Chronic Augmentation of the Parasympathetic Tone to the Atrioventricular Node: A Nonthoracotomy Neurostimulation Technique for Ventricular Rate Control During Atrial Fibrillation

Long‐Term Cardiac Neurostimulation. Introduction: The right inferior ganglionated plexus (RIGP) selectively innervates the atrioventricular node. Temporary electrical stimulation of this plexus reduces the ventricular rate during atrial fibrillation (AF). We sought to assess the feasibility of chronic parasympathetic stimulation for ventricular rate control during AF with a nonthoracotomy intracardiac neurostimulation approach. Methods and Results: In 9 mongrel dogs, the small endocardial area inside the right atrium, which overlies the RIGP, was identified by 20 Hz stimulation over a guiding catheter with integrated electrodes. Once identified, an active‐fixation lead was implanted. The lead was connected to a subcutaneous neurostimulator. An additional dual‐chamber pacemaker was implanted for AF induction by rapid atrial pacing and ventricular rate monitoring. Continuous neurostimulation was delivered for 1–2 years to decrease the ventricular rate during AF to a range of 100–140 bpm. Implantation of a neurostimulation lead was achieved within 37 ± 12 min. The latency of the negative dromotropic response after on/offset or modulation of neurostimulation was