Persistent ventricular tachycardia resulting in left ventricular dilatation treated with verapamil.

A case with a verapamil-sensitive ventricular tachycardia showing right bundle branch block pattern and left axis deviation is described. Electrophysiological evaluation revealed features compatible with previous suggestions of posterior fascicular origin for this unique type of arrhythmia. In contrast to being paroxysmal, as is usually the case, the tachycardia was persistent and led to cardiac enlargement, which was completely reverted following successful treatment with verapamil.