Effect of the carotid sinus nerve stimulation on nutritive myocardial blood flow in regional cardiac ischaemia.

The authors have studied the local blood flow regulation of the heart under the influence of the stimulation of the carotid sinus nerve in segmental myocardial ischaemia. The experiments were carried out on 38 dogs. By ligating the mid-portion of the left anterior descending coronary artery, a small artificial infarction has been produced. Circulatory examinations were made after 24 hours following the coronary ligation. In 18 dogs the circulatory investigations were done during the electrical stimulation of the carotid sinus nerve while 20 dogs were used as control. The local nutritive blood flow of the heart was measured by the administration of 86 rubidium in the intact zone, in the ischaemia (necrotic) zone and at the border zone of the heart. According to the experimental data, under the influence of the carotid sinus nerve stimulation the blood flow of the intact zone does not change considerably while the necrotic and border zones increases to a great extent. Reflex redistribution of the myocardial blood flow probably plays a decisive role in the antianginal effect of carotid sinus nerve stimulation.