The artery of the left atrial lateral ridge detected by multidetector computed tomography: a potential cause of atrial fibrillation recurrence after pulmonary vein catheter isolation

Abstract

Recovery of the left atrium-pulmonary vein conduction is the major cause of atrial fibrillation (AF) recurrence after catheter ablation. As previously reported by anatomical studies, the lateral ridge (LR) is located between the left atrial appendage (LAA) and the left superior pulmonary vein (LSPV). Occasionally, there is an artery following the course of the LR, which can be a cause of unablated gaps due to flow-mediated convective tissue cooling. A prospectively acquired 64-Slice Computed Tomography Angiography was performed in 60 consecutive patients (mean age 57±6 years, 43 males). We analyzed the presence and anatomical characteristics of the LR artery. Its relationship with the sinoatrial node (SAN) artery was also evaluated. The LR artery was identified in 20 cases (33%). This vessel was a branch of the circunflex artery in all cases, 8 from the proximal segment and 12 from the distal segment. The presence of this vessel was not related to the coronary dominance (91% right dominant) not the presence of atherosclerosis (58%). The minimal distance between the LR artery and the LSPV endocardium was 1.33 mm (Range: 0.6 to 5.3). Among patients in whom a LR artery was identified, the SAN artery was a branch of the LR artery in 65% (S-shaped artery), whereas it arose from another branch of the left circunflex in 15% and from the right coronary artery in 20%. In conclusion, the lateral ridge artery detected by Multi-Slice Computed Tomography has not been previously analized. It could be a common cause of AF recurrence after catheter ablation due to a flow-mediated cooling effect.