Role of right middle pulmonary vein in patients with paroxysmal atrial fibrillation

Introduction: Elimination of the ectopic foci from pulmonary veins (PVs) has proved to be a curative therapy for focal atrial fibrillation (AF). However, information about the importance of the right middle PV (RMPV) in initiation of AF and radiofrequency ablation of AF is limited. Method and Results: Forty-three patients (34 men and 9 women; age 65 ± 12 years) with drug-refractory paroxysmal AF underwent electrophysiologic study and catheter ablation for treatment of AF. Three-dimensional magnetic resonance angiography (MRA) of the PVs and left atrium (LA) was performed to determine the anatomic patterns of RMPV. Diameter of PV ostium was measured at the junction of the LA and each PV. MRA findings showed the following: (1) 36 (84%) of 43 patients had a discrete RMPV; (2) there are three drainage patterns of RMPV, including joining the proximal part (80% of paroxysmal AF patients. Ectopy from RMPV can initiate AF, and radiofrequency ablation of RMPV foci is feasible and safe.