Clinical Research Of Low Atrial Septum Pacing For Prevention Of New-on Atrial Fibrillation In Patients With Sick Sinus Syndrome

Objective:To explore the efficacy of making the low atrial septum pace by adopting active fixation electrode. Evaluate the efficacy for prevention of new-on atrial fibrillation to analyze the incidence of the atrial fibrillation and the comparison between P wave dispersion and left atrial volume index(LAVI) after low atrial septum and right atrial appendage pacing.Methods:We selected 66 patients with sick sinus syndrome who needed the pacemakers for DDD from 2013 february to 2014 April. All patients were randomly divided into two groups:36 patients in the RAA pacing group and 30 patients in the LAS pacing group. Follow-up was 12 months. The operating time and X-ray exposure time of the two groups were compared. Chosen from the 12-lead ECG of the body surface, the objects measured above were all clear and their baseline was stable. Measured P wave duration(P wave maximum duration and P wave minimum duration) of postoperative pacing ECG, calculated P wave dispersion, and compared P wave dispersion between the two groups. Defined P wave beginning as the starting point of the earliest baseline leaving and P wave end as the ending point of the lastest baseline returning. The objects of the ECG were measured by the same person. During the follow-up (1 month,3 months,6 months,12months), P wave dispersion and left atrial volume index were detected and the incidence of atrial fibrillation (AF) was compared between the two groups.Results:(1) Preoperative clinical data were not different between the septum and the appendage groups. (2)The operation time and X-ray exposure time in LAS group were significantly longer than those in RAA group (50.1±4.8 min vs 42.9±5.5min, P<0.01; 8.1±1.7 min vs 5.3±1.5min, P<0.01).(3) the incidence of AF was lower in LAS group(3.3%) compared with the RAA group(19.4%). (4) P wave dispersion in RAA group was significantly higher than that in the LAS group 1 month,3 months,6 months,12months after operation(40.78±10.72ms vs 24.10±10.87ms; 42.13±10.97ms vs 23.86±10.76ms; 42.53±11.07ms vs 25.23±10.92ms; 43.91±11.34ms vs 25.30±11.41ms. p<0.01). (5) LAVI was not different between the septum and the appendage groups 1 month after operation(P=0.19). LAVI was significantly different between the septum and the appendage group 3 months,6 months,12 months after operation(24.01±4.88ml/m2 vs 21.67±4.13ml/m2; 24.07±5.03ml/m2 vs 21.47±4.36ml/m2; 24.90±5.04ml/m2 vs 21.22±4.37ml/m2,3 months,6 months,12 months, after operation,in order, P=0.04; P=0.03; P< 0.01), in RAA group LAVI was larger.Conclusion:In LAS group compared with the RAA group the incidence of AF may be lower and P wave dispersion and LAVI are significantly lower after atrial pacing in sick sinus syndrome. LAS group is superior to RAA group in preventing progression to new-on atrial fibrillation. LAS pacing is superior to RAA pacing though the fixation to the LAS is more complicated.