OBJECTIVE To study the outcome of patients with arrhythmogenic right ventricular dysplasia treated with an implantable cardioverter-defibrillator (ICD) for ventricular tachyarrhythmias complicated by haemodynamic collapse.

DESIGN Observational study.

SETTING University hospital.

PATIENTS Nine consecutive patients (eight male, one female; mean (SD) age, 36 (18) years) with arrhythmogenic right ventricular dysplasia presenting with ventricular tachycardia and haemodynamic collapse (n = 6) or ventricular fibrillation (n = 3), treated with an ICD.

MAIN OUTCOME MEASURES Survival; numbers of and reasons for appropriate and inappropriate ICD interventions.

RESULTS After a mean (SD) follow up of 32 (24) months, all patients were alive. Six patients received a median of 19 (range 2–306) appropriate ICD interventions for events detected in the ventricular tachycardia window; four received a median of 2 (range 1–19) appropriate ICD interventions for events detected in the ventricular fibrillation window. Inappropriate interventions were seen for sinus tachycardia (18 episodes in three patients), atrial fibrillation (three episodes in one patient), and for non-sustained polymorphic ventricular tachycardia (one episode in one patient).

CONCLUSIONS Patients with arrhythmogenic right ventricular dysplasia and malignant ventricular arrhythmias have a high recurrence rate requiring appropriate ICD interventions, but they also often have inappropriate interventions. Programming the device is difficult because this population develops supraventricular and ventricular tachyarrhythmias with similar rates.