We report the case of a 19-year-old male who successfully recovered from sudden cardiac arrest. Careful evaluation did not reveal any electrical or structural abnormalities. He underwent implantable cardioverter defibrillator (ICD) implantation, with a diagnosis of idiopathic ventricular fibrillation (VF). Three months later, VF recurred and was successfully terminated by ICD shock. Electrocardiogram (ECG) revealed a slurred type J point elevation at the inferolateral leads with a horizontal/descending ST segment change, which was not present during the initial hospitalization. Cilostazol was prescribed to prevent further lethal ventricular arrhythmias. Subsequently, no arrhythmic events were reported, and the J wave disappeared at the follow-up ECG. However, recurrent VF episodes with an interval of 1–2 weeks occurred 1 year later, and were terminated by ICD shock. Simultaneous ECG revealed a J point elevation at the inferolateral leads. Cilostazol was replaced by quinidine. Subsequently, no arrhythmic event recurred for over 12 months. Serial follow-up ECG is needed to identify masked inherited primary arrhythmic syndromes in sudden cardiac arrest survivors diagnosed with idiopathic VF. Cilostazol and quinidine might be good therapeutic options to prevent further lethal events in cases where the J wave syndrome is present with recurrent ventricular arrhythmias.