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Asymptomatic Nocturnal Pauses — EECC MCQ

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ModerateGeneral CardiologyAsymptomatic Nocturnal PausesEECC

A 60-year-old man with HCM and an implanted loop recorder (ILR) has two 4-second pauses detected during sleep. He is asymptomatic. Are these pauses clinically significant?

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Correct answer: D — Asymptomatic nocturnal pauses up to 3-6 seconds can be physiological due to high vagal tone during sleep and do not necessarily indicate sinus node disease; clinical significance requires symptom-rhythm correlation

The interpretation of bradycardia and pauses on continuous monitoring (ILR, Holter) requires clinical context. The ESC 2021 Pacing Guidelines note: (1) nocturnal sinus pauses up to 3 seconds are common and may be physiological (vagal tone); (2) asymptomatic pauses up to 6 seconds during sleep in young/athletic individuals may be benign; (3) pacing is indicated (Class I) for symptomatic sinus node dysfunction with documented bradycardia-symptom correlation. In HCM specifically, sinus node dysfunction can occur, but asymptomatic nocturnal pauses in a patient with high vagal tone (often enhanced by beta-blocker therapy) do not mandate pacing. If pauses are occurring during wakefulness or are associated with presyncope/syncope, further evaluation and pacing are warranted.

Reference: ESC (2021): Pacing Guidelines