The Cox-Maze III Procedure Success Rate: Comparison by Electrocardiogram, 24-Hour Holter Monitoring and Long-Term Monitoring

Background. The detection of atrial arrhythmia recurrence is more accurate when using long-term (5 days to 3 weeks) continuous monitoring devices. In this study, we focus on the comparison of the recurrence of atrial arrhythmias in patients after the Cox-Maze III procedure obtained by three modalities: electrocardiography (ECG), 24-hour Holter monitoring, and long-term monitoring (LTM). Methods. Patients with follow-up longer than 6 months who reported sinus rhythm while not taking antiarrhythmic drugs were eligible. Atrial arrhythmias longer than 30 s were considered a recurrence. The ECG, 24-hour Holter monitoring, and LTM (5 days) reports were ascertained and compared at the same time. Results. Patients (n = 291) underwent the full Cox-Maze III procedure, with 194 eligible for the study and 76 agreeing to participate. The average time to monitoring after surgery was 9.8 (+/- 7.7) months. The ECGs determined 96% of patients in sinus rhythm, Holter monitoring determined 91% in sinus rhythm, and LTM indicated 84% in sinus rhythm. Comparing ECG results and LTM results revealed that 9 patients (12%) had a significant rhythm change. Holter monitoring did not capture all the patients having events lasting longer than 1 hour. No additional information was captured by the use of LTM in patients with paroxysmal atrial fibrillation. Conclusions. This study reconfirmed that ECG overestimated the success rate after the Cox-Maze III operation by 12% compared with LTM. These changes may carry clinical significance when determining the success of the Cox-Maze III procedure and determining the medical management, including antiarrhythmic and anticoagulation therapy, of the patients who were found to have significant events. (Ann Thorac Surg 2009;88:101-5) (C) 2009 by The Society of Thoracic Surgeons