Preservation of high energy phosphates in hypertrophied human myocardium.

Hypertrophied hearts are extremely vulnerable to ischemia. In 61 patients with aortic valve disease undergoing surgery we investigated the quality of myocardial protection obtained with three different methods of crystalloid cardioplegia. To exclude the influence of temperature differences the regional myocardial temperatures were continuously measured and adjusted to the same level in all patients. Before and after ischemia and after 10 minutes reperfusion myocardial biopsies were taken and the high energy phosphates and lactic acid determined. In one group St. Thomas cardioplegia was used, in another Bretschneider cardioplegia and in the third the Hamburg method. There were no significant differences between the three groups at the end of ischemia and after 10 minutes reperfusion. After 10 minutes reperfusion the metabolic alterations caused by ischemia were in part reversible. From our results we conclude that each of the cardioplegias used is able to protect a hypertrophied heart adequately against ischemia during cardiac arrest.