In a 21‑year‑old woman, 6 weeks postpartum, presenting with acute shortness of breath, diaphoresis, tachycardia, and a productive cough, with a normal lung examination, tachycardia on electrocardiogram, and hemoglobin of 10 g/dL, what is the most likely cause of her symptoms?

Peripartum Cardiomyopathy

In this 21-year-old woman presenting 6 weeks postpartum with acute dyspnea, diaphoresis, tachycardia, and clear lung fields, peripartum cardiomyopathy is the most likely diagnosis. 1

Clinical Reasoning

Why Peripartum Cardiomyopathy is Most Likely

• Peripartum cardiomyopathy (PPCM) typically presents between the last month of pregnancy and 5 months postpartum, with peak incidence in the first postpartum month 1
• The classic presentation includes dyspnea, tachycardia, and diaphoresis—exactly matching this patient's symptoms 1
• Clear lung fields on examination do NOT exclude PPCM; early cardiac dysfunction can present before overt pulmonary edema develops 1, 2
• The postpartum period represents the highest risk time for cardiovascular decompensation due to auto-transfusion from uterine contraction and mobilization of extravascular fluid 1, 2

Why Other Diagnoses are Less Likely

Anemia (Hemoglobin 10.1 g/dL):

• While anemia can cause dyspnea and tachycardia, a hemoglobin of 10.1 g/dL is mild and would not typically cause acute, severe symptoms in an otherwise healthy young woman 3, 4
• Anemia-related dyspnea is typically exertional and gradual in onset, not acute over 24 hours 5, 6
• The productive cough and diaphoresis are not explained by anemia alone 6

Pulmonary Embolism:

• While PE is a critical consideration in the postpartum period (incidence 0.1-0.67 per 1000 pregnancies with highest risk immediately postpartum), the clear lung examination makes this less likely 1, 7
• PE typically presents with pleuritic chest pain, hemoptysis, or signs of right heart strain—not mentioned in this case 1, 7
• However, PE must still be ruled out with D-dimer and imaging if clinical suspicion remains, as 90% of PE patients have dyspnea and tachypnea 1, 7

Aortic Dissection:

• Aortic dissection would typically present with severe, tearing chest or back pain—not described here 1
• This is more common in patients with Marfan syndrome or other connective tissue disorders 1

Diagnostic Approach

Immediate Evaluation Required

• Urgent echocardiography is mandatory to assess left ventricular ejection fraction (LVEF), with PPCM defined as LVEF <45% in the absence of other causes 1, 2
• ECG findings may show sinus tachycardia, non-specific ST changes, or T-wave abnormalities—all normal pregnancy findings that don't exclude cardiac pathology 1
• B-type natriuretic peptide (BNP) should be measured; it is NOT elevated in normal pregnancy and elevation suggests cardiac dysfunction 1
• Troponin may be elevated in PPCM even without coronary artery disease 1

Critical Pitfall to Avoid

• Do NOT attribute dyspnea and tachycardia to "normal postpartum changes" or mild anemia without cardiac evaluation 1
• Cardiovascular disease is the leading cause of maternal mortality in developed countries, and delayed diagnosis of PPCM significantly worsens outcomes 1
• The productive cough may represent early pulmonary congestion from left ventricular dysfunction, even before frank pulmonary edema appears on examination or chest X-ray 2

Immediate Management Considerations

If PPCM is Confirmed

• Admit to ICU for continuous hemodynamic monitoring for at least 24 hours 2
• Initiate standard heart failure therapy including diuretics (furosemide 20-40 mg IV), vasodilators if BP permits, and beta-blockers after acute stabilization 2
• Consider bromocriptine 2.5 mg twice daily to stop lactation and potentially enhance cardiac recovery, but MUST be accompanied by prophylactic anticoagulation due to thrombotic risk 2
• Administer thromboprophylaxis with low-molecular-weight heparin once hemodynamically stable, as postpartum women with cardiac dysfunction have significantly elevated thromboembolic risk 2

Critical Medication Contraindications

• NEVER administer methylergonovine (ergometrine) for any postpartum bleeding in this patient—it causes significant vasoconstriction and can precipitate acute cardiac decompensation 2, 8
• If postpartum hemorrhage occurs, use oxytocin as the first-line uterotonic and tranexamic acid if needed 9, 8

Role of Anemia

• The mild anemia (Hb 10.1 g/dL) may be contributing to increased cardiac workload through compensatory tachycardia and increased stroke volume, but is not the primary cause of her acute presentation 3, 5
• If PPCM is confirmed, correcting the anemia may reduce cardiac stress and improve symptoms, but cardiac-directed therapy is the priority 3