Arrhythmias USMLE Step 1 Practice Question
A 72-year-old woman presents with 3 days of fatigue and palpitations. Vital signs show BP 135/82 mmHg, HR 130/min, RR 18/min, temp 37.2°C, SpO2 98% on room air. ECG demonstrates atrial fibrillation with ventricular rate of 130/min. Troponin is normal. She denies chest pain or dyspnea. Currently takes metoprolol but reports poor adherence. Which of the following is the best initial pharmacologic goal?
Answer choices
- ASlow conduction through the AV nodeCorrect answer
- BIncrease sinus node discharge
- CStimulate alpha-1 receptors
- DBlock conduction through an accessory pathway
- EProlong ventricular repolarization in all patients
- FSuppress ectopic atrial foci responsible for maintaining the arrhythmia
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