Electrocardiographic and Vectorcardiographic Changes Produced by Electrical Stimulation of the Cardiac Nerves

Abstract
The electrocardiographic and vectorcardiographic changes produced by electrical stimulation of the cardiac nerves were investigated. Stimulation of the right stellate ganglion produced superior displacement of the spatial T loop with change in its direction of inscription from clockwise to counterclockwise in the right sagittal plane. With stimulation of the left stellate ganglion, the T loop increased its magnitude interiorly with or without preceding transient superior displacement. The superiorly displaced T loop was inscribed clockwise in the right sagittal plane, which was different from the counterclockwise inscription of the T loop observed with stimulation of the right stellate ganglion. From these results, there appears to exist some difference in the innervation of the myocardium by right and left cardiac sympathetic nerves. Stimulation of the cervical vagus nerves produced minimal changes in the electrocardiogram and vectorcardiogram, and no definite results were obtained from the examination of the vector loop.