Impact Of Mitral Isthmus Ablation Of Persistent Atrial Fibrillation On Left Circumflex Artery

Objective The purpose of this study was to prospectively analyze the acute and sub-acute effects of mitral isthmus (MI) linear ablation on left circumflex artery (LCX) using dual source CT in patients with persistent atrial fibrillation (PersAF).Methods Fifty consecutive patients (age58±11years,36men, course of disease29months, left atrial42±6mm, ejection fraction0.62±0.09) underwent linear ablation at the mitral isthmus during an ablation procedure for PersAF. Dual source CT coronary angiography was performed before, after and a mean of38±10days after radiofrequency ablation. The reconstructive images and diameters of LCX were analyzed.Results Complete block along the MI was achieved in31(62%) patients,74%of whom required ablation in the coronary sinus (CS). The CT images of preablation showed that there were7(14%) patents with less than30%stenosis of LCX,7(14%) patents with the anatomy of LCX localized between MI and CS, and2(4%) patents without LCX at the MI sectional area. The reconstructive images of LCX after ablation and during follow-up were unchanged compared with that of preablation. The difference of LCX diameters in these three phases was not significant (2.55mm before ablation,2.32mm after ablation and2.52mm at the time of follow-up, P=0.15). In the subgroups of patients with LCX stenosis before ablation, patients undergoing CS ablation and patients with LCX localized between MI and CS, the differences of LCX diameters were not significant among preablation, postablation and one month after the ablation (P=0.45,0.09,0.36respectively).Conclusion Radiofrequency catheter ablation of mitral isthmus during persistent atrial fibrillation dose not result in short-term computed tomographic changes in circumflex artery anatomy.