A physician-validated, board-style question from the Active Transport QBank. Try it, then check the reasoning for every option.
A 68-year-old man presents with dizziness and episodes of confusion over the past several weeks. He reports no chest pain, palpitations, or shortness of breath. His pulse is 54/min, blood pressure is 130/80 mmHg, and ECG reveals a sinus bradycardia with a rate of 50/min. Laboratory tests show normal thyroid function and electrolytes. Further ambulatory ECG monitoring shows frequent sinus pauses greater than 3 seconds. Which of the following is the most appropriate definitive treatment for this patient's condition?
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A
Transcutaneous pacingIncorrect. Transcutaneous pacing is temporary bridge therapy, not definitive treatment for chronic sick sinus syndrome.
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B
Permanent pacemaker implantationCorrect. Symptomatic sinus pauses greater than 3 seconds from sick sinus syndrome require permanent pacemaker implantation.
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C
Oral beta-blocker therapyIncorrect. Beta-blockers slow the SA node and would worsen symptomatic bradycardia and pauses.
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D
Observation and follow-upIncorrect. Observation is inadequate given symptomatic confusion, dizziness, and documented pathologic pauses on monitoring.
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E
Intravenous atropine administrationIncorrect. Atropine acutely reverses vagally mediated bradycardia, not chronic intrinsic SA node dysfunction.
↑ Tap an answer to reveal the reasoning
Answer: B. The vignette describes a classic case of sick sinus syndrome with symptomatic sinus bradycardia and pauses. The definitive treatment for symptomatic intrinsic SA node dysfunction is permanent pacemaker implantation. Beta-blockers would worsen bradycardia, while atropine is for acute management. Transcutaneous pacing is temporary, and observation is insufficient given the symptoms.