Peripartum/postpartum cardiomyopathy is a dilated cardiomyopathy that may occur in the last trimester of pregnancy through the first several months postpartum.
The estimated incidence in the United States ranges from one in 900 to one in 4000 live births, with an increased incidence among mothers of advanced maternal age and in pregnancies with multiple gestations. A history of pre-eclampsia also appears to confer an increased risk, as do traditional cardiovascular risk factors.
Patients present with a clinical picture consistent with congestive hemodynamics most commonly within a month after delivery:
- exertional dyspnea
- jugular venous distension
- pulmonary rales
- displaced apical impulse
The pathogenesis of post-partum cardiomyopathy is uncertain, with genetic factors, sympathetic tone, hormones, and malnutrition all suggested as contributing factors to its development.
- chest radiograph demonstrates cardiac silhouette enlargement
- appearance is indistinguishable from other forms of dilated cardiomyopathy and the diagnosis is suggested by the patient history
- findings of pulmonary edema are dependent on the amount of systolic dysfunction
Transthoracic echocardiography is often utilized as an initial screening test, which will frequently demonstrate the following:
- left ventricular ejection fraction <45%
- alternatively, a LV fractional shortening <25%
- non-regional (global) pattern of systolic dysfunction
- increased left ventricular volumes
- an elevated end-diastolic internal diameter often used as a surrogate measure (LVIDd >5.3 cm)
- mitral annular dilation may result in functional mitral regurgitation with a central regurgitant jet
- may also involve right ventricular hypokinesis and dilation
- cine SSFP sequences can demonstrate systolic dysfunction, similarly to echocardiography
- delayed enhancement in the left ventricular mid-myocardium has been described in the anterior and anterolateral wall
Treatment and prognosis
The prognosis is better than in other forms of dilated cardiomyopathy, but progressive deterioration of systolic function may occur. A heart transplant may become necessary.
- congenital heart disease
- dilated cardiomyopathy
- the hemodynamic mileiu of pregnancy may result in decompensation of an already dysfunctional left ventricle
- results in elevated end-diastolic pressures and symptomatic heart failure
Gadolinium contrast is contraindicated in pregnant patients and caution should be exercised in considering its use before delivery.
The necessary information for a presumptive diagnosis will often be possible without gadolinium contrast. Contrast may be useful for evaluation of therapeutic response postpartum, however.