Ventricular Tachycardia in Patients With Normal Hearts

Abstract

Ventricular tachycardia or ventricular fibrillation can occur in patients with structurally normal hearts. Up to 10% of patients with ventricular tachycardia may have a structurally normal heart. The incidence of idiopathic ventricular fibrillation is less well defined. The prognosis in patients with idiopathic ventricular tachycardia is generally good, but some patients may have a more malignant course with syncope or even rare sudden death. The majority of ventricular tachycardias in patients with structurally normal hearts arise from the right ventricular outflow tract, but up to one-third of these ventricular tachycardias may arise from other right or left ventricular sites. The mechanism of these arrhythmias is not well understood and may be multifactorial, including triggered activity, abnormal automaticity, and reentry. Some left ventricular tachycardias are fascicular tachycardias. Treatment of idiopathic ventricular tachycardia is recommended for symptomatic patients; various therapeutic strategies are reviewed in this article. Catheter ablation appears to be very promising therapy and may be curative in over 90% of patients. In fact, radiofrequency catheter ablation as therapy for symptomatic idiopathic ventricular tachycardia is rapidly becoming early therapy in patients refractory to or intolerant of beta-blockers or calcium channel blockers. (Cardiol Rev 1993;1:6, 336-343)