P-226 Factors of atrial fibrillation recurrence in right atrial appendage paced patients with sick sinus syndrome

The present study investigated the factors of atria1 fibrillation (AF) recurrence in right atria1 appendage paced patients with sick sinus syndrome. Methods: Fifty-six patients (aged 68&10 years; 19 men, 38 women) with sick sinus syndrome who received right appendage pacing were divided into 2 groups: 23 patients without AF (I+II; Rubenstein I or II) and 34 patients with AF (III; Rubenstein III). AF group was subdivided into 2 groups; 20 patients (IIIb) with a paced P wave in both leads II and V1 >130 msec, and the other 14 patients (IIIb). The clinical and electrocardiographic data and the actuarial curve of the paroxysmal AF free interval were compared among each group, and the factors of AF recurrence were analyzed through a logistic regression model. Results: During the follow-up of 40&21 months, AF recurrence was significantly higher in group IIti than in group IIIa, I+11 (17120 vs. 5114 vs. 1123 pP wave in leads II and VI was signiiicantly greater in group III than in group I+11 (119&20 vs. 108&21 msec, p=O.O417, 106&16 vs. 95&21 msec, p=O.O258, respectively). No significant differences were observed in comparison of the intrinsic P width between group IIIa and IIIb in leads II and Vl (122&19 vs. 117&19 msec, 105&19 vs. 107&14 msec, respectively). On the other hand, the duration of paced P wave in group IIIa was similar in group I+11 (122&9 vs. 127&18 msec, 121&9 vs. 127&17 msec, respectively) although the duration of P wave in group IIti was prolonged largely after RAA pacing. Multivariate analyses revealed that the independent risk factors of AF recurrence were pre-pacing AF and prolonged P duration after right appendage pacing. Conclusion: Alternative-site pacing will be needed to shorten paced P wave duration and prevent AF in sick sinus syndrome complicated with AF and the aggravation of atria1 conduction delay induced by right appendage pacing.