Ann Thorac Surg 1995;59:802
© 1995 The Society of Thoracic Surgeons
Discussion
DISCUSSION
See also page 795.
DR WILLARD M. DAGGETT, JR (Boston, MA): I very much enjoyed hearing this paper, which supports other studies in terms of the results obtained. However, I do have some problems with the design of the experiment, which appears to compare apples and oranges. By combining different temperatures (warm versus cold) with different delivery techniques (retrograde versus antegrade) you make impossible the interpretation of the data in terms of which is or are the discriminating factors responsible for the results obtained. I would hope that you would repeat these studies comparing one delivery method versus another at the same temperature or a single delivery method at different temperatures to help us further understand the determining factors for the methods of myocardial protection you describe.
DR VAN CAMP: This study was designed to compare two types of common clinically used techniques of cardioplegia: warm continuous retrograde and cold intermittent antegrade cardioplegia. These are standard techniques that are used and have been well described in the literature. We found that in the setting of global ischemia, there was inferior protection by the warm technique. Further studies of what caused this result need to be performed. We believe it is because of inadequate oxygen delivery by the retrograde route to effectively end the ischemic period.
DR ROBERT E. HIEB (Las Vegas, NV): How did you decide on the rate of your retrograde cardioplegia, because in clinical practice most of us are using about twice that amount as far as the rate of delivery of the cardioplegia? We believe for many hearts 180 to 200 mL/min is necessary to provide optimal protection.
DR VAN CAMP: That rate of delivery of the retrograde cardioplegia was derived from the initial report by the group out of Toronto in which they described their techniques. Their range of delivery was used and then scaled down to an animal model.
Related Article
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Functional Recovery After Ischemia: Warm Versus Cold Cardioplegia
- Joseph R. Van Camp, Louis A. Brunsting, III, Keith F. Childs, and Steven F. Bolling
Ann. Thorac. Surg. 1995 59: 795-802.
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