Limitations
First, our sample size was small, which thus requires validation by large-scale studies to prove the findings of the present study. Second, a possibility of far-field capture of the RPV carina by RAPW pacing was observed that may have affected the main results of this study. However, the conduction time between the RAPW pacing stimulus and the RPV carina in the EC group was not short (48.5 ± 12 ms) and far-field capture of the RPV carina is unlikely. Lastly, conduction regarding the ligament of Marshall and the left PVs was not evaluated in the present study, because assessment of the vein of Marshall is difficult. It cannot be determined whether age or epicardial fatty tissue is involved in this conduction.