Right versus left atrial pacing in patients with sick sinus syndrome and paroxysmal atrial fibrillation (Riverleft study): study protocol for randomized controlled trial

Abstract

BackgroundThe incidence of sick sinus syndrome will increase due to population ageing. Consequently, this will result in an increase in the number of pacemaker implantations. The atrial lead is usually implanted in the right atrial appendage, but this position may be ineffective for prevention of atrial fibrillation. It has been suggested that pacing distally in the coronary sinus might be more successful in preventing atrial fibrillation episodes. The aim of this trial is to study the efficacy of distal coronary sinus versus right atrial appendage pacing in preventing atrial fibrillation episodes in patients with sick sinus syndrome.Methods/DesignThis study is designed as a multicenter, randomized controlled trial. Patients with sick sinus syndrome and at least one atrial fibrillation episode of 30 seconds or more in the six months before recruitment will be eligible for participation in this study.All participants will be randomized between pacing distally in the coronary sinus and right atrial appendage. Randomization is stratified for all participating centers. Conventional dual-chamber pacemakers with advanced home monitoring functionality will be implanted. The ventricular lead will be implanted in the right ventricular apex. The first three months of the 36-month follow-up period are considered as run-in time. During the pre-randomization visit and follow-up, an interview, electrocardiogram and pacemaker assessment will be performed, prescribed antiarrhythmic medication will be reviewed and patients will be asked to complete an SF-36 questionnaire. An echocardiographic examination will be conducted in the pre-randomization phase and at the end of each follow-up year. Home monitoring will be used to send daily reports in case of atrial fibrillation episodes.DiscussionThis randomized controlled trial is the first in which home monitoring will be used to compare atrial fibrillation recurrences between pacing in the distal coronary sinus or right atrial appendage. Home monitoring gives the opportunity to accurately detect atrial fibrillation episodes and to study characteristics of atrial fibrillation episodes. Should distal coronary sinus pacing significantly diminish atrial fibrillation recurrences, this study will redefine the preferential location of an atrial lead for preventive pacing.Trial registrationCurrent Controlled Trials ISRCTN65911661, registered on 8 July 2013.

Effects of Ivabradine on Cardiac Electrophysiology in Dogs with Age-Related Atrial Fibrillation

“…Our previous studies have also shown that If was closely related to AF, and the mRNA and protein levels of HCN channels increased significantly in the atrial muscles of patients with AF [ 20 ]. The decrease in the sinoatrial node function, increase in the activities of ectopic pacemakers including atrium and pulmonary veins, and increase of local automaticity with age could increase the risk of ectopic arrhythmia [ 21 ]. Li et al [ 22 ] showed that the density of If was significantly higher in the cardiac myocytes from pulmonary vein sleeves of aged dogs with AF than in the ones with sinus rate.…”

Review of the epidemiology, pathogenesis and prevention of atrial fibrillation after pacemaker implantation

“…However, studies have shown that RAA pacing changes the normal atrial pacing conduction sequence, increases the intra-atrial conduction time and makes the left and right atria asynchronous, which contributes to mitral valve regurgitation, increases the LA pressure and eventually leads to atrial structural and mechanical remodeling and an increased incidence of AF. 95,96 Therefore, scholars have proposed reducing burden of AF after pacemaker implantation by changing the atrial pacing site (Fig. 2).…”