Original communication
Further observations on the ischemia-injury pattern produced in the dog by temporary occlusion of a coronary artery. Incomplete T diversion patterns, theophylline T reversion, and theophylline conversion of the negative T pattern

https://doi.org/10.1016/S0002-8703(44)90921-XGet rights and content

Abstract

  • 1.

    1. The ischemia-injury pattern, although produced by sudden, complete, brief occlusion of a coronary artery, is in no way dependent upon the presence of myocardial infarction. However, the pattern demonstrates the early electrocardiographic changes which may be encountered before and during the early development of myocardial infarction. Contrary to general opinion, the first electrocardiographic change is a primary T-wave change ascribed to acute local ventricular ischemia.

  • 2.

    2. The diversion stages of the pattern may be arbitrarily interrupted by terminating the occlusion, whereupon reversion of the pattern promptly occurs.

  • 3.

    3. The negative T diversion induced by dissection of the coronary artery can frequently be reverted by an intravenous administration of 0.12 Gm. of theophylline with ethylene diamine.

  • 4.

    4. After the theophylline T reversion, the ischemia-injury pattern, which was formerly of the negative T variety, is converted in all essential particulars to a pattern of the positive T variety.

  • 5.

    5. Evidence is presented which indicates that the ischemia-injury pattern owes its characteristics to acute local changes in that region of the ventricular wall which is subjacent to the exploring electrode, a region ordinarily irrigated by the occluded artery.

  • 6.

    6. An explanation is offered for the occurrence of two typical patterns rather than one.

  • 7.

    7. Certain electrocardiographic changes are observed after the administration of theophylline with ethylene diamine, and are ascribed to a decrease in the intensity and (or) extent of local ischemia and injury, a decrease produced by improvement of the collateral circulation.

  • 8.

    8. The clinical significance of the ischemia-injury pattern and of its behavior under varied circumstances is briefly discussed.

Cited by (6)

Presented at the meeting of the Southern Section of the Society for Experimental Biology and Medicine, June 25, 1943.

View full text