What is the evaluation and management of chest pain and shortness of breath (dyspnea) in a 26-year-old pregnant woman?

Evaluation and Management of Chest Pain and Shortness of Breath in a 26-Year-Old Pregnant Woman

A pregnant woman with chest pain and shortness of breath requires immediate evaluation for life-threatening conditions including pulmonary embolism, acute coronary syndrome, and aortic dissection, with diagnostic testing that balances maternal safety and fetal radiation exposure. 1, 2

Initial Assessment

Critical Signs Requiring Immediate Attention

• Vital signs: Check for tachycardia, hypotension, tachypnea, hypoxemia
• Maternal early warning criteria 1:
  • Systolic BP <90 or >160 mmHg
  • Diastolic BP >100 mmHg
  • Heart rate <50 or >130 bpm
  • Oxygen saturation <95% on room air
  • Changed mental status
  • Non-remitting headache in hypertensive patients

Key Diagnostic Tests

1. ECG - Must be obtained and reviewed within 10 minutes of arrival 1
2. Arterial blood gases - To assess hypoxemia and acid-base status
3. D-dimer testing - Has same exclusion value for PE in pregnant as non-pregnant patients 2
4. Chest X-ray - First radiation-associated test (minimal exposure of 0.01 mSv) 2
5. Laboratory tests 1:
   • Complete blood count
   • Cardiac troponin
   • Serum creatinine, electrolytes
   • Coagulation profile

Differential Diagnosis

Life-Threatening Causes

1. Pulmonary Embolism (PE)

   • Common symptoms: pleuritic chest pain (55%), cough (24%), sweating (18%) 2
   • Physical findings: tachycardia and dyspnea in >90% of patients 1

2. Acute Coronary Syndrome (ACS)

   • Rare but increasing in pregnancy (3-6 per 100,000 deliveries) 1
   • Risk factors: smoking, hypertension, hyperlipidemia, diabetes, family history
   • Pregnancy-specific risk factors: (pre)eclampsia, thrombophilia, peripartum period 1

3. Aortic Dissection

   • Signs: severe pain with abrupt onset, pulse differential, widened mediastinum on CXR 1
   • Risk factors: connective tissue disorders (e.g., Marfan syndrome) 1

4. Hypertensive Emergency

   • Risk factors: pre-eclampsia, cardiac disease, chronic renal disease 1
   • Warning signs: severe chest pain, persistent excessive shortness of breath 1

Other Causes

• Pneumonia - fever, localized chest pain, regional dullness to percussion 1
• Pneumothorax - dyspnea and pain on inspiration, unilateral absence of breath sounds 1
• Pericarditis - fever, pleuritic chest pain increased in supine position, friction rub 1
• Myocarditis - fever, chest pain, heart failure signs 1
• Physiologic dyspnea of pregnancy - rule of exclusion after other causes eliminated

Diagnostic Imaging Algorithm

1. If signs/symptoms of DVT present:

   • Perform lower extremity compression ultrasound first 2
   • If positive, start anticoagulation without further imaging

2. If PE suspected and patient stable:

   • Begin with D-dimer testing 2
   • If D-dimer negative, PE can be excluded
   • If D-dimer positive or not performed, proceed to imaging

3. Imaging for suspected PE:

   • CTPA is preferred with fetal radiation exposure of only 0.003-0.02 mSv 2
   • Optimize protocol: proper hydration, high iodine flux (4.5-6 ml/s), automated bolus triggering 2
   • V/Q scan is an alternative if CTPA unavailable or contraindicated
   • Use half the usual administered activity of Tc-99m for V/Q scan 2

4. For suspected ACS:

   • Echocardiography to evaluate wall motion abnormalities 1
   • If unstable with ACS, refer immediately for coronary angiography and primary PCI 1

Management Principles

For Suspected PE

• If clinical suspicion is high and bleeding risk low, initiate anticoagulation while awaiting diagnostic results 2
• For hemodynamically unstable patients, start IV unfractionated heparin immediately 2
• Bedside echocardiography should be performed to assess for right ventricular dysfunction 2

For Suspected ACS

• Refer immediately to a skilled intervention center for diagnostic angiogram and primary PCI if ST-elevation ACS 1
• Avoid ergometrine for post-partum bleeding as it may lead to coronary vasospasm 1

For Severe Shortness of Breath

• Stop physical activity immediately and consult healthcare provider 1
• Avoid activities in excessive heat or high humidity 1
• Maintain adequate hydration before, during, and after physical activity 1

Important Caveats

1. Do not withhold appropriate imaging due to pregnancy concerns - The risk of missing a life-threatening diagnosis outweighs the minimal radiation risk to the fetus 2, 3

2. Pregnancy may mask or mimic cardiac conditions - Pregnant women with significant SOB may have subtle cardiac involvement even with normal pregnancy 4

3. Consider pregnancy-specific causes - Pre-eclampsia, peripartum cardiomyopathy, and amniotic fluid embolism should be considered 5

4. Multidisciplinary approach - Involve maternal-fetal medicine specialists, cardiologists, and emergency physicians in complex cases 2

By following this structured approach, clinicians can effectively evaluate and manage chest pain and shortness of breath in pregnant women while minimizing risks to both mother and fetus.