Electrocardiogram in the Normal Rat and Its Alteration with Experimental Coronary Occlusion

A reliable and reprodueible method of recording rat electrocardiograms is described, including the use of precordial electrodes This system was utilized in studying 44 nor mal animals and in recording the electrical abnormalities associated with the ligation of the left coronary artery in 10 rats. The char acteristics of the normal electrocardiogram of the rat arc described. Following apical and anterior infarction, Q waves in associatioii with transitory R-wavc augmentation ap peared, with prolongation of the Q-T interval, electrical axis deviation, and inversion of the T wave. No abnormal conduction patterns were noted. The pathological lesions are described, and attention is called to the absence of mural intraventrienlar thrombosis despite transmnral infarction.