Dilatation as a marker of pulmonary veins initiating atrial fibrillation

Background: The pulmonary veins (PVs) have been shown to trigger paroxysmal atrial fibrillation. The relationship of anatomical dimensions versus arrhythmogenicity has not been assessed. Methods: The diameters of four PVs were measured by selective PV angiography before ablation in 39 consecutive patients (23 male, mean age 46 years) with only one (25 patients) or two (14 patients) arrhythmogenic PVs (ArPVs). After ablation of ArPVs, no patient had recurrence of atrial fibrillation from the remaining PVs. Comparisons were performed variously between ArPV and non-ArPV, and within and across both groups. Results: ArPVs were distributed as follows; left superior PV: 40%, left inferior PV: 28%, right superior PV: 26%, and right inferior PV: 6%. Statistical comparisons showed that (1) Triggers of atrial fibrillation were located in the largest PV in 72% of patients, (2) For each PV, the mean diameter of ArPV was significantly larger than that of non-ArPV (p < 0.05), (3) No significant difference was observed in the diameter of the four different ArPVs (range 16.2 +/- 1.3 to 17.2 +/- 4.4). Conclusions: In patients with atrial fibrillation initiated from one or two ArPVs, the diameters of ArPVs were significantly larger than those of non-ArPVs irrespective of the specific PV concerned, which might imply a possible role of PV dilatation in the arrhythmogenesis.