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Idiopathic VF — EECC MCQ

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ModerateArrhythmia & ElectrophysiologyIdiopathic VFEECC

A 50-year-old man with no cardiac history presents with sudden cardiac arrest. He is resuscitated from VF. All investigations (coronary angiography, CMR, genetic testing, drug screen) are negative. What is the diagnosis?

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Correct answer: E — Idiopathic ventricular fibrillation (IVF) — defined as VF cardiac arrest without identifiable structural, electrical, or metabolic cause after comprehensive evaluation; ICD implantation is mandatory (Class I) as a secondary prevention measure

Idiopathic VF is diagnosed when all known causes of cardiac arrest have been excluded through comprehensive evaluation: (1) coronary angiography (exclude ACS); (2) CMR (exclude cardiomyopathy, myocarditis); (3) resting and exercise ECG (exclude channelopathies — Brugada, LQTS, SQTS, CPVT); (4) genetic testing (comprehensive arrhythmia gene panel); (5) provocation testing (ajmaline challenge for Brugada, exercise test for CPVT); (6) drug/toxin screen. IVF accounts for approximately 5-10% of out-of-hospital cardiac arrest survivors after comprehensive workup. The ESC 2022 VA/SCD Guidelines recommend: (1) ICD implantation (Class I — secondary prevention); (2) consider quinidine or isoproterenol for VF storm; (3) catheter ablation of triggering PVCs if identified (often from Purkinje fibres). Family screening is recommended as some cases represent undiagnosed inherited conditions.

Reference: ESC (2022): VA/SCD Guidelines