Congenital Heart Disease in Pregnancy
Jeannette P. Lin
Key Points
•Congenital heart disease (CHD) is the most common congenital defect, affecting approximately 0.8% of live births
•Over 80% of patients born with congenital heart disease will survive to adulthood
•Aside from bicuspid aortic valves, atrial septal defects (ASDs) are the most common type of congenital heart defect, accounting for 10%–20% of congenital heart defects
•A delivery plan readily accessible to all care providers should be outlined for patients who are at moderate or high risk for maternal cardiac complications
•Patients with Eisenmenger syndrome are at high risk for maternal morbidity and mortality and therefore pregnancy is contraindicated
Introduction
Congenital heart disease (CHD) refers to structural malformations of the heart and/or great vessels that result from abnormal cardiac development in utero or persistence of embryologic structure(s) beyond the first weeks of life (e.g., patent ductus arteriosus). CHD is the most common congenital defect, affecting approximately 0.8% of live births. With improvements in diagnostic tools and advances in surgical and transcatheter techniques, over 80% of patients born with CHD will survive to adulthood. As more women with CHD reach childbearing age, care of these patients requires a multidisciplinary approach with specialists in maternal-fetal medicine, adult CHD, and obstetric anesthesia with expertise in care of this patient population.
When caring for the pregnant patient with CHD, the first step is to identify the patient’s congenital cardiac diagnoses. While some patients have received cardiac care since childhood for their conditions and are well-versed in their diagnoses, others may be unfamiliar with the terminology and unable to name or describe their cardiac condition to their providers. In the latter case, review of imaging and knowledge of CHD may help clarify their diagnoses. While the majority of patients with CHD are diagnosed in childhood, 30% of patients with CHD do not receive their diagnoses of CHD until adulthood. For some, the hemodynamic changes of pregnancy unmask symptoms or murmurs, leading to their congenital cardiac diagnosis.
The second step in caring for the pregnant patient with CHD is to understand their prior congenital cardiac interventions. As Dr. Perloff, one of the founders of the field of adult CHD, eloquently wrote in 1983, nearly all patients with CHD will have either residua or sequelae that warrant lifelong cardiac care [1]. Residua refers to “physiologically unimportant uncorrected defects,” such as bicuspid aortic valve in a patient with coarctation. Sequelae refers to the undesired (but often unavoidable) consequence of a surgical intervention, such as heart block after subaortic stenosis resection. Knowledge of patients’ surgical or procedural history guide surveillance for such residua and sequelae. For example, patients who underwent surgical closure of an atrial septal defect are more likely to have atrial arrhythmias than patients who underwent transcatheter closure of an atrial septal defect due to the presence of atriotomy scars. Finally, providers should seek to understand the patient’s current physiology to guide surveillance and management throughout pregnancy. Although many patients with CHD carry the belief that they were “cured” of their CHD with their childhood surgeries, nearly all patients require lifelong cardiac care [2].
In this chapter, we will review common CHD diagnoses and common residua and sequelae of each defect, and then review the hemodynamic issues often seen in patients with CHD and strategies for management in pregnancy. Table 10.1 outlines a basic checklist for a cardiology or obstetric visit in the pregnant patient with CHD.
Checklist for CHD Visit in Pregnancy | |
Past cardiac history | Congenital cardiac diagnosis Prior surgeries and/or catheter-based interventions Prior arrhythmias and/or electrophysiology study/ablation Implantable cardiac device (pacemaker, implantable cardioverter-defibrillator, loop recorder) and device settings Antiplatelet/anticoagulation, and indication |
Current status | Last cardiology visit Last echocardiogram Last EKG Current NHYA functional class |
Risk assessment | mWHO class ZAHARA CARPREG2 Physiologic stage |
Pregnancy management | Add/hold antiplatelet medications or anticoagulation Echocardiogram frequency BNP frequency EKG frequency CXR frequency Additional testing Additional consultations: Maternal-fetal medicine, adult congenital heart disease specialists |
Fetal surveillance | Risk for anomalies Fetal anatomy, including fetal echo Serial growth Antepartum fetal heart rate testing |
Care of the patient with CHD requires an understanding of the hemodynamic burden of their repaired or unrepaired defect. Hemodynamic burdens can be understood as one or a combination of the following: volume loading, pressure loading, or low cardiac output states (Table 10.2). An overview of common congenital defects and pregnancy management is summarized in Table 10.3.
Hemodynamic Burdens of Congenital Heart Defects | ||||
Hemodynamic Burden | Example(s) | Pregnancy Symptoms | Management Strategies | Comments |
Right heart volume loading | Atrial level shunts | Exertional dyspnea, increased lower extremity edema, atrial arrhythmias | Diuretics | Generally well tolerated in pregnancy but may require diuretic therapy |
Right heart pressure loading | Pulmonary valve/artery stenosis, double chambered right ventricle | Exertional dyspnea, increased lower extremity edema, ventricular arrhythmias | Diuretics, beta-blockers | Consider transcatheter interventions (balloon angioplasty or valvuloplasty) if refractory symptoms |
Left heart volume loading | Mitral or aortic regurgitation | Exertional dyspnea, orthopnea, paroxysmal nocturnal dyspnea, atrial arrhythmias. Ventricular arrhythmias, especially if LV dysfunction | Diuretics, beta-blockers | Generally well tolerated in pregnancy but may require diuretic therapy |
Left heart pressure loading | Coarctation of the aorta, aortic stenosis | Exertional dyspnea, orthopnea, paroxysmal nocturnal dyspnea, atrial arrhythmias. Ventricular arrhythmias, especially if LV dysfunction | Diuretics, beta-blockers | Consider transcatheter interventions (balloon angioplasty or valvuloplasty) if refractory symptoms |
An Overview of Common Congenital Defects and Pregnancy Management | ||||||
Congenital Heart Defect | Hemodynamics | Physical Exam Findings | Findings on Testing | Modified WHO Risk Class | Pregnancy Concerns | Management Recommendation |
Unrepaired atrial level shunts (secundum or primum ASDs, sinus venosus defects, unroofed coronary sinus) | •Left to right interatrial shunt causes volume loading of the right heart •Right ventricular dysfunction (variable) •Mild-moderately elevated pulmonary artery pressures, particularly in older patients | •Split second heart sound •Right ventricular heave •Systolic flow murmur at the left upper sternal border | •EKG: incomplete right bundle branch block •Echo: right atrial and right ventricular dilation •Primum or secundum defects usually well visualized by TTE •Sinus venosus defects and unroofed coronary sinus often require TEE, MRI or CT for diagnosis | II | Paradoxical emboli may cause stroke or myocardial infarction | •Consider aspirin 81 mg daily •Consider anticoagulation with low molecular weight heparin if patient has a cardioembolic event •SBE prophylaxis at time of delivery is reasonable given potential for transient right to left shunting •Bubble/particle filters on IVs |
Unrepaired ventricular septal defect (all types), unrepaired PDA | ||||||
Small VSD or PDA | No significant hemodynamic impact | Small VSD: holosystolic murmur at the left sternal border Small PDA: faint, continuous murmur below the left clavicle | EKG: normal TTE: small VSD or PDA with high-velocity left to right shunt. Normal chamber sizes | II | No significant additional risk | Small VSDs SBE prophylaxis reasonable given small risk of endocarditis |
Medium-sized VSD or PDA | Pressure loading of the right ventricle Mild-moderate pulmonary arterial hypertension Volume loading of the left atrium/left ventricle | Moderate sized VSD: softer holosystolic murmur RV lift if pulmonary hypertension Moderate-sized PDA: continuous murmur below the left clavicle | EKG: may demonstrate RV hypertrophy TTE: •VSD with left to right shunt or PDA with aorta-to-pulmonary artery shunt •Right ventricle hypertrophy and hypertension •Left atrium/ventricle dilation | II-III | Risk for heart failure | •Avoid volume loading •Bubble/particle filters on IVs •SBE prophylaxis reasonable given small risk of endocarditis |
Left ventricular outflow tract obstruction (subvalvar or supravalvar aortic stenosis) | Pressure loading of the left ventricle | •Harsh systolic crescendo murmur at the right upper sternal border •LV impulse may be enlarged if LV hypertrophy is present | EKG: left ventricular hypertrophy TTE: •Left ventricular hypertrophy •Left atrial dilation if longstanding LVH •Subvalvar aortic stenosis (discrete membrane or tunnel-like) with flow acceleration •Supravalvar aortic stenosis typically at the level of the sinotubular junction | II if moderate stenosis III if severe obstruction and patient is symptomatic | If severe: •Risk for heart failure •Right for ventricular or atrial arrhythmias | •Avoid volume loading •SBE prophylaxis reasonable if aortic valve is thickened |
Aortic coarctation | ||||||
Mild native coarctation, or repaired coarctation without significant residual narrowing | No significant hemodynamic impact | •No significant delay between right brachial and femoral pulses •Left upper extremity pulse may be diminished or absent if patient had prior subclavian flap repair | EKG: normal | II | May be prone to hypertension due to aortic stiffness | Avoid checking BP in LUE if prior subclavian flap repair. If unsure whether patient has prior subclavian flap repair, check bilateral upper extremity blood pressures, and follow the higher of the two |
Moderate or severe native or residual coarctation | Left ventricular pressure overload | •Femoral pulse delayed and diminished compared with (right) upper extremity pulse •LV impulse may be enlarged if LV hypertrophy is present | EKG: left ventricular hypertrophy | III (severe asymptomatic) IV (severe symptomatic) | •Hypertension in the upper body, with relative hypotension of the lower body due to gradient across the coarctation •Risk for heart failure | •Monitor upper and lower extremity BPs; placental perfusion will correlate best with LE BPs •Titration of anti-hypertensives as tolerated by mother and fetus •Pain control to avoid fluctuations in blood pressure |
Ebsteins anomaly | •Right heart volume overload if moderate or severe regurgitation •Right ventricular systolic function often abnormal | Widely split-second heart sound, additional heart sounds common If ASD is also present, patient may have cyanosis | EKG: right bundle branch block, PR prolongation are common. Evaluate for preexcitation (Wolff- Parkinson-White syndrome) TTE: right atrial dilation, displaced septal leaflet of the tricuspid valve with elongation of the anterior leaflet, tricuspid regurgitation. Evaluate right ventricular function and assess for secundum ASD | II-III depending on right/left ventricular function, history of arrhythmias, and presence of cyanosis | •Risk for atrial arrhythmias (SVT with or without preexcitation, PACs) •Risk for ventricular arrhythmia, especially if poor ventricular function •Risk for paradoxical embolus if ASD is present | •Monitor for arrhythmias •Avoid volume loading •Bubble/particle filters if ASD is present •SBE prophylaxis if ASD is present |
Pulmonary stenosis, subvalvar pulmonary stenosis, pulmonary artery stenosis | Right heart pressure overload | Systolic crescendo murmur at the left upper sternal border | EKG: right ventricular hypertrophy TTE: stenosis of subvalvar/valvar/supravalvar region(s); right ventricular hypertrophy; right atrial dilation | •I if mild or moderate •II-III if severe | •Risk for atrial or ventricular arrhythmias, particularly with severe stenosis •Risk for right heart failure if RV function is decreased | •Monitor for arrhythmias •Avoid volume loading •SBE prophylaxis |
Tetralogy of Fallot, status post repair | •If chronic severe pulmonary valve regurgitation, right heart volume overload •If pulmonary valve is functional, patient may have relatively normal hemodynamics | •Fixed split-second heart sound •Short diastolic decrescendo murmur if severe PR | EKG: right bundle branch block TTE: repaired VSD Right atrium and right ventricle dilation if chronic severe pulmonary valve regurgitation | II | •Right for atrial or ventricular arrhythmias, particularly if history of prior arrhythmias and/or severe RA/RV dilation •Risk for right heart failure if severe RA/RV dilation or severe RV dysfunction | •Monitor for arrhythmias •Avoid volume loading •SBE prophylaxis |
Double outlet right ventricle, status post Rastelli repair Truncus arteriosus, status post repair | Variable, depending on presence or absence of residual lesions: •RV-PA conduit stenosis or regurgitation •Aortic regurgitation | •Systolic crescendo murmur (flow through RV-PA conduit) •Diastolic decrescendo murmur at the left upper sternal border (RV-PA conduit regurgitation) or right upper sternal border (aortic regurgitation) | EKG: right bundle branch block TTE: repaired VSD; right atrium and right ventricle size, wall thickness and function dependent on status of the RV-PA conduit | II-III, depending on residual lesions | Variable, depending on residual lesions. If significant RV-PA conduit dysfunction, then increased risk of right heart failure | Avoid volume loading if significant RV-PA conduit dysfunction or severe RV dysfunction |
D-Transposition of the great arteries, status post arterial switch | Normal, if no residual lesions Potential late complications include aortic root dilation, aortic regurgitation, and stenosis of the reimplanted coronary arteries | Normal | EKG: normal TTE: abnormal positioning of the aorta and pulmonary artery post-arterial switch. LV function normal in most patients | II if no significant residual lesions | Low risk for complications if no significant residual lesions | Low risk for complications if no significant residual lesions |
D-Transposition of the great arteries, status post atrial switch procedure | •Systemic right ventricle, typically with at least mild systolic dysfunction by adulthood •Tricuspid regurgitation is common, with associated RA/RV volume overload | •Right ventricular lift/heave •Holosystolic murmur (tricuspid regurgitation) | EKG: right ventricular hypertrophy TTE: abnormal position of the aorta (anterior and rightward). Systemic right ventricular systolic function is usually abnormal. Tricuspid regurgitation is common | III if normal or mildly decreased systemic right ventricular function; IV if moderate-severe systemic right ventricular dysfunction | •Risk of heart failure •Risk of ventricular and arrhythmias, especially if prior history of arrhythmias | •Monitor for arrhythmias •Avoid volume loading •SBE prophylaxis |
Congenitally corrected transposition of the great arteries (ccTGA) | •Systemic right ventricle, typically with at least mild systolic dysfunction by adulthood •Tricuspid regurgitation is common, with associated RA/RV volume overload | Right ventricular lift/heave Holosystolic murmur (tricuspid regurgitation) | EKG: right ventricular hypertrophy; q waves in the right precordial leads V1-V2 TTE: leftward systemic right ventricle; Ebsteinoid malformation of the tricuspid valve is associated with ccTGA | •III if normal or mildly decreased systemic right ventricular function •IV if moderate-severe systemic right ventricular dysfunction | •Risk of heart failure •Risk of ventricular and arrhythmias, especially if prior history of arrhythmias | •Monitor for arrhythmias •Avoid volume loading •SBE prophylaxis |
Univentricular hearts, status post Fontan operation | •Systemic venous return flows passively to the pulmonary arteries •Decreased LV preload due to slow transit through the pulmonary arteries •Variable single ventricle function, depending on anatomy | Single S1 and S2 Saturations may be as high as low-mid 90s, or may be lower | EKG: variable depending on underlying anatomy Typically ventricular hypertrophy is seen TTE: variable depending on anatomy. Severe right atrial dilation if patient had an atriopulmonary Fontan | III | •Risk of heart failure •Right of thromboembolic complications •Right of atrial arrhythmias | •Monitor for arrhythmias •Avoid volume loading •SBE prophylaxis •Bubble/particle filters on IVs |