Arrhythmias USMLE Step 1 Practice Question
A 63-year-old man undergoes emergent percutaneous coronary intervention for anterior ST-elevation myocardial infarction. One hour post-procedure, telemetry shows a regular wide-complex rhythm at 75 bpm. Vital signs: BP 128/82 mmHg, HR 75, RR 16, SpO2 98% on room air. Troponin I is elevated at 8.2 ng/mL. He remains asymptomatic with no chest pain or dyspnea. Which of the following is the most likely explanation for this rhythm?
Answer choices
- AAtrial flutter with 2:1 conduction
- BTorsades de pointes due to prolonged QT
- CAccelerated idioventricular rhythm due to reperfusionCorrect answer
- DComplete heart block with junctional escape
- EMonomorphic ventricular tachycardia requiring immediate amiodarone
- FVentricular pacing artifact from a temporarily placed transvenous pacemaker
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