The Journal of Thoracic and Cardiovascular Surgery, Vol 75, 548-554, Copyright © 1978 by The American Association for Thoracic Surgery and The Western Thoracic Surgical Association
Cardiac hypothermia evaluated by ultrastructural studies in man
H Engedal, E Skagseth, TS Saetersdal and R Myklebust
Transmural left ventricular biopsies from 13 patients undergoing
cardiopulmonary bypass were studied. The hypertrophic myocardium was
protected by deep hypothermia (15 degrees C.) during ischemic arrest for a
maximal period of 96 minutes. Biopsies were taken at the start of bypass,
at the end of aortic cross-clamping, and after 20 minutes of reperfusion.
The structure of the mitochondria remained normal, whereas cellular
alterations in the form of widened intercalated discs, interstitial and
intracellular edema, myelin figures, and slight myofibrillar lysis were
observed in all stages. As no clear correlation between these structural
injuries and aortic cross-clamping time was seen, they are a result of
cardiac hypertrophy rather than intraoperative ischemia.