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.