A quantitative comparison of the electrical and anatomical definition of the pulmonary vein ostium.

BACKGROUND: Anatomically guided pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. However, the position where to confirm electrical isolation is ill-defined. The aim of the current study was to quantify the relationship between the anatomical and electrical definition of the pulmonary vein ostium.

METHODS: We analyzed 20 patients with paroxysmal AF undergoing PVI using radiofrequency energy and an electroanatomical mapping system. The anatomical ostium was defined based on the geometry obtained from preprocedural magnetic resonance imaging and computed tomography. The electrical ostium was defined at the position with a far-field atrial signal preceding a sharp pulmonary vein (PV) signal without any isoelectric interval in between.

RESULTS: The electrically defined ostia were 8.4 ± 4.7 mm more distal in the PV compared to the anatomically defined ostia. The distances varied considerably between the four PVs and were 10.5 ± 6.5 mm, 7.4 ± 4.3 mm, 5.3 ± 4.0 mm, and 8.3 ± 3.4 mm for the left superior, left inferior, right superior, and right inferior PVs, respectively (P  =  0.009).

CONCLUSIONS: The position of the electrical and anatomical ostium differs markedly. The site of the electrical ostium is variable within the PV but always more distal in the PV compared to the site of the anatomical ostium.