Favourable outcome in idiopathic ventricular fibrillation with treatment aimed at prevention of high sympathetic tone and suppression of inducible arrhythmias

Abstract

Objective: In the absence of an obvious cause for cardiac arrest, patients with idiopathic ventricular fibrillation are difficult to manage. A subset of patients has inducible arrhythmias. In others sympathetic excitation plays a role in the onset of the cardiac arrest. This study evaluates a prospective stepped care approach in the management of idiopathic ventricular fibrillation, with therapy first directed at induced arrhythmias and secondly at adrenergic trigger events. Setting: University Hospital. Patients: 10 consecutive patients successfully resuscitated from idiopathic ventricular fibrillation. Interventions: Programmed electrical stimulation to determine inducibility, followed by serial drug treatment. Assessment of pre-arrest physical activity and mental stress status by interview, followed by β blockade. Cardioverter-defibrillator implantation in noninducible patients not showing significant arrest related sympathetic excitation. Main outcome measure: Recurrent cardiac arrest or ventricular tachycardia. Results: Five patients were managed with serial drug treatment and four with β blockade. In one patient a defibrillator was implanted. During a median follow up of 2.8 years (range 6 to 112 months) no patient died or experienced defibrillator shocks. One patient had a recurrence of a well tolerated ventricular tachycardia on disopyramide. Conclusions: Idiopathic ventricular fibrillation may be related to enhanced sympathetic activation. Prognosis may be favourable irrespective of the method of treatment. Whether the present approach enhances prognosis of idiopathic ventricular fibrillation remains to be determined. However, it may help to avoid potentially hazardous antiarrhythmic drugs or obviate the need for implantation of cardioverter-defibrillators.