Detection of Epicardial Connection Through Intercaval Bundle Involving Right Pulmonary Veins After Ipsilateral Circumferential Ablation by Intra‐Atrial Activation Sequence Pacing From the Right Pulmonary Vein

An epicardial connection (EC) through the intercaval bundle (EC-ICB) between the right pulmonary vein (RPV) and right atrium (RA) is one of the reasons for the need for carina ablation for PV isolation and may reduce the acute and chronic success of PV isolation. We evaluated the intra-atrial activation sequence during RPV pacing after failure of ipsilateral RPV isolation and sought to identify specific conduction patterns in the presence of EC-ICB.