Independence of Ventricular Arhythmia from Insufflations to Coronary Flow in Rabbits

Abstract

In a previous paper 1 it was demonstrated that a left ventricular arhythmia produced from insufflations of benzol in tracheotomized animals was contingent on impulses which descend the median part of the lateral columns of the spinal cord and reach the heart by way of the stellate ganglia. The purpose of this report is to record some observations which suggest that this arhythmia is not dependent on the nutrient supply of the heart. This arhythmia is normally preceded by a moderate rise in carotid pressure, a change which Markwalder and Starling, 2 Anrep and Segall, 3 Hochrein, Keller and Mauke 4 would place first, as a means for producing an increased coronary supply. The arhythmia never appeared when blood pressure was low (40 mm. and below). Double vagotomy in no way delayed the onset or shortened the interval of this arhythmia, except possibly for a short interval immediately after sectioning. Porter, 5 Mass, 6 Wiggers, 7 Anrep and Segall, 3 Greene 8 and others demonstrated that the constrictor fibers for the coronaries run in the vagi and Anrep and Segall 3 have demonstrated that double vagotomy causes a considerable increase in the coronary flow.

If a change in the nutrient supply to the nerve-intact heart is the cause of the arhythmia from insufflations, it should be due to an increase in the coronary flow rather than to a decrease. To demonstrate the effect on the pulse of a brief interval of anemia of the left ventricle, the left interventricular artery and the left ventricular vein were ligated close to the atrium in a number of animals for several minutes, and in a few animals the right interventricular artery was also ligated.