Ann Thorac Surg 1997;63:454-455
© 1997 The Society of Thoracic Surgeons
Invited Commentary
Invited Commentary
Steven F. Bolling, MD
Section of Thoracic Surgery The University of Michigan Hospitals 1500 E Medical Center Dr 2120D Taubman Center, Box , 0344 Ann Arbor, MI 48109
See also page 449.
This article by Katayama and associates highlights the frustration that many researchers in cardiac surgery have encountered. The dilemma of myocardial protection is that the protection afforded by the use of hypothermia is "too good" and overrides or attenuates the response of many beneficial additives to cardioplegia.
Many researchers using many different doses and models have investigated the use of nucleotide precursors, such as adenosine, to enhance the recovery of myocardial function after induced ischemia. Although there is controversy as to whether adenosine is acting as a substrate precursor, as a receptor signal, as a preconditioning mediator, or by some other mechanism, clearly the enhancement of adenosine in the perimyocyte milieu during and after ischemia is beneficial. Although most investigators are convinced that adenosine has a biological effect on ischemia, unfortunately, at this point in time, our standard hypothermic method of protecting the heart is "too good," and therefore it is very difficult to clinically show a significant beneficial difference with the addition of adenosine. Interestingly, with the recent interest in less profound hypothermic cardiac operations, there may be a place for myocardial preservation at a higher temperature that, although not normothermia, allows for metabolic manipulation of the myocyte and avoids the known ill effects of hypothermia. Using the precepts of myocardial metabolism and avoiding profound hypothermia may lead to better myocardial preservation and patient outcome. This may be particularly important in those high-risk patients with preexisting dysfunction, hypertrophy, or acute ischemia in whom we are not presently "too good" with our myocardial preservation.
Related Article
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Functional and Metabolic Effects of Adenosine in Cardioplegia: Role of Temperature and Concentration
- Osamu Katayama, Simon J. M. Ledingham, Mohamed Amrani, Ryszard T. Smolenski, David R. Lachno, Jay Jayakumar, and Magdi H. Yacoub
Ann. Thorac. Surg. 1997 63: 449-454.
[Abstract]
[Full Text]
