Rod-like intramitochondrial inclusions after hypothermic chemical cardioplegia during cardiac operations.

Rod-like intramitochondrial inclusions in the myocardial cells were observed after hypothermic chemical cardioplegia in three out of 20 patients who underwent coronary bypass operations. They were not seen in another group of 20 patients who underwent an aortic valve replacement operation in whom only topical cooling was used for myocardial protection. The occurrence of rod-like intramitochondrial inclusions could not be correlated with other signs of ischemic myocardial injury. X-ray microanalysis did not reveal any inorganic substance in the intramitochondrial inclusions. Therefore, we believe that their occurrence was not related to the calcium paradox phenomenon, a feared complication of cardiac operations.