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Successful catheter ablation of symptomatic premature ventricular contractions originating from mitral annulus.

A 20-year-old male patient was admitted to our department with the complaint of palpitation. He had been having palpitations for 4 years. Medical treatment with calcium channel blocker and beta-blocker was unsuccessful. Physical examination of cardiovascular and other systems was normal. Resting electrocardiogram (ECG) showed PVCs with a right bundle branch block morphology and inferior axis (Fig.1). QRS notching was observed in the inferior leads of the PVCs. Exercise ECG and transthoracic echocardiography were within the normal range. The monomorphic PVCs (8000 beats/day) were detected in Holter ECG. Electrophysiological study was performed. Programmed ventricular stimulation did not induce ventricular tachycardia. Electrophysiological mapping was performed during PVCs. During PVC, the earliest ventricular activation was seen in the distal electrode of the coronary sinus. After placing the steerable 4-mm-tip ablation catheter (Mariner; Medtronic,. Minneapolis, MN, USA) to the left ventricle with retrograde aortic approach, mapping of the aortic cusps and left ventricle outflow tract was performed. Early activation site was not detected at the aortic cusp and left ventricle outflow tract. With left ventricular mapping, earliest ventricular activity during PVCs was recorded in the anterolateral of the mitral annulus. In this site during the PVC, local ventricular activation preceded the QRS onset by 28 ms (Fig. 2). Radiofrequency ablation applied to this site and PVCs disappeared (Fig. 3). PVCs were not observed during follow-up examinations at second month.