Time-dependent Cervical Vagus Nerve Stimulation and Frequency-dependent Right Atrial Pacing Mediated Inducibility of Atrial Fibrillation

Abstract

OBJECTIVE: This study aimed to investigate the effects of right cervical vagus trunk simulation (RVTS) and/or right atrial pacing (RAP) on the induction of atrial fibrillation (AF). METHODS: Twenty-four healthy adult dogs were randomly divided into four groups: RAP groups comprising RAP500 (RAP with 500 beats/min) and RAP1000 (RAP with 1000 beats/min) and RVTS groups comprising RVTS and RAP500+RVTS. All dogs underwent 12-h intermittent RAP and/or RVTS once every 2 h. The AF induction rate, AF duration, atrial effective refractory period (ERP), and dispersion of ERP (dERP) were compared after every 2 h of RAP or/and RVTS. RESULTS: All groups had successful AF induction. The RAP1000 group had the highest AF induction rate and the longest AF duration. The RAP1000 group also had a shortened ERP in comparison to the other groups as well as the maximum dERP. Compared to the RAP500 group, RAP500+RVTS had an increased capacity to induce AF as measured by the AF induction rates, AF duration, ERP, and dERP. CONCLUSION: Increased tension in the vagus nerve and the intrinsic cardiac autonomic nervous system plays an important role in AF induction through different potential mechanisms. Interventions involving the vagus nerve and/or intrinsic cardiac autonomic nervous system can be a future potential therapy for AF.