Noninvasive mapping before surgical ablation for persistent, long-standing atrial fibrillation.

OBJECTIVE: The study objective was to study the electrophysiologic mechanism of atrial fibrillation using a noninvasive, beat-by-beat, 3-dimensional mapping technique in patients with persistent and long-standing persistent atrial fibrillation undergoing concomitant surgical ablation.

METHODS: In this pilot trial, 10 patients (6 male; mean age, 70 ± 10 years) with persistent atrial fibrillation were mapped preoperatively with a noninvasive surface system (ECVUE, CardioInsight, Medtronic Inc, Minneapolis, Minn). Eight patients were candidates for mitral valve surgery, 1 patient was a candidate for aortic valve and ascending aortic replacement, and 1 patient was a candidate for coronary bypass surgery. In 5 patients, tricuspid valve repair was also performed. The Cox-Maze III/IV was performed using combined cryoablation and bipolar radiofrequency, and the left appendage was removed in all cases. The median preprocedural duration of atrial fibrillation was 30 months, and the diameter of the left atrium was 63 mm. Atrial regions were divided according to the Bordeaux classification.

RESULTS: Preoperative mapping was successful in all patients with clear identification of the potential mechanism of atrial fibrillation. Biatrial pathology was recognized in all subjects. Rotor and macro re-entry activity were present in all patients, whereas focal activity was demonstrated in only 6 patients. Rotor activity in the right atrium was documented in all patients.

CONCLUSIONS: This is the first report on the preoperative use of the ECUVE in surgical candidates for concomitant surgical procedures. The fact that a biatrial mechanism for atrial fibrillation was detected in all patients emphasizes the importance of a Cox-Maze III/IV procedure to treat patients with valvular heart disease and nonparoxysmal atrial fibrillation. Preoperative mapping has the potential to significantly improve our understanding of the pathophysiology in atrial fibrillation and better guide the surgical ablation procedure of choice in a single patient.