Intraseptal Mapping of Premature Ventricular Complexes Using Multipolar Catheters

BACKGROUND: Intramyocardial mapping of left ventricular outflow tract (LVOT) premature ventricular complexes (PVCs) via septal coronary venous branches is helpful to define the site of origin (SOO) and guide ablation. The limitation of unipolar far-field signals with wire mapping can be obviated through the use of a multipolar mapping catheter. OBJECTIVES: This study reports our mapping and ablation experience of suspected LVOT PVCs using intraseptal mapping with multipolar catheters. METHODS: , respectively. Endocardial, intramyocardial, or epicardial SOO was based on activation pattern. RESULTS: R-wave PB ratio <1.0 ruled out an endocardial source. Acute ablation success was achieved in 98% and freedom from recurrence was 93% at a median follow-up of 12.4 months. Recording of intraseptal late potentials with reversal during PVC was observed in 25 (42%) patients and was associated with long-term success. CONCLUSIONS: Ablation of LVOT PVCs guided by intraseptal mapping using multipolar catheters is feasible and highly effective. Electrocardiogram predictors of SOO identify patients in whom intraseptal mapping may be useful. Reversal of late potentials with PVCs may represent abnormal substrate in idiopathic PVCs in ostensibly structurally normal hearts.