Objectives: This study sought to determine the distance between the anterior wall of the left atrial appendage (LAA) ostium to the left main coronary artery (LMCA) and the left circumflex artery (LCx) in patients undergoing left atrial appendage electrical isolation (LAAEI).
Background: LAAEI improves outcomes in nonparoxysmal atrial fibrillation ablation. There is a potential risk of damaging the LMCA and the LCx during LAAEI.
Methods: Patients undergoing LAAEI during the period between January 1, 2017 and October 31, 2018, were included in this study. Patients underwent cardiac computed tomography prior to ablation. The position of the LAA was analyzed. The closest distances between the LMCA, its bifurcation, LCx, and the anterior wall of the LAA ostium were measured. Additionally, imaging integration was performed to localize these vessels and catheter ablation was performed at least 5 mm away.
Results: A total of 74 patients (mean age: 68 ± 9.5 years; male 54%) who underwent LAAEI were included. The mean distance from the anterior wall of the LAA ostium to the LMCA was 7.88 ± 2.8 mm, to the LMCA bifurcation was 9.24 ± 4.40 mm, and to the LCx was 10.03 ± 4.56 mm. The LCx artery was found along the LAA ostium in 98% of the cases, whereas the LMCA was found in only 48.6%. No coronary damage or vasospasm was observed after performing LAAEI.
Conclusions: A detailed imaging integration with cardiac computed tomography, electroanatomic mapping, and CARTOSOUND reconstructions to accurately define the anatomical relationship between the LMCA and LCx and the anterior edge of the LAA ostium should be performed prior to delivering radiofrequency energy during LAAEI. When the distance on cardiac computed tomography between the LAA ostium and left coronary arteries is >10 mm, intraprocedural localization of these vessels may be not necessary.
Keywords: left atrial appendage; left circumflex coronary artery; long-standing persistent atrial fibrillation; persistent atrial fibrillation; radiofrequency ablation.
Copyright © 2020. Published by Elsevier Inc.