Clinical manifestations and outcomes of idiopathic ventricular fibrillation and early repolarization syndrome in adolescents: A multicenter cohort study

Abstract

BACKGROUND Idiopathic ventricular fibrillation (IVF) and early repolarization syndrome (ERS) are rare but potentially life-threatening arrhythmias. Their clinical distinction is often challenging and prognostic factors remain unclear, particularly in adolescents. OBJECTIVE This study compared clinical outcomes and electrocardiographic (ECG) characteristics of adolescents with IVF and ERS to identify disease-specific prognostic factors. METHODS Patients diagnosed as having IVF or ERS between 2000 and 2022 were retrospectively reviewed from a nationwide Korean multicenter cohort of pediatric inherited arrhythmia syndromes. ECGs were systematically reanalyzed for early repolarization patterns (ERPs). Life-threatening arrhythmic events (LAEs), including ventricular arrhythmias, appropriate implantable cardioverter-defibrillator shock, and sudden cardiac arrest, were compared between the groups. RESULTS ECG reanalysis led to the reclassification of 10 patients from IVF to ERS, resulting in 14 patients with ERS and 25 patients with IVF (mean age 16.0 6 2.3; 92.3% male). LAEs were more frequent in the ERS group (92.9% vs 52.0%; P = .025), with shorter LAE-free survival (median 7.2 vs 51.6 months; P = .005). In ERS, inferolateral ERP predicted poorer prognosis than inferior ERP (hazard ratio 9.29 [1.68-101.36]; P = .009), whereas coexistence ofsupraventriculartachycardia was a risk factor for LAEs in IVF (hazard ratio 7.24 [1.89-29.73]; P = .005). J-wave duration was longer in inferolateral ERP and in cases with pause-dependent augmentation. CONCLUSION IVF and ERS have distinct prognoses and risk factors in adolescent patients. ECG-based differentiation and identification of prognostic factors may guide individualized strategies.