Figure 3: ECG of case 3 showing S1Q3T3 (right heart strain) pattern
Discussion:
Peripartum cardiomyopathy is a rare disease, often dilated cardiomyopathy of late pregnancy or early postpartum period without another known cause of heart failure.5–7 PPCM has been defined as a heart failure that occurs in the last month of pregnancy or up to five months postpartum with left ventricular systolic dysfunction (left ventricular ejection fraction (LVEF) <45% or fractional shortening <30%, or both).1
Peripartum cardiomyopathy has been described in less than 0.1 percent of pregnancies with variable outcomes i.e. complete recovery or progression to severe cardiac failure and even sudden cardiac death.8
The etiology of PPCM is unclear, however, several risk factors have been identified so far. Among them, genetic predisposition, viral myocarditis, stress-activated cytokines, abnormal immune response to pregnancy, maladaptive response to hemodynamic stresses of pregnancy, excessive prolactin excretion, and prolonged tocolysis have been suggested as possible factors.7,8 Although exact etiology could not be identified in our cases, the condition in case two might have been precipitated by pyelonephritis.
Since most of the clinical presentations are similar to symptoms of advanced pregnancy, diagnosis can be missed. Majority of patients present with typical features of heart failure such as dyspnea, orthopnea, cough and chest pain, hemoptysis, and paroxysmal nocturnal dyspnea.5,9 Likewise, all of our three cases developed dyspnea, orthopnea, and dry cough during the first week of puerperium.
Physical examination usually reveals tachycardia, tachypnea, raised jugular venous pressure, displaced apical impulse, right ventricular heave, S3, and S4 gallop, murmurs of mitral and tricuspid regurgitation, rales, hepatomegaly and edema.8,9 This was consistent with our cases who also had bilateral lower limb edema and bilateral basal lung crepitation.
PPCM can be investigated through several diagnostic modalities that include electrocardiography, chest radiography, echocardiography, and lab investigations such as BNP. ECG shows sinus rhythm, often with non-specific ST-segment or T-wave abnormalities. Chest radiography most often reveals indications of heart failure such as cardiomegaly, pulmonary congestion, and pleural effusions.8 This finding was in keeping up with our cases as the Chest radiograph of cases two and three showed pulmonary edema, and that of case one showed pleural effusion. Patients with acute PPCM usually have elevated plasma concentrations of natriuretic peptides.10 The diagnosis is confirmed by the echocardiographic findings of left ventricular systolic dysfunction.1
The differential diagnosis includes other causes of heart failure such as familial dilated cardiomyopathy, previous myocarditis, drug or toxin-induced cardiomyopathy, adult congenital heart disease, valvular disease, and pulmonary arterial hypertension among others.6,7
Acutely presented PPCM is similarly managed as acute heart failure of other etiologies.10 Women in the peripartum period should be managed by a multidisciplinary approach including cardiologists, intensivists, obstetricians, neonatologists, anesthesiologists, and cardiac surgeons.7,10. Fluid and salt restriction is the mainstay of volume management, and loop diuretics may be added for symptomatic pulmonary or peripheral edema, taking care to avoid over-diuresis during pregnancy to prevent placental hypoperfusion.8 Beta-blockers, hydralazine, and nitrates are also indicated for patients with PPCM. However, angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), angiotensin receptor-neprilysin inhibitors (ARNI), ivabradine and mineralocorticoid receptor antagonists (MRAs) are contraindicated because of the possibility of teratogenicity.7
Important complications include severe heart failure, cardiogenic shock, arrhythmias, thromboembolic events, and death.9Moreover, there is an increased risk of PPCM in subsequent pregnancies with increased morbidity and mortality, particularly in women with persistent left ventricular systolic dysfunction after the first pregnancy.11 In our experience, case three developed acute kidney injury during the disease.
Recovery typically occurs between 3 and 6 months postpartum, but there may be a delayed recovery as late as 48 months postpartum due to several factors such as delayed diagnosis, higher NYHA functional class, black ethnicity, LV thrombus, multiparity, and coexisting medical illnesses.5
To conclude PPCM despite being rare should be considered in women presenting with features of left ventricular failure in the later months of pregnancy or within five months of delivery. Acutely presenting PPCM that is managed as acute heart failure of other etiologies, can have devastating consequences if not diagnosed and treated early.