Idiopathic premature ventricular contractions arising from the pulmonary artery importance of mapping in the pulmonary artery in left bundle branch block-shaped ventricular arrhythmias

A patient underwent radiofrequency (RF) catheter ablation of symptomatic idiopathic ventricular contractions (PVCs). RF energy applications at 2 sites in the right ventricular outflow tract (RVOT), where both the earliest ventricular activation and near-perfect pace mapping were obtained, did not abolish the PVC but resulted in changes in the QRS morphology of the PVC. Complete elimination of the PVC was achieved with RF energy application at a site within the pulmonary artery 13 mm above the pulmonary valve, which was greater than 20mm away from the failed ablation sites within the RVOT.