Selective Proximal Left Anterior Fascicle Pacemapping for Guiding narrow QRS Premature Ventricular Complex ablation from the Right Coronary Cusp

Premature ventricular complexes (PVC) ablation has increased over the past decades. The morphology of PVCs arising from left anterior fascicle (LAF) is typically a right bundle branch block-like morphology with an inferior axis showing a qR or qRs complex in the inferior leads and an rS or RS complex in leads I and aVL. We describe the case of a 38 years old woman with symptomatic, high burden PVCs, despite of beta blockers treatment. The PVC’s ECG morphology suggested an origin in the LAF. This case illustrates how ablation from the right coronary cusp for PVC arising from the LAF could be accurately guided by pace-mapping. At this location, pacing at different outputs can result in both a selective and a non-selective capture of the left anterior fascicle.