Correct Answer: D. Left ventricular diastolic dysfunction
Peripartum cardiomyopathy (PPCM) is a form of dilated cardiomyopathy characterized by systolic dysfunction, not diastolic dysfunction. The hallmark pathophysiology involves impaired contractility of the left ventricle with reduced ejection fraction (typically <45%), leading to systolic heart failure. The left ventricle becomes dilated and hypokinetic, with severely reduced systolic function. Diastolic dysfunction (impaired relaxation or filling) may occur secondarily as a consequence of the dilated, stiffened ventricle, but it is NOT the primary or defining feature of PPCM. The diagnostic criteria emphasize systolic dysfunction: development of heart failure in the peripartum period (5 months before to 5 months after delivery) with reduced ejection fraction and absence of other identifiable causes. Indian guidelines and standard cardiology texts (Harrison, Robbins) define PPCM by systolic impairment, not primary diastolic dysfunction. Therefore, "left ventricular diastolic dysfunction" as a defining characteristic is incorrect—it is systolic dysfunction that defines this condition.
Why the other options are wrong
A. Absence of identifiable cause — This is a core diagnostic criterion of PPCM. By definition, PPCM is a diagnosis of exclusion—heart failure developing in the peripartum period without identifiable cause such as coronary artery disease, myocarditis, or pre-existing cardiomyopathy. The absence of an obvious etiology is what makes it 'peripartum' cardiomyopathy rather than secondary heart failure. This statement is TRUE. B. Dilated left ventricle — Dilation of the left ventricle is a hallmark finding in PPCM. The condition is classified as a dilated cardiomyopathy, characterized by ventricular enlargement and systolic dysfunction. Echocardiography typically shows increased left ventricular end-diastolic dimension and reduced ejection fraction. This structural finding is TRUE and essential to the diagnosis. C. Development of cardiac failure within 5 months of delivery — The temporal relationship to delivery is a defining diagnostic criterion of PPCM. Heart failure must develop between 5 months antepartum and 5 months postpartum for the diagnosis to be made. This narrow peripartum window distinguishes PPCM from other causes of dilated cardiomyopathy. This statement is TRUE and is part of the standard diagnostic criteria used in Indian and international practice.
High-Yield Facts
- PPCM is defined by systolic dysfunction (reduced ejection fraction, typically <45%), not diastolic dysfunction—this is the key discriminator in 'except' questions.
- Diagnostic window: 5 months before to 5 months after delivery—heart failure must develop within this peripartum period to qualify as PPCM.
- Dilated left ventricle with reduced ejection fraction is the characteristic echocardiographic finding; the ventricle is enlarged and hypokinetic.
- Diagnosis of exclusion—PPCM requires absence of identifiable cause (no CAD, myocarditis, valvular disease, or pre-existing cardiomyopathy).
- Indian risk factors: multiparity, maternal age >30 years, preeclampsia, gestational hypertension, and malnutrition increase PPCM risk in Indian populations.
Mnemonics
PPCM = Peripartum + Systolic (not Diastolic) Remember: PPCM = Systolic dysfunction (dilated, weak ventricle). Diastolic dysfunction (stiff ventricle, impaired filling) is NOT the defining feature. The 'S' in systolic is your clue—systolic = squeeze, and PPCM is about loss of squeeze. 5-5-5 Rule for PPCM Diagnosis 5 months before delivery to 5 months after delivery = diagnostic window. 5 months is the cutoff for peripartum classification. Use this to exclude cases outside this window.
NBE Trap
NBE pairs PPCM with "diastolic dysfunction" to trap students who confuse systolic and diastolic heart failure or who conflate PPCM with restrictive cardiomyopathy (which IS characterized by diastolic dysfunction). The question tests whether students know that PPCM is fundamentally a systolic disease.
Clinical Pearl
In Indian obstetric practice, PPCM is increasingly recognized in multiparous women with preeclampsia or gestational hypertension. The key bedside clue is a young woman presenting with acute dyspnea and orthopnea in the third trimester or early postpartum period, with an echocardiogram showing a dilated, poorly contracting left ventricle (low ejection fraction)—this is systolic failure, not diastolic stiffness.
_Reference: Harrison Ch. 281 (Cardiomyopathies); Robbins Ch. 12 (Heart); DC Dutta Obstetrics (Cardiac Complications in Pregnancy)_