Differential effect of right and left vagal stimulation on right and left circumflex coronary arteries

In anasthetised, closed-chest dogs in complete heart block that were paced at a ventricular rate of 100 beats/min, vagal stimulation increased right coronary (RC) flow by 46% and conductance by 59%, but these increases were less than those measured in the left circumflex coronary (LCC) flow (66%) and conductance (80%). Both the right and left vagus nerves affected RC and LCC flow, the left vagus having the greater effect. The response to vagal stimulation is not limited at higher ventricular rates.