Pulmonary vein dilation in patients with atrial fibrillation: Detection by magnetic resonance imaging

Introduction: The positive relationship between left atrial (LA) size and atrial fibrillation (AF) is well recognized; however, there is little information on the association of pulmonary vein (PV) diameter and AF, The purpose of this study was to investigate by magnetic resonance angiography the change of PV and LA size in patients with no history of AF, patients with paroxysmal AF (PAF), and patients with chronic AF (CAF). Methods and Results: The study included 47 patients. Group I included 15 patients with normal sinus rhythm and no history of documented AF, Group II included 24 patients with drug-refractory PAF who underwent electrophysiologic study and radiofrequency ablation of PV foci, Group III included 8 patients with CAF who were converted to sinus rhythm by external electrical cardioversion, Age and concomitant heart diseases were similar among the three groups. We measured the diameter of each PV at its junction with the LA in addition to LA dimensions by gadolinium-enhanced magnetic resonance angiography with three-dimensional reconstruction. Significant dilation of both superior PVs (P < 0.01) and transverse diameter of LA (P < 0.01) was seen in the three groups. There were no significant changes of both inferior PVs, corrected PV (PV/LA) diameter, or longitudinal diameter of LA among the three groups. Only 28% patients showed arrhythmogenic foci from the largest PV, Conclusion: Significant dilation of both superior PVs with simultaneous LA enlargement was demonstrated in PAF and CAF patients. Although PV size cannot predict AF firing, the anatomic and geometric differences may participate in perpetuation of AF.