Electrophysiological evaluation of pulmonary vein isolation.

Electrophysiologically demonstrated complete conduction block at the level of the veno-atrial junction is preferable as the endpoint of pulmonary vein (PV) ablation rather than circumferential periostial radiofrequency delivery. Knowledge of the individual anatomy of the PVs and the left atrium (LA), appropriate positioning of circular mapping catheters, and the electrophysiology of PV activation in addition to effective ablation tools is necessary to achieve this endpoint. Additional unnecessary ablation and possibly complications can be avoided by the recognition of non-PV myocardial contributions to PV electrograms. The posterior wall of the LA appendage contributes far-field electrograms to recordings from all left superior PVs (LSPV), the low lateral LA to 80% of left inferior PV (LIPV) recordings and the superior vena cava to 23% of right superior PV (RSPV) recordings. Each of these far-field components can be recognized in sinus rhythm as well as during ongoing atrial fibrillation. Finally, the creation of temporally stable and definitive PV isolation remains a currently unsolved problem.