Life threatening ventricular arrhythmias in patients with minimal or no structural heart disease: Experience with the implantable cardioverter defibrillator

Limited data exist about prognosis and appropriate treatment of life threatening ventricular arrhythmias in patients with no or minimal heart disease. In this study we report on a series of patients who suffered sudden cardiac death of syncope due to documented ventricular tachycardia (VT) or fibrillation (VF) and in whom no significant organic or metabolic heart disease was found after detailed diagnostic studies. All patients undergone an electrophysiologic study (EPS) and subsequently were treated with an automatic implantable cardioverter defibrillator (ICD). They were followed up for arrhythmia recurrence and ICD shock. Nine patients were included (5 female) with a mean age of 35,3+ 8.5 years. Mean left ventricular ejection fraction was 74%. On EPS four patients (45%) had inducible sustained monomorphic VT (SMVT) and two developed polymorphic VT degenerated into VF. Eight ICD shocks were encountered during follow up (27.3+8.7 months). Seven of them considered appropriate and distributed in three patients. Shock free survival was 75% after one year and 63% after two years. Inducibility of SMVT correlated with the greater chance of receiving an appropriate shock (p=0.047). These findings suggest a high recurrence rate of symptomatic and sustained idiopathic ventricular arrhythmias and prove that ICD treatment is effective and safe. Patients in whom SMVT is inducible have most benefit from it.