What is the appropriate workup for a pregnant patient presenting with chest pain?

Workup for Chest Pain in Pregnancy

Begin with immediate risk stratification to identify life-threatening cardiovascular emergencies—pulmonary embolism, acute coronary syndrome, and aortic dissection—which account for the majority of pregnancy-related cardiac deaths and require urgent diagnostic imaging that should never be withheld due to pregnancy status. 1, 2

Initial Clinical Assessment

Red Flag Symptoms Requiring Emergency Evaluation

• Severe chest pain, particularly pleuritic in nature, requires immediate workup as it may indicate pulmonary embolism, the leading cause of pregnancy-related maternal death in developed countries (20% of maternal deaths, incidence 1 per 1000-3000 deliveries). 1, 2

• Severe dyspnea at rest (not just exertional), syncope/presyncope, hemoptysis, or palpitations with unexplained hypotension mandate urgent evaluation for cardiovascular emergencies. 1, 3

• Sudden-onset "ripping" chest pain radiating to the back should raise immediate concern for aortic dissection. 3

• Diaphoresis, tachycardia, hypotension, or chest pain with documented sustained tachycardia require evaluation for acute coronary syndrome, which carries 5-10% maternal mortality. 1, 3

Physical Examination Priorities

• Perform focused cardiovascular examination assessing for pulse differentials (aortic dissection), unilateral decreased breath sounds (pneumothorax/PE), cardiac murmurs, signs of heart failure (S3, crackles), and extremity edema/tenderness (DVT). 4

• Document vital signs recognizing that heart rate increases 10-20 bpm in pregnancy (particularly third trimester) and blood pressure may decrease 10-15 mmHg by 20 weeks, but respiratory rate and oxygen saturation remain unchanged. 4

Diagnostic Algorithm

Step 1: Initial Testing for All Patients with Concerning Chest Pain

• Obtain 12-lead ECG immediately to assess for ischemic changes (ST-segment depression has specificity 95%, LR 5.3), arrhythmias, or prolonged QT interval. 3, 5

• Measure cardiac biomarkers (troponin I) if acute coronary syndrome is suspected, recognizing that troponin is not elevated in normal pregnancy but may be elevated in pre-eclampsia, PE, myocarditis, or arrhythmias. 4, 3

• Obtain chest radiograph (rating 9/9 "usually appropriate" by ACR) as the initial imaging study for all pregnant patients with suspected PE or other chest pathology. 4

• Do NOT use D-dimer testing as it has inadequate sensitivity (73%) and specificity (15%) for excluding PE in pregnancy, with documented false negatives in pregnant women with confirmed PE. 4, 3

Step 2: Workup for Suspected Pulmonary Embolism

If clinical suspicion for PE exists (dyspnea, pleuritic chest pain, tachycardia, hypoxemia):

• Perform bilateral lower extremity duplex ultrasound first (rating 8/9 "usually appropriate") as this may prevent need for ionizing radiation if DVT is confirmed, since 80% of PEs are associated with DVT. 4, 2

• If lower extremity ultrasound is negative or not indicated, proceed with either:

  • CT pulmonary angiography (CTPA) optimized for pulmonary circulation (rating 7/9 "usually appropriate"), OR
  • Ventilation-perfusion (V/Q) scintigraphy (rating 7/9 "usually appropriate," perform ventilation only if necessary). 4, 2

• The choice between CTPA and V/Q scan should be based on local expertise and chest radiograph findings, but both are acceptable and should not both be performed. 4

• Maternal mortality risk far outweighs fetal radiation risk, especially outside the first trimester, and diagnostic imaging should never be delayed. 2

Step 3: Workup for Suspected Acute Coronary Syndrome

If ACS is suspected (severe chest pain, ECG changes, elevated troponin):

• Proceed directly to diagnostic coronary angiography without delay, as this directly visualizes spontaneous coronary artery dissection (the most common cause of pregnancy-associated ACS) and significantly improves survival. 1, 2

• Spontaneous coronary artery dissection occurs predominantly peripartum due to progesterone-induced collagen changes in vessel walls and is more prevalent in pregnant than non-pregnant women. 2, 3

• Risk factors include smoking, hypertension, hyperlipidemia, older maternal age, diabetes, and positive family history. 3

Step 4: Additional Diagnostic Studies

• Perform echocardiography for unexplained or new cardiovascular signs/symptoms, to evaluate wall motion abnormalities, structural disease, and to assess for aortic dissection. 4, 3

• Obtain thyroid function tests if tachycardia is present without other clear etiology. 3

• Consider arterial blood gas recognizing that mild, fully compensated respiratory alkalosis is normal during pregnancy. 4

Common Pitfalls to Avoid

• Do not attribute all dyspnea and tachycardia to normal pregnancy physiology, as this leads to missed diagnoses of life-threatening conditions. Mild exertional dyspnea with normal examination may be physiologic, but severe dyspnea at rest is never normal. 1

• Do not delay imaging due to radiation concerns, as maternal mortality from undiagnosed PE or ACS far exceeds fetal radiation risk. 2

• Do not rely on D-dimer to exclude PE in pregnancy due to documented false negatives. 4, 3

• Do not assume chest pain is gastroesophageal reflux (though common in pregnancy) without first excluding cardiovascular emergencies, particularly if pain is severe, persistent, or accompanied by other concerning features. 3

• Recognize that normal pregnancy does not elevate BNP or troponin, so elevated values indicate pathology. 4