Evaluating Pulmonary Vein Isolation

Pulmonary vein isolation is the electrophysiological endpoint of complete conduction block at the level of the veno‐atrial junction and must be explicitly distinguished from encircling PV ablation which frequently does not result in isolation. The prerequisites for successful PV isolation include a knowledge of the individual anatomy of the PVs and the left atrium, appropriate positioning of circular mapping catheters, and a knowledge of the electrophysiology of PV activation, in addition to effective ablation tools. Excessive ablation, and possibly complications, can be avoided by the recognition of non‐PV myocardial contributions to electrograms recorded from within the PVs. The posterior wall of the left atrial appendage contributes far‐field electrograms to recordings from all or nearly all left superior PVs, the low anterior left atrium to 80% of left inferior PV recordings and the superior vena cava to 23% of right superior PV recordings. Recognition of these far‐field components is feasible and accurate in sinus rhythm as well as during ongoing atrial fibrillation. Finally, the creation of temporally stable PV isolation remains a currently unsolved problem although prolonged post isolation surveillance, may be helpful.