The advent of radiofrequency (RF) ablation has transformed electrophysiological practice in the past 10 years. RF ablation is now considered first line treatment for many supraventricular arrhythmias. Buoyed by this success the eager ablator has turned to ventricular tachycardia (VT).

The first ventricular arrhythmias to fall convincingly to RF ablation were the focal VTs occurring in patients without evidence of structural heart disease1; 70% arise in the ventricular outflow tract, usually the septal surface of the right ventricular outflow tract. This arrhythmia is typically catecholamine dependent, adenosine sensitive, and probably caused by cyclic AMP mediated triggered activity.2 ,3 The usual clinical picture is of a young woman with symptomatic ectopic beats of left bundle and inferior axis morphology and with non-sustained VT on exercise (fig 1).4Success rates for RF ablation in this condition are more than 90%.

Occasionally, VT may arise in the left ventricular outflow tract or the epicardial right ventricular outflow tract and must be approached differently.5 Left septal (fascicular) VT (fig 2 …