Cardiac disease in pregnancy and congenital heart disease

Overview
The most common maternal cardiac disease in Western societies is now congenital heart disease. This includes a wide spectrum of abnormalities, which are delineated in this section. This is largely due in part to the fact that children born with congenital heart defects in Western societies are living to the ages at which they can bear children. This section will not detail those patients that have repaired congenital defects, which are highlighted in the Repaired Congenital Heart Disease section.

Classification of disease
Can classify lesions into 3 classes:

I. Volume Overload (L → R shunt)

 * Atrial septal defect, ventricular septal defect, and patent ductus arteriosis well tolerated if pulmonary hypertension not present
 * Peripheral vascular resistance and systemic vascular resistance falls to same degree
 * Degree of shunting does not change


 * Eisenmenger’s Syndrome
 * Maternal and fetal mortality ≥50%
 * Consider termination if detected early
 * Careful medical management
 * -Supplemental O2 during pregnancy
 * -Hospitalization at 20 weeks gestation
 * -Prompt treatment of CHF
 * -Avoid shifts in preload/afterload

II. Pressure Overload

 * Aortic stenosis, mitral stenosis


 * Pulmonic stenosis
 * Degree of obstruction determines outcome
 * Gradient >80 mm Hg mandates correction


 * Coarctation of aorta
 * Accounts for 9% of all congenital disease in adults
 * Class I or II patients usually do well
 * Overall 3.5% mortality in unoperated patients (aortic dissection/rupture, CVA, CHF, endocarditis)
 * HTN needs careful management


 * Hypertrophic cardiomyopathy
 * Early to mid pregnancy, ↑ cardiac output and end-diastolic dimension, ↓ outflow tract obstruction (counteracted by systemic vascular resistance)
 * Avoid Valsalva
 * Encourage left lateral decubitus position


 * Maximum risk period during delivery when blood loss can result in increased gradient + systemic hypotension
 * Keep well hydrated
 * Avoid digoxin, sympathomimetics and excessive diuretics

III. Cyanotic Heart Disease (R → L shunt)

 * Poor prognosticators:
 * Hematocrit > 60%
 * O2 sat<85%
 * Livebirth 12% vs. 92% is sat >90%
 * Systemic right ventricular pressures
 * h/o recurrent syncope


 * Tetralogy of Fallot most common unrepaired defect
 * Drop in systemic vascular resistance leads to increased shunting, deeper cyanosis and rising hematocrit
 * Need to avoid valsava during delivery
 * Maternal mortality more than 4%

Atrial Septal Defects
Pregnancy causes an increase in cardiac output and stroke volume. This can cause an increased left-to-right shunting of blood. Despite the increased workload on heart, females with isolated asymptomatic atrial septal defects tolerate the pregnancy well. Pregnant females with an atrial septal defect may have increased frequencies of some complications for instance arrhythmias, thromboembolism, and bleeding. Despite this, there are no studies suggesting that there are different indications for ASD closure in pregnant females with atrial septal defect when compared to a non-pregnant female with atrial septal defect. The ACC/AHA guidelines, however, do dictate clear deviations in course of treatment in certain special circumstances. According to ACC/AHA guidelines pregnancy could be harmful in females with atrial septal defect and severe pulmonary hypertension (Eisenmenger syndrome)

For further information on ASD, click here

Ventricular Septal Defects
Congential ventricular septal defects VSDs are collectively the most common congenital heart defect. The incidence of VSD in adulthood has decreased over past decades due to successful surgical closure of large defects. Pregnancy in patients with VSD and severe pulmonary arterial hypertension (PAH) (Eisenmenger syndrome) is not recommended owing to excessive maternal and fetal mortality and should be strongly discouraged. See ACC/AHA guidelines for details.

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Patent Ductus Arteriosus
Generally small defects do not cause significant hemodynamic issues during pregnancy. The exception, as in other cases, is with those with pulmonary hypertension. PDAs with a very large shunt may also lead to ventricular failure in the setting of the hemodynamic changes of pregnancy.

For further information on PDA, click here

Aortic Coarctation
Aortic coarctation occurs in approximately 6-10% of all congenital heart disease cases. It often presents in pregnancy due to systemic hypertension. This can lead to small-for-dates babies and fetal loss. Most women have a successful pregnancy with coarctation but may require imaging of the aorta during prenatal care. Treatment options include medical, surgical, and catheter-based therapies.

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Pulmonary Stenosis
Generally congenital pulmonary stenosis is well tolerated if it is mild or repaired by surgery or valvuloplasty. It should be noted that although a woman with severe pulmonic stenosis may be asymptomatic prior to pregnancy, the hemodynamics of pregnancy can lead to right heart failure or atrial arrhythmias. Balloon valvuloplasty is feasible even during pregnancy in the setting of symptoms.

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Congenital Aortic Stenosis
Generally aortic stenosis in women of childbearing age will be secondary to a bicuspid aortic valve. Whether or not pregnancy is contraindicated depends on the severity of aortic stenosis. An echocardiogram should be performed to determine severity; mild aortic stenosis is usually well tolerated in pregnancy, however moderate and severe aortic stenosis may not be well-tolerated. Moderate stenosis may be tolerated in a compliant patient who is monitored closely. In addition, aortic root dilation > 4.5 cm is a contraindication to pregnancy.

Balloon valvuloplasty has been safely performed in a small subset of pregnancy patients with some success, as described by Myerson et al.

For further information on AS, click here

Ebstein Anomaly
Ebstein's anomaly is a congenital heart defect in which the opening of the tricuspid valve is displaced towards the apex of the right ventricle of the heart (congenital apical displacement of the tricuspid valve that typically causes significant tricuspid regurgitation).

The presence of atrial communication and maternal cyanosis greatly increases the risk of pregnancy. In addition, increased right ventricular size, a high degree of tricuspid regurgitation, and atrial arrhythmias all contribute to increased risk during pregnancy. Therefore, safety in pregnancy is quite variable and patients should be followed very closely.

For further information on Ebstein Anomaly, click here