Arrhythmias USMLE Step 1 Practice Question
A 60-year-old man with a history of hypertension presents after sudden collapse following severe substernal chest pain. On arrival, he is unresponsive and pulseless with BP unrecordable, HR unmeasurable, RR 0, and SpO2 undetectable. Cardiac monitor displays chaotic, irregular deflections without organized QRS complexes. Troponin is elevated at 2.8 ng/mL. There is no evidence of pulmonary edema on examination. He takes no anticoagulation therapy. Which rhythm is most likely present?
Answer choices
- AThird-degree AV block
- BAtrial fibrillation
- CVentricular fibrillationCorrect answer
- DPulseless electrical activity
- EAsystole
- FPolymorphic ventricular tachycardia
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