The Incidence And The Risk Factors Of Asymptomatic Atrial Fibrillation After DDD Pacemaker Implantation

Objectives:The purpose of this study was to determine the incidence and risk factors of asymptomatic atrial fibrillation in patients who received DDD pacemaker.Methods:A total of 408 patients undergoing DDD pacemaker without documented atrial fibrillation in The Shanxi cardiovascular hospital were included in this study. Each patient follow-up on 3 months,6 months and 1 year after implantation,and once a year since the second year of implantation.The details should be record including whether there is atrial high rate episode,the date,seizure frequency and duration of the episodes,whether there is atrial fibrillation happened and recorded by electrocardgram,and the episode of AHRE or atrial fibrillation is silent or have some symptoms.The primary endpoint events include the incidence of asymptomatic atrial fibrillation, the mortality and events caused by asymptomatic atrial fibrillation.Asymptomatic atrial fibrillation was defined as an atrial tachyarrhythmia with an atrial rate>250 beats per minute for more than 5 minutes or atrial fibrillation recorded by12-lead electrocardiogram,and the episodes are silent without any symptoms.While consider the atrial tachyarrhythmias occurrence at the beginning of operation may due to acute injuries of myocardium, details would be collected after 6 weeks of implantation.Using SPSS17.0 statistical software for data processing.Survival free from asymptomatic atrial fibrillation and mortality or events caused by asymptomatic atrial fibrillation was determined using the Kaplan-Meier method and differences were compared using log rank test.Cox regression analysis was used to determine the clinicalcharacteristics predictive of asymptomatic atrial fibrillation development after pacemaker implantation.The deadline of follow-up was 31 December 2015,the patients without any events happened during this period are considered as censored data.P<0.05 for two-sided comparisons was considered statistically significant.Results:The mean age of study patients cohort was( 69.40±11.46) years old and 252patients(61.76%)was male. Over a mean follow-up of(2.71±2.26)years. there were 196 patients occurred episodes of atrial rate>250 beats per minute for more than 5 minutes or atrial fibrillation recorded by 12-lead electrocardiogram,but only 105 patients(25%)ocurred without any symptoms. In a multivariable model, the incidence of asymptomatic atrial fibrillation was strongly associated with left atrial size(RR 2.414 95% CI 1.538~3.681P<0.001), hypertension(RR 1.804 95% CI 1.224~2.659 P=0.003)and congestive heart failure(RR 2.001 95% CI 1.053~3.802 P=0.034). Patients with sinus node disease were more likely to experience asymptomatic atrial fibrillation after pacemaker insertion compared with patients with atrioventricular block(P<0.001)Conclusions:1.Asymptomatic atrial fibrillation developed frequency after the implantation of dual-chamber,this phenomenon may connected with that CIED can provided a long time stored EGMs which provided the date and time of events.2.Left atrial size, hypertension and congestive heart failure was strongly associated with incidence of asymptomatic atrial fibrillation.3.Patients with sinus node disease were more likely to experience asymptomatic atrial fibrillation after pacemaker insertion compared with patients with atrioventricular block.