P.3. Basic Science, Sudden Death Risk Stratification and Ventricular Arrhythmias

Verapamil-sensitive idiopathic ventricular tachycardia (IVT) has a clinical entity showing electrocardiographic features with left axis deviation and right bundle branch block. Sudden cardiac death is not usually associated with this IVT. We observed two cases that caused out-of-hospital ventricular fibrillation (VF). Case 1: 24 year-old-male was unconsciousness on a street. When paramedics arrived, ECG showed VF and beating was restored by defibrillation. After admission to intensive care unit, electrophysiological study (EPS) was performed. Both atrioventricular nodal reentrant tachycardia and IVT (cycle length=350ms) were induced by programmed stimulation, and radiofrequency ablation eliminated each tachycardia. 3 months later, EPS was done and it was impossible to induce both tachycardia and VF. Case 2: 68 year-old-male was admitted to hospital because of faintness caused by wide QRS tachycardia. EPS was performed. The final diagnosis was verapamil sensitive IVT (cycle length=240ms). As informed consent was not obtained, verapamil was orally given. Two years later, the patient experienced cardiopulmonary arrest at home and paramedics found VF on ECG. Although sinus rhythm was restored by defibrillation and the patient was admitted to intensive care unit, he died seven days after admission. On the basis of these two cases we can conclude that verapamil-sensitive IVT is not necessarily benign and an implantation of ICD may be useful.