Abstract
In a former communication1 it was stated that the T wave of the electrocardiogram of the dog was a marked negative phase on the day following the ligation of branches of the left coronary arteries. This wave remained negative for a period of three to five days and then gradually became positive. The work embodied in this report was undertaken to further these observations and, if possible, inquire into the cause of the negative T wave. The anesthetic, artificial respiration and the method of exposing the heart were the same as employed in the former work. Electrocardiograms were taken daily of those dogs that survived the operation. On the second or third day following the operation they were anesthetized and the heart was again exposed. The movement of the heart was noted, especially that portion in which the blood supply had been disturbed. RESULTS OF LIGATION OF THE CORONARY ARTERIES