In a pregnant woman presenting with substernal chest pain, fever of 102.4 °F, shortness of breath, mild bilateral pleural effusions on chest X‑ray, Q waves in the inferior leads, T‑wave inversions in leads II, III, aVF, and V1, normal troponin levels, negative influenza test, and normal white blood cell count, what is the most likely assessment?

Assessment: Acute Pericarditis with Possible Myopericarditis

The most likely diagnosis in this pregnant patient is acute pericarditis, potentially with myopericardial involvement, though pulmonary embolism must be urgently excluded given the high maternal mortality risk.

Primary Diagnostic Considerations

Acute Pericarditis (Most Likely)

The clinical presentation strongly suggests pericarditis based on:

• Substernal chest pain (classic pericardial pain pattern)
• Fever (102.4°F) indicating inflammatory process
• Bilateral pleural effusions (pericardial inflammation commonly extends to pleura)
• ECG changes: Q waves in inferior leads with T-wave inversions in II, III, aVF, and V1 suggest pericardial inflammation rather than true myocardial infarction
• Normal troponin (<6) argues against significant myocardial injury, though pericarditis can occur with normal troponin 1
• Normal WBC does not exclude viral or idiopathic pericarditis

The ECG pattern with Q waves and T-wave inversions can occur in pericarditis due to epicardial inflammation and should not be immediately interpreted as myocardial infarction, especially with normal troponin.

Critical Differential: Pulmonary Embolism (Must Exclude)

PE is a leading cause of maternal mortality and must be ruled out urgently 2. The presentation overlaps significantly:

• Chest pain, dyspnea, and pleural effusions occur in PE
• ECG changes including inferior lead abnormalities can mimic PE 3
• Pregnancy is a hypercoagulable state with increased PE risk
• Normal troponin does not exclude PE (troponin may be normal or mildly elevated in PE)

Diagnostic Algorithm

Immediate steps:

1. Perform bilateral lower extremity compression ultrasound (CUS) if any leg symptoms present 4, 2

   • If positive: treat for PE immediately
   • If negative: proceed to pulmonary vascular imaging

2. Since chest X-ray is already abnormal (bilateral effusions), proceed directly to CTPA rather than V/Q scan 4, 2

   • The 2019 ESC and 2011 ATS guidelines recommend CTPA when chest X-ray is abnormal 4, 2
   • Use low-radiation dose protocol for pregnancy

3. Echocardiography is essential to:

   • Assess pericardial effusion size and hemodynamic significance
   • Evaluate for cardiac tamponade (critical in pregnancy) 5, 6
   • Assess ventricular function
   • Look for right ventricular strain (suggests PE)

4. Additional workup for pericarditis etiology:

   • Viral serologies (though flu is negative, consider other viruses)
   • Autoimmune markers (ANA, anti-dsDNA, complement levels) - lupus pericarditis is well-documented in pregnancy and can be life-threatening 5, 7
   • Consider pericardiocentesis if large effusion or tamponade physiology

Critical Clinical Pitfalls

Do not assume normal troponin excludes cardiac pathology. Pericarditis, especially isolated pericarditis, frequently presents with normal troponin 1. The absence of troponin elevation should not provide false reassurance.

Do not delay PE workup. Even though pericarditis seems likely, PE carries extremely high maternal mortality and the presentations overlap substantially. Formal diagnostic assessment with validated methods is mandatory when PE is suspected in pregnancy 4.

Beware of lupus flare. Lupus pericarditis in pregnancy can cause massive effusions, heart failure, and requires aggressive immunosuppression 5, 7. If autoimmune markers are positive, multidisciplinary involvement (rheumatology, maternal-fetal medicine, cardiology) is essential.

Management Priorities

• Hemodynamic stability assessment - check for tamponade physiology
• Urgent PE exclusion with imaging as outlined above
• If PE excluded and pericarditis confirmed:
  • NSAIDs are relatively contraindicated in pregnancy (especially third trimester)
  • Colchicine is Category C and generally avoided
  • Corticosteroids may be necessary for symptomatic relief 8
  • Consider pericardiocentesis if hemodynamically significant effusion

Multidisciplinary pregnancy heart team involvement is recommended for complex cardiovascular conditions in pregnancy 4, particularly given the diagnostic uncertainty and potential need for invasive procedures or immunosuppression.