Successful catheter ablation of unmappable monomorphic postinfarction ventricular tachycardia guided by a Purkinje...

We describe a case of a patient with the history of a monomorphic postinfarction ventricular tachycardia that exhibited a right bundle branch block morphology and a superior axis. Because of electrical and hemodynamic instability of arrhythmia, classical mapping techniques were not applied. An electroanatomic voltage map during sinus rhythm was performed. A Purkinje potential (PP) preceding the QRS complex was recorded at posteroseptal area of a scar. Radiofrequency energy delivery at sites where a PP was detected resulted in a successful ablation.