title: Abnormal right atrial electrograms predict the transition to chronic atrial fibrillation in paced patients with sick sinus syndrome.
abstract: Although pacing therapy for sick sinus syndrome (SSS) is established, the risk of developing chronic atrial fibrillation (CAF) makes pacing therapy infeasible in some patients. We evaluated whether electrophysiological characteristics of atrial muscle can serve as predictors of the transition to CAF after pacemaker implantation in patients with SSS. Eighty-nine patients with SSS underwent electrophysiological study before pacing therapy. Catheter mapping of 12 right atrial sites was performed during sinus rhythm during electrophysiological. An abnormal atrial electrogram was defined as having a duration of 100 ms or longer, or eight or more fragmented deflections, or both. Right atrial extrastimulation was also performed for atrial vulnerability. After electrophysiological study, all patients underwent pacemaker implantation and were followed up. During the follow-up period of 85 +/- 50 months, development of CAF was observed in 12 patients (group A). The remaining 77 patients remained in sinus rhythm (group B). There were significantly more abnormal atrial electrograms in group A than group B (2.7 +/- 2.3 vs 0.8 +/- 1.2; P < 0.001). The distribution of abnormal atrial electrograms was also greater in group A; patients in group A had more abnormal atrial electrograms than patients in group B in both the high and middle right atrium (P < 0.005 and P < 0.01, respectively). Kaplan-Meier analysis showed that almost 50% of the paced patients with abnormal atrial electrograms (n = 42) developed CAF (P < 0.005). Our data suggest that the existence of abnormal atrial electrograms is predictive of the transition to CAF in paced patients with SSS.
authors.affiliation: Department of Cardiovascular Medicine, Course of Medical and Dental Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Sakamoto, Nagasaki, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Kojiro
authors.initials: K
authors.lastname: Nakao
authors.forename: Shinji
authors.initials: S
authors.lastname: Seto
authors.forename: Riyako
authors.initials: R
authors.lastname: Shibata
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Doi
authors.forename: Satoki
authors.initials: S
authors.lastname: Fukae
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Matsuo
authors.forename: Norihiro
authors.initials: N
authors.lastname: Komiya
authors.forename: Katsusuke
authors.initials: K
authors.lastname: Yano
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000503:physiopathology*; D002304:Cardiac Pacing, Artificial; D002908:Chronic Disease; D018450:Disease Progression; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012804:Sick Sinus Syndrome / Q000503:physiopathology* / Q000628:therapy