Arrhythmias USMLE Step 1 Practice Question
A 27-year-old pregnant woman at 24 weeks gestation presents with sudden palpitations and diaphoresis. Vital signs show BP 118/76 mmHg, HR 185/min, RR 20/min, SpO2 98% on room air. ECG demonstrates a regular narrow-complex tachycardia at 185 bpm with no evidence of delta waves. Troponin is normal. She denies chest pain and lung auscultation is clear bilaterally. She takes only prenatal vitamins. Which of the following is the best initial step after obtaining the ECG?
Answer choices
- AIntravenous procainamide before any bedside maneuvers
- BVagal maneuversCorrect answer
- CImmediate unsynchronized defibrillation
- DPermanent pacemaker placement
- ENo treatment because pregnancy protects against recurrence
- FImmediate electrical cardioversion as first-line therapy for SVT in pregnancy
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