The effect of cardiac sympathetic nerve stimulation on the right ventricle in canine heart.

The change in coronary hemodynamics during right or left cardiac sympathetic nerve stimulation was studied in anesthetized open chest dogs. No difference in the increasing rate of mean coronary blood flow between right coronary artery (RCA) and left anterior descending coronary artery (LAD) was observed. However the increasing rate of right ventricular systolic pressure X heart rate (RVSP X HR) was greater than that of left ventricle (LV). With phentolamine injection, cardiac sympathetic nerve stimulation showed similar changes as the controls. Beta-stimulation by isoproterenol infusion did not cause different effects on the increasing rate of coronary blood flow between RCA and LAD. These results showed that cardiac sympathetic nerve stimulation increased the double product of the right ventricle (RV) more than that of the LV and the increase was not affected by phentolamine. Moreover, cardiac sympathetic nerve stimulation, either the right or the left, caused the greater effects on the RV compared to the LV mainly through beta-adrenoceptors, and that the response of the RV to increase in oxygen demand was possibly, in part, different from that of the LV.