Magnetic Resonance Angiography of Pulmonary Veins: Implications for Catheter Ablation of Atrial Fibrillation

INTRODUCTION: Catheter ablation of atrial fibrillation (AF) requires exact anatomical information about pulmonary venous (PV) ostia. In this study, anatomy of pulmonary veins (PVs) was assessed using three-dimensional (3D) reconstructions of magnetic resonance angiography (MRA). METHODS AND RESULTS: Contrast-enhanced MRA of the PVs was performed in 40 patients (mean age 53 +/- 9 years) with paroxysmal (30 patients) or persistent (10 patients) AF, scheduled for circumferential ablation around PV ostia. PV ostial anatomy and diameters were evaluated from multiplanar reconstructions and compared with 3D reconstructions. Thirty (75%) patients presented with a common left-sided antrum (21 short and 9 long trunk), while additional PVs were found on right side in 23%. PV ostia were oblong in shape (mean diameters 17.0 +/- 4.3 vs 10.5 +/- 2.5 mm by two-dimensional (2D) measurements, and 20.8 +/- 7.6 mm vs 12.9 +/- 3.3 mm by 3D reconstruction, in long and short axis, respectively). There was a correlation between measurements obtained from 2D and 3D images, although 3D imaging provided slightly larger diameters. CONCLUSIONS: MRA with 3D reconstructions is an important technique for preprocedural assessment of PVs that allows full understanding of their anatomy and size. This information may be important for selection of appropriate tools.