Successful catheter ablation of premature ventricular contractions originating from the anterior fascicle of the left bundle branch in a patient with hypertrophic cardiomyopathy

A 73-year-old man with hypertrophic cardiomyopathy was referred for an electrophysiologic study and catheter ablation of premature ventricular contractions (PVCs)/nonsustained ventricular tachycardia (NSVT). The QRS morphology of the PVCs was right bundle branch block with an inferior axis. Transthoracic echocardiography showed left ventricular hypertrophy and a normal left ventricular ejection fraction without any obstruction in the left ventricle (LV). Intracardiac mapping showed that the earliest activation site of the PVCs was within the anterior portion of the basal LV, where a Purkinje potential preceded the QRS onset by 32 ms. Radiofrequency application at that site terminated the PVCs. The PVCs/NSVT did not recur during 10 months of follow-up.