The Maze Procedure and Postoperative Pacemakers

Background: There is concern that the right atrial lesions of the maze procedure lead to more permanent pacemakers postoperatively and that they provide little therapeutic advantage over left atrial lesions alone. Methods: A discussion of the pertinent anatomy related to atrial fibrillation and the performance of the maze procedure, the potential ways that the specialized conduction system could theoretically be damaged by the procedure, non–procedure-related causes for increased postoperative pacemaker requirements, and the basis for the efficacy of the right atrial lesions of the maze procedure are presented. Several factors that can lead to a dysfunctional sinoatrial node preoperatively in patients with atrial fibrillation are also discussed. Results: The reasons new permanent pacemakers are required after a maze procedure include the high success rates of the surgery with subsequent unmasking of preoperative sick sinus syndrome, excessive extracardiac dissection that damages the autonomic nerve input to the heart, premature pacemaker implantation for a temporary junctional rhythm immediately postoperatively, surgical error, and patient selection. Conclusions: There are numerous reasons why patients need new pacemakers after a maze procedure, but the right atrial lesions of the procedure rarely, if ever, are the cause.