Selective parasympathectomy of the heart

Attempts to devise a chronic animal model with parasympathetic cardiac denervation have been complicated by early mortality due to pulmonary and esophagogastric dysfunction. By use of surgical techniques confined to the intrapericardial left atrium and immediately adjacent vena cava, selective cardiac parasympathectomy was performed on dogs. Verification of denervation was performed at the time of surgery by electrical stimulation of the cervical and thoracic vagi and stellate ganglia while recording blood pressure, ECG, and atrial and ventricular contractile force. Results demonstrate complete efferent parasympathetic denervation and abolition of the Bezold-Jurish reflex. Tachycardia at approximately 140/min was noted in all animals immediately and for several weeks postoperatively. No extracardiac complications were noted in any of the animals subjected to this procedure. Right heart catheterization of the conscious sedated dog revealed no evidence of right heart failure. Evidence of parasympathetic efferent reinnervation (sinus arrhythmia) was seen in some animals. This preparation should prove useful in studies of parasympathetic control of the heart, coronary vessels, and cardiovascular reflexes.