Arrhythmias USMLE Step 1 Practice Question
A 66-year-old man with anterior wall myocardial infarction presents with acute dizziness. Vital signs show BP 88/56, HR 42, RR 18, SpO2 98% on room air. ECG demonstrates wide QRS complexes with a constant PR interval on conducted beats and intermittent nonconducted P waves. Troponin elevation confirms acute MI. He denies chest pain currently. Which of the following is the most likely diagnosis?
Answer choices
- ASecond-degree AV block, Mobitz I
- BAtrial flutter
- CThird-degree AV block
- DSecond-degree AV block, Mobitz IICorrect answer
- EFirst-degree AV block
- FSinus bradycardia with ventricular ectopy
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