Total electrical isolation of all 4 PVs compared with electrical isolation of only PV(s) where abnormal impulses are found should be more efficacious in achieving long-term cure of patients undergoing ablation for AF. Furthermore, the saline irrigated cooled tip catheter should be able to accomplish successful EI of PV(s) in either group with lesser number of lesions when compared with the standard 4-mm tip or 8-mm tip ablation catheter.