung vascularity caused by a shunt lesion (Fig. 15) or the presence of pulmonary vascular congestion in patients with elevated left heart filling pressures. It can also detect specific problems, such as rib notching produced by collateral vessels resulting from an aortic coarctation (Fig. 16).
Echocardiography is widely available and useful in the workup of adults with CHD. Limitations of echocardiography include difficult windows caused by excessive scar tissue from previous surgeries, concomitant lung disease, and obesity. Certain lesions, such as sinus venosus ASD, which are not seen on transthoracic imaging, require transesophageal echocardiography or advanced radiographic imaging to confirm the diagnosis.
The use of computed tomography (CT) or magnetic resonance imaging (MRI) can add substantially to the anatomic description of CHD, especially in patients with unclear great vessel (Fig. 17), pulmonary vascular, or coronary anatomy (Fig. 18). The use of MRI has expanded, with more widely available scanners and simplified scanning protocols. It is important to remember, however, that CT scanning is complicated by the need for intravenous contrast, and MRI is generally not compatible with current implantable cardiac pacemakers and defibrillators.
Diagnostic cardiac catheterization, although generally performed later in the diagnostic workup of CHD patients than in the past, remains the gold standard for pressure measurement, cardiac output calculation, and vascular resistance determination. The relative sizes of shunt lesions can be assessed using oximetry, and the hemodynamic consequences of additional blood flow can be assessed. Most importantly, cardiac catheterization affords the opportunity to intervene and palliate or repair anatomic defects or to clarify the suitability of further surgical intervention.5
Anatomic shunting can be quantified in the catheterization laboratory by examining the blood oxygen saturations in the respective chambers. The mixed venous (MV) saturation is the saturation of blood returning to the right atrium (RA), with contributions from the inferior vena cava (IVC), superior vena cava (SVC), and coronary sinus (CS). IVC saturation is normally higher than the SVC because of high renal blood flow and less oxygen extraction by the kidneys. The CS saturation is very low, but its volume of contribution is negligible and usually ignored. To normalize the MV saturation, three times the SVC saturation is added to the IVC saturation and the sum divided by 4.
Because so much mixing of blood with differing saturations occurs in the RA, an 11% increase in oxygen step-up (saturation increase from a chamber to its successive chamber) is required to diagnose a shunt lesion between the SVC and the RA. A 7% increase is necessary to detect a shunt between the RA and right ventricle (RV) and a 5% increase is necessary to detect a shunt between the RV and pulmonary artery (PA). A quick and simple measure of the overall size of a left-to-right shunt ratio can be obtained by using the following formula:
The PV saturation can be assumed to be 95% if it is not measured directly.
In general, a significant shunt is present when the shunt ratio is 1.5 : 1. This simplified definition may not apply to older adults, however. As pulmonary hypertension develops and RV compliance falls, a left-to-right shunt that was 3 : 1 for 30 years may become lower than 1.5 : 1 because of the gradual reversing of the shunt. In fact, the left-to-right shunt may totally reverse at some point and result in arterial desaturation (Eisenmenger’s syndrome). The significance of a shunt in the adult, therefore, must be examined in the context of other hemodynamic parameters, chamber sizes, and history of the defect over time.
Pulmonary hypertension is a common complication of certain congenital heart diseases and can be secondary to pulmonary venous hypertension from elevated left-sided filling pressures, or it can be the result of systemic-to-pulmonary artery shunting. To help differentiate the cause of pulmonary hypertension, the pulmonary vascular resistance (PVR) can be determined at catheterization:
A high resistance (>7 Wood units or a ratio of the pulmonary-to-systemic vascular resistance >0.5 : 1) has been associated with considerably higher perioperative mortality.6 In addition, assessment of pulmonary vascular reactivity with endothelium-dependent vasodilators, such as inhaled nitric oxide or intravenous adenosine, may provide additional prognostic information in these patients by confirming whether the observed pulmonary hypertension has a vasoconstrictor component.7
Adults with CHD are a unique patient population, particularly those whose CHD has been diagnosed and treated early in life. They are typically accompanied by their parents to office visits, particularly if they have other physical and mental impediments. In some cases, their knowledge and insight into their disorders may be limited and they may depend on their parents to recall their prior history. In other cases, the patient may have an encyclopedic background about the disorder and may know more about state-of-the-art management than the physician. It is always best to obtain as many prior medical records as possible to ensure a clear understanding of the condition and how it has been previously treated.
It is important to recognize that although these patients have been followed by cardiologists, many of them have not been previously instructed about risk factors for atherosclerotic disease. Metabolic syndrome—the constellation of insulin resistance, hypertension, abdominal obesity, and lipid abnormalities—appears at least as prevalent as in the general population; recent studies have shown that many of these patients are in a state of physical conditioning that is on par with that of the heart failure population.8 In many cases, patients have been instructed to avoid certain activities or have avoided activity because of a fear of possible medical consequences. Generally, exercise should be encouraged and cardiac rehabilitation should be strongly considered.
Patients with metabolic syndrome should be instructed in more heart-healthy diets and encouraged to engage in physical activity. Patients with heart failure should also receive instruction about low-salt diets and how to detect subtle evidence of clinical decompensation before it occurs.
Unlike other areas in cardiovascular medicine, medical therapy in adults with CHD is based on limited clinical data. In general, recommendations are difficult to make and formalized guidelines are not yet available for most of the problems encountered in cyanotic heart disease and for 6 months following most surgical and percutanbous cardiac procedures.
The adult with CHD and atrial fibrillation should be managed aggressively, because this rhythm can be poorly tolerated. Anticoagulation should be considered in almost all these patients, unless contraindications exist. Certain rhythms, such as atrial flutter, are usually related to scar tissue from previous surgery, and ablation therapy may be curative.9
In transposition patients with heart failure and a failing systemic right ventricle, the general approach has been to use commonly accepted heart failure medications: angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers, beta blockers and spironolactone for possible mortality and heart remodeling benefits, and digoxin and diuretics for symptoms. One must be particularly careful with beta blockers, however, given the risk of precipitating heart block. Whether patients with systemic morphologic right ventricles without heart failure or patients with single ventricles benefit from agents such as ACE inhibitors to prevent heart failure is currently unknown.
For most other conditions, surgical or percutaneous therapy remains the mainstay of management; the details used in selecting therapy follows. Indications to repair an ASD have historically included evidence of right heart volume overload (resulting from the ASD) or the presence of a hemodynamically significant defect (classically a of 1.5 : 1). Examples of devices designed to percutaneously close atrial septal defects are illustrated in Figure 19. The timing of closure of an ASD appears important, because repair after the age of 40 years is associated with an increased incidence of arrhythmias (e.g., atrial fibrillation) compared with repair before age 40.10 Epidemiologic evidence also suggests that long-term survival is worse if ASD is left unrepaired.
Most VSDs encountered in the adult population are small and require little more than observation. However, some experts believe that any PDA should be occluded to prevent endarteritis and to remove any excess flow from the pulmonary circuit, which could result in volume overload over time. PDAs can be ligated surgically or closed percutaneously, using device closure or coils, depending on size.
Careful tracking of the gradient in patients with pulmonic stenosis is critical for decision making. Generally, an intervention is believed to be warranted when the transvalvular gradient exceeds 50 mm Hg (moderate or greater PS), although patients with lesser gradients may benefit if it can be clearly shown that exertional symptoms, typically dyspnea, accompany elevated gradients during provocation. Percutaneous balloon valvuloplasty has proved to be safe and effective in the adult and is the therapy of choice for patients with significant stenosis.
Surgery has previously been the mainstay in the approach to a native CoA, with available options including resection and end-to-end anastomosis, prosthetic patch aortoplasty, interposition (tube bypass) grafting, and subclavian to distal aorta bypass (Fig. 20). Angioplasty and stenting is now considered the procedure of choice in patients with recoarctation following surgery and is experiencing an expanding role in primary treatment.
Surgical repair for systemic AV valve regurgitation in transposition of the great vessels is generally ineffective, and cardiac transplantation is often considered if symptoms of heart failure are severe and refractory. In select medical centers, some success has been achieved in younger patients by using a staged procedure, in which the pulmonic outflow tract is first banded to train the morphologic left ventricle to withstand systemic pressures again. The second step involves removing these bands and performing an arterial switch, with or without takedown of the atrial baffle or the creation of such a baffle.
Surgical repair of pulmonic insufficiency in repaired TOF involves implanting a pulmonic valve bioprosthesis or homograft. This is indicated if progressive decline in exercise tolerance, decrement in right ventricular function, or severe widening of the QRS complex on the ECG can be demonstrated.
Surgery in Ebstein’s anomaly involves complex repair of the tricuspid valve in addition to closure of the atrial communication. It should be limited to centers with extensive experience in this area. Indications for surgery include significant cyanosis, severe tricuspid regurgitation and right heart enlargement (often defined as a cardiothoracic ratio >60%), or the development of symptomatic right heart failure.
Pregnancy in women with congenital heart disease has important considerations. In most cases, cardiologists with experience in managing congenital disease and specialists in high-risk obstetrics should be consulted early in the process. Usually, it is best for the patient to meet with these physicians before family planning, particularly in cases with a high risk of fetal recurrence. Any medications the prospective mother is taking need to be carefully reviewed to avoid possible teratogenicity. The two groups of women with CHD at highest risk of maternal mortality are those with severe pulmonary hypertension and those with Eisenmenger’s syndrome. These patients should be counseled not to become pregnant and, if they do, may need to consider early termination.
Patients with most other lesions can be safely guided through pregnancy, although rates of fetal loss can be significantly higher. Simple shunt lesions are generally well tolerated, but filters should be placed on all IV lines at the time of delivery. Administration of antibiotics at the time of delivery also may be beneficial. Vaginal delivery is generally favored in most women with CHD. However, certain populations, such as those with high-grade obstructive lesions, may benefit from elective cesarean section to avoid prolonged Valsalva maneuvers during labor, which could lead to rapid hemodynamic deterioration.