Effects of hypothermic and pharmacological protection on myocardial metabolism in temporary heart anoxia.

The authors investigated the myocardial metabolism in 11 patients in the course of the an operation (aortic valve prosthesis) under artificial circulation. In 8 patients the myocardium was protected by combined hypothermic and pharmacological cardioplegia, and in 3 patients, solely by hypothermic cardioplegia. It was found that anoxic heart arrest, regardless of the mode of myocardial protection, was accompanied by biochemical shifts in the myocardium (lactacidaemia, hyperphosphataemia, acidosis); the intensity of the shifts, however, was higher, and the durations longer, in the patients protected by hypothermic cardioplegia alone. The authors discuss the usability of the biochemical shifts in the myocardium for the prognosis of the clinical course in the early postperfusion period.