title: Electrophysiological evaluation of the sinus node and the cardiac conduction system following the maze procedure for atrial fibrillation.
abstract: Transient sinus node dysfunction has been demonstrated by noninvasive methods following the maze procedure for atrial fibrillation (AF). However, extensive data from invasive electrophysiological studies have not been previously reported. Thirty-seven patients, mean age 54 +/- 10 years, underwent the maze (III) procedure. Electrophysiological studies with recordings of SNRT, CSNRT, AVN-ERP, point of Wenckebach block, AH, PA, and HV interval, were performed preoperatively and 6 and 15 months postoperatively. Induction of atrial flutter/AF was attempted postoperatively. Based on electrophysiological study evaluation, the maze (III) procedure did not cause permanent damage to the sinus node in any patient with a documented normal sinus node function preoperatively (CSNRT max 541 +/- 210 vs 587 +/- 437 ms, P = 0.26). Postoperative AV node function was normal in all patients with a documented normal AV node function before surgery. One patient had an iatrogenic third degree AV block. There was no difference in PA or HV interval after surgery. Sustained atrial tachyarrhythmias could be induced in 5 patients, of whom 4 developed permanent AF/atrial flutter late after surgery. At late follow-up, (mean 45 months), 27 (73%) patients were in sinus rhythm, 5 (13%) patients had permanent pacing, and 5 patients had recurrent AF requiring His bundle ablation (n = 2) or medical treatment (n = 3). Based on electrophysiological studies, the maze (III) procedure does not cause permanent damage to the sinus or AV nodes or to the right atrial and His-Purkinje conduction systems. Electrophysiological study evaluation may predict the need for postoperative pacemaker. Induction attempts of atrial arrhythmias may predict future recurrences and guide therapeutic efforts.
authors.affiliation: Department of Cardiothoracic Surgery and Anesthesiology, Karolinska Institutet at Huddinge University Hospital, Stockholm, Sweden. anders.albage@hs.se
authors.forename: Anders
authors.initials: A
authors.lastname: Albåge
authors.forename: Dan
authors.initials: D
authors.lastname: Lindblom
authors.forename: Per
authors.initials: P
authors.lastname: Insulander
authors.forename: Göran
authors.initials: G
authors.lastname: Kennebäck
mesh_terms: D000328:Adult; D000368:Aged; D020517:Atrial Appendage / Q000601:surgery; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D016280:Atrial Function, Right / Q000502:physiology; D001283:Atrioventricular Node / Q000503:physiopathology; D002036:Bundle of His / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial; D003452:Cryosurgery / Q000379:methods; D004594:Electrophysiology; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000601:surgery; D006329:Heart Conduction System / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011690:Purkinje Fibers / Q000503:physiopathology; D012032:Refractory Period, Electrophysiological; D012189:Retrospective Studies; D012849:Sinoatrial Node / Q000503:physiopathology* / Q000601:surgery; D013997:Time Factors