What is the next step for a 17-week pregnant woman reporting chest pain?

Immediate Assessment for Life-Threatening Causes

A 17-week pregnant woman with chest pain requires immediate evaluation for life-threatening conditions including pulmonary embolism, acute coronary syndrome, and aortic dissection, with ECG obtained within 5 minutes and vital signs assessed immediately. 1

Critical Initial Steps

Obtain ECG within 5 minutes of presentation to identify ST-segment elevation, ST-segment depression, T-wave inversions, or new Q waves that would suggest acute coronary syndrome. 1 This is non-negotiable regardless of the patient's age or perceived low risk, as pregnancy itself increases thrombotic risk and spontaneous coronary artery dissection is more prevalent during pregnancy. 2, 1

Assess vital signs immediately looking specifically for:

• Severe tachycardia beyond normal pregnancy-related increases 3, 1
• Hypoxemia (SpO2 <95%) 4, 3
• Unexplained hypotension 3, 1
• Tachypnea, particularly respiratory rate >35/min which mandates ICU transfer 4

Red Flag Symptoms Requiring Urgent Workup

Stop and seek immediate medical attention if any of these features are present, as they indicate potentially catastrophic conditions 2:

• Severe chest pain - particularly if sudden, ripping, or "worst pain of life" suggesting aortic dissection 2, 1
• Pleuritic chest pain (sharp, worsening with breathing) - present in 55% of pregnancy-related pulmonary embolism cases 3
• Dyspnea at rest or severe dyspnea - occurs in 62% of confirmed PE cases and is a leading cause of maternal death 3, 1
• Syncope or presyncope 3, 1
• Hemoptysis 3

Diagnostic Testing Priority

High-sensitivity troponin I should be obtained as the preferred biomarker for acute myocardial infarction, with elevated levels prompting consideration of ischemic heart disease even in young patients. 1 Pregnancy-related acute coronary syndrome carries 5-10% maternal mortality. 2, 1

Do not rely on D-dimer alone to exclude pulmonary embolism, as it has only 73% sensitivity in pregnancy with documented false negatives in confirmed PE cases. 3 However, it can help with risk stratification when interpreted in clinical context. 1

Chest X-ray should be performed as initial imaging for suspected PE with minimal radiation exposure. 1 Pregnant patients are significantly less likely to undergo radiography compared to non-pregnant patients, which could delay diagnosis and treatment. 5

Imaging Approach for Suspected PE

If pulmonary embolism remains suspected after initial workup:

1. Lower extremity venous duplex ultrasound first - no radiation exposure, and DVT detection allows treatment without further imaging 4, 1
2. CT pulmonary angiography (CTPA) if ultrasound negative but suspicion remains high - optimized for pulmonary circulation 1
3. Arterial blood gas in upright position if performed, as supine position can lower PaO2 by up to 2 kPa in late pregnancy 4

Management During Workup

Initiate empiric anticoagulation in hemodynamically stable patients with high clinical suspicion for PE while diagnostic workup proceeds. 4 Pulmonary embolism accounts for 20% of maternal deaths in the United States. 1

Provide supplemental oxygen to maintain SpO2 >95%, as pregnant patients develop hypoxemia rapidly due to decreased functional residual capacity and increased oxygen demand. 4

Avoid dismissing symptoms as "normal pregnancy" - no individual clinical feature reliably predicts or excludes PE in pregnancy, making clinical judgment crucial. 3 The consequences of missing PE far outweigh the risks of diagnostic imaging. 3

When to Involve Specialists Immediately

Multidisciplinary team involvement is mandatory for unstable patients, including obstetric anesthesia, obstetrics, cardiology, pulmonology, and intensive care as appropriate. 4

Refer immediately to skilled intervention center if ST-elevation ACS is identified, for diagnostic angiogram and primary PCI rather than thrombolysis. 2 Coronary angiography with PCI is preferred as it will also diagnose coronary artery dissection, which is more prevalent in pregnancy especially peripartum. 2, 1

Common Pitfalls to Avoid

• Do not withhold radiography from pregnant patients based on radiation concerns - with few exceptions, necessary imaging should not be delayed. 5
• Do not use nitroglycerin response as a diagnostic criterion for cardiac ischemia, as relief is not specific to myocardial ischemia. 2
• Do not perform exercise or nuclear stress testing due to radiation exposure. 1
• Maintain high index of suspicion even with normal vital signs, as many normal pregnancy symptoms overlap with serious conditions. 3