Purpose: The Cox maze IV (CMIV) procedure is being used increasingly frequently for surgical ablation of atrial fibrillation (AF). This study aimed to identify the risk factors of the need for postoperative pacemaker implantation (PMI) after CMIV.
Methods: Preoperative, intraoperative, and postoperative data were retrospectively collected from 67 consecutive patients who underwent CMIV at our institution; 7 (10.4%) required PMI (as a treatment of brady AF or sick sinus syndrome).
Results: Patients who needed PMI tended to have lower preoperative heart rates than those who did not on a 12-lead electrocardiogram (ECG; 68.7 ± 11.6 vs. 79.1 ± 18.5 bpm, p = 0.07) and a 24-h ECG (94,772 ± 9800 vs. 109,854 ± 19,078 beats/day, p = 0.03). A multivariate analysis identified a low amplitude of the fibrillatory wave on preoperative ECG as a risk factor of PMI necessity after CMIV [odds ratio = 14.7; 95% confidence interval (CI) 1.9-324.7; p = 0.007] and internal use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (ACEIs/ARBs) as a negative risk factor (odds ratio = 0.16; 95% CI 0.02-0.99; p = 0.049).
Conclusions: A low amplitude of the fibrillatory wave was identified as a risk factor of PMI necessity, whereas the internal use of ACEIs/ARBs diminished the need for PMI. These factors should be considered before CMIV is performed.
Keywords: Amplitude of fibrillatory wave; Angiotensin-converting enzyme inhibitor; Atrial fibrillation; Maze procedure; Pacemaker implantation.