Sudden death of experimental animals following intrapericardial injections of tincture of iodine.

Abstract

During the course of some experiments on rabbits, it was noted that injection of tincture of iodine (U. S. P.) into the pericardial sac was followed by some unidentified disturbance of cardiac mechanism which resulted in the death of the animals within a few minutes. The same series of events followed in each of the five animals employed. Six dogs were then studied. Under ether intratracheal anesthesia, the chest was opened and from 1.5 to 2 cc. of tincture of iodine injected, with much the same results as with the rabbits. As soon as the first few drops of the solution touched the epicardium there was an obvious visible effect on the heart muscle which continued until the death of the animal within five to ten minutes. Examining the heart grossly after death, it was found that the iodine had diffused over the entire epicardium but there was no visible evidence of staining of the heart muscle beneath the serous covering. In order to determine, if possible, the sequence of events following the injection of the irritant, the next two experiments were carried out in the Department of Physiology with the animals attached to the electrocardiograph. The first animal alone succumbed to the first dose of iodine. The second animal failed to show the usual prompt response and death did not occur until three injections of iodine had been given. We have no positive explanation to give of the phenomena observed. The rapidity of the effect of the injection would make it improbable that there was any systemic disturbance; rather it would point to a purely local action of the alcohol on the heart muscle or the electrical mechanism of the organ.