Sinoatrial nodal artery injury in thoracoscopic epicardial ablation for atrial fibrillation

OBJECTIVES This study aimed to clarify the incidence of sinoatrial nodal artery (SANa) injury in thoracoscopic epicardial surgical ablation for atrial fibrillation (AF) and its impact on postoperative outcomes, which have not been previously elucidated. METHODS We enrolled 103 consecutively patients with AF who underwent thoracoscopic epicardial ablation at our institution. In these patients, we evaluated the postoperative incidence of SANa injury by using enhanced cardiac computed tomography. For patients with confirmed SANa injury, 3-day continuous electrocardiographic monitoring and exercise stress tests were performed to assess the sinus rhythm maintenance and sinus node function. RESULTS Thirteen patients (12.6%) had a confirmed SANa injury (left anterior type in 6 patients, left posterior type in 2 patients and double-branch type in 5 patients). After a median follow-up of 24 months, the patients with SANa injury were not found to be associated with lower sinus rhythm maintenance (hazard ratio 1.09, 95% confidential interval 0.36–3.31) as compared with those without SANa injury after adjustment for patient characteristics. Sinus node function was evaluated in 7 patients with SANa injury who remained in sinus rhythm after the procedure, and no sinus node dysfunction was confirmed in the 3-day electrocardiographic monitoring and exercise stress tests at a median follow-up of 12 months. CONCLUSIONS The prevalence of SANa injury in the patients who underwent thoracoscopic epicardial ablation for AF was relatively low, and the incidence of SANa injury was not associated with postoperative restoration of sinus rhythm and sinoatrial node dysfunction. More studies are required to better understand SANa injury.