Chronic atrioventricular nodal vagal stimulation : First evidence for long-term ventricular rate control in canine atrial fibrillation model

• Published in: Circulation (New York, N.Y.) N.Y.), 2005-11, Vol.112 (19), p.2904-2911
• Main Authors: YOUHUA ZHANG, YAMADA, Hirotsugu, BIBEVSKI, Steve, SHAOWEI ZHUANG, MOWREY, Kent A, WALLICK, Don W, OH, Seil, MAZGALEV, Todor N
• Format: Article
• Language: English
• Subjects: Animals; Atrial Fibrillation - therapy; Atrioventricular Node - innervation; Biological and medical sciences; Blood and lymphatic vessels; Blood. Blood coagulation. Reticuloendothelial system; Cardiology. Vascular system; Cardiovascular system; Disease Models, Animal; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Dogs; Electric Stimulation Therapy - methods; Medical sciences; Pharmacology. Drug treatments; Telemetry; Vagus Nerve - physiology; Vascular wall; Ventricular Function
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/CIRCULATIONAHA.105.568832

We have previously demonstrated that selective atrioventricular nodal (AVN) vagal stimulation (AVN-VS) can be used to control ventricular rate during atrial fibrillation (AF) in acute experiments. However, it is not known whether this approach could provide a long-term treatment in conscious animals. Thus, this study reports the first observations on the long-term efficacy and safety of this novel approach to control ventricular rate during AF in chronically instrumented dogs. In 18 dogs, custom-made bipolar patch electrodes were sutured to the epicardial AVN fat pad for delivery of selective AVN-VS by a subcutaneously implanted nerve stimulator (pulse width 100 micros or 1 ms, frequency 20 or 160 Hz, amplitude 6 to 10 V). Fast-rate right atrial pacing (600 bpm) was used to induce and maintain AF. ECG, blood pressure, and body temperature were monitored telemetrically. One week after the induction of AF, AVN-VS was delivered and maintained for at least 5 weeks. It was found that AVN-VS had a consistent effect on ventricular rate slowing (on average 45+/-13 bpm) over the entire period of observation. Echocardiography showed improvement of cardiac indices with ventricular rate slowing. AVN-VS was well tolerated by the animals, causing no signs of distress or discomfort. Beneficial long-term ventricular rate slowing during AF can be achieved by implantation of a nerve stimulator attached to the epicardial AVN fat pad. This novel concept is an attractive alternative to other methods of rate control and may be applicable in a selected group of patients.