Percutaneous ablation for atrial fibrillation: the role of cross-sectional imaging

Percutaneous ablation is a well-established technique for treating cardiac arrhythmia by removing or isolating tissue at the site of the abnormal impulse formation. Various forms of energy for ablation procedures may be delivered via a catheter with fluoroscopic guidance. The procedures most commonly performed are radiofrequency ablation and cryotherapy. Atrial fibrillation, the most frequently occurring supraventricular tachyarrhythmia, may be initiated by ectopic beats that originate in the ostia of the pulmonary veins. The clinical efficacy of isolation (or focal ablation) of the pulmonary veins for treatment of atrial fibrillation has been well demonstrated. Pre- and postprocedural examinations with computed tomography (CT) or magnetic resonance (MR) imaging are frequently performed to depict the anatomy and to obtain baseline measurements of the pulmonary veins to enable early detection of complications from ablation. Venous stenosis or thrombosis and pulmonary hypertension may occur after radio-frequency ablation. Familiarity with the appearance of normal anatomic variants at CT and MR imaging and with the normal range of pulmonary vein diameters is essential for preoperative management and early detection of procedure-related complications.