Arrhythmias USMLE Step 1 Practice Question
A 78-year-old man is brought to the emergency department because of recurrent syncope. Pulse is 32 per minute. ECG shows P waves occurring regularly at 80 per minute and QRS complexes occurring regularly at 30 per minute with no fixed relationship between them. Which of the following is the most likely diagnosis?
Answer choices
- ASecond-degree AV block, Mobitz I
- BJunctional tachycardia
- CSinus node dysfunction
- DThird-degree AV blockCorrect answer
- ESecond-degree AV block, Mobitz II
- FAtrial fibrillation with a slow ventricular response
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