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Device-detected Subclinical AF — EECC MCQ

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HardArrhythmia & ElectrophysiologyDevice-detected Subclinical AFEECC

A 72-year-old woman with a dual-chamber pacemaker (DDD) for sick sinus syndrome develops AF detected on device interrogation. The device shows an atrial high-rate episode (AHRE) lasting 4 hours. She has a CHA₂DS₂-VA score of 3 but has never had clinical AF or symptoms. Should anticoagulation be started?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: D — Anticoagulation should be considered (Class IIa) for device-detected AHRE ≥24 hours with CHA₂DS₂-VA ≥2; for episodes of 5 minutes to 24 hours, the decision is less clear and requires individual risk assessment

This is device-detected subclinical AF/AHRE, not previously documented clinical AF. AHREs should not be ignored, but anticoagulation is not automatic for every episode. The key determinants are confirmation that the stored electrogram represents true atrial arrhythmia, AHRE duration/burden, thromboembolic risk and bleeding risk. For AHRE lasting ≥24 hours in a patient with elevated stroke risk, anticoagulation should be considered. For shorter episodes lasting 5 minutes to 24 hours, such as this patient’s 4-hour AHRE, the net benefit is less certain and the decision should be individualised, with shared decision-making and follow-up for progression to clinical or higher-burden AF. Therefore the correct answer is D.

Reference: 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation, section 6.4.1: Oral anticoagulation for device-detected atrial high-rate episodes among patients without a previous diagnosis of AF. https://www.ahajournals.org/doi/10.1161/CIR.0000000000001193