Risk Assessment and Pharmacological Effect in Patients with J Waves and Idiopathic Ventricular Fibrillation

22 patients with idiopathic ventricular fibrillation (IVF) (mean age 36±13, 17 male) and 6,657 healthy controls (mean age 45±22, 3,399 male) for risk assessment; 7 young IVF patients (mean age 23±8, 6 male) for pharmacological evaluation.

Beta-blockers or Class III antiarrhythmic drugs (for the pharmacological evaluation cohort)

Healthy controls (for risk assessment); no comparator for pharmacological evaluation

Detection of late potentials (LP), T-wave alternans (TWA), QT dispersion, and frequency-domain heart rate variability; prevention of VF/syncopesurrogate