Right vagal nerve stimulation for coronary anastomosis without cardiopulmonary bypass: investigation in dogs.
BACKGROUND
The purpose of this study is to assess the potential of right vagal nerve stimulation for reducing the heart rate during coronary anastomosis without cardiopulmonary bypass.


METHODS
Through the fourth left intercostal space, left internal thoracic artery grafts were sutured to the left anterior descending artery with the heart beating. In Group I (n=7), two dogs underwent right cervical vagal stimulation alone and five dogs underwent right cervical vagal stimulation during intravenous infusion of diltiazem or verapamil. In Group II (n=3), one dog underwent right thoracic vagal stimulation alone and two dogs underwent right thoracic vagal stimulation during intravenous infusion of diltiazem or verapamil. The thoracic vagal nerve was isolated endoscopically. The electrocardiogram and aortic pressure were monitored during interventions.


RESULTS
In Group I, cervical vagal stimulation reduced the heart rate from 190 to 45 and 180 to 42 b/min. During intravenous infusion of diltiazem or verapamil, cervical vagal stimulation caused ventricular arrest. In Group II, thoracic vagal stimulation decreased the heart rate from 205 to 70 b/min, and stimulation during intravenous infusion of diltiazem caused ventricular arrest.


CONCLUSIONS
Right vagal stimulation during intravenous infusion of diltiazem or verapamil has potential value as a technique for reducing the heart rate during coronary anastomosis without cardiopulmonary bypass.
Hayashi
I
I
Department of Thoracic and Cardiovascular Surgery, Juntedo University 2-1-1, Hongou Bunkyo-ku, Tokyo, Japan, 113-8431.
Yamamoto
T
T
Hosoda
Y
Y
D000714:Anastomosis, Surgical; D000818:Animals; D002317:Cardiovascular Agents / Q000494:pharmacology; D003331:Coronary Vessels / Q000601:surgery*; D004110:Diltiazem / Q000494:pharmacology; D004285:Dogs; D004558:Electric Stimulation; D004562:Electrocardiography; D006339:Heart Rate / Q000187:drug effects; D007432:Intraoperative Period; D019060:Minimally Invasive Surgical Procedures; D013900:Thoracic Nerves / Q000502:physiology; D014630:Vagus Nerve / Q000502:physiology*; D014700:Verapamil / Q000494:pharmacology
D002317:Cardiovascular Agents; D014700:Verapamil; D004110:Diltiazem