摘出ラット心表面における興奮伝播図

抄録

In order to describe activation sequences on the left ventricular epicaraium(LVEp) of the isolated rat heart, epicardial isochronal maps were obtained by using. Wistar rats Five males, 25-30 weeks of age, which were coofirmed to have noo conduction disturbances by analyting electrocardiograms and vectorcardiograms recorded prior to removing their hearts, were used. Each isolated heart was perfused by the Laogendorff method and was mounted on the cardiac muscle chamber filled with 35 ml normal oxygenated Tyrode's solution at 37°C. It was stimulated by a bipolar electrode with rectangular pulse wave of 4 msec and 2 Hz, the electrode having been placed in the right atrial septum after the sinus node had been crushed. In mappig procedure, a fixed reference bipolar electrode was applied on the surface of LVEp, and a roviog electrode was run by the conventional microelectrode method. The results and conclusion are as follows : 1) The earliest breakthrough site on the LVEp was found in the anterior paraseptal region near the cardiac base. 2) The latest activation site was found at the center of the free wall of LVEp, i. e., The posterobasal region.