Influence of the Cardiac Sympathetics on Synchrony of Ventricular Contraction.

Abstract

Summary In the open chest animal, contraction of the left ventricle precedes that of the right by 5 to 35 msec. During electrical excitation of the stellate ganglion this interval decreases markedly, and in some instances, the initial elevations in intraventricular pressures occur simultaneously or nearly so. The P-R and QRS intervals generally shorten during stimulation. These observations confirm the inference that sympathetic excitation significantly alters the synchronicity of excitation and contraction of the heart chambers.