Electrolyte changes in myocardial injury.

The shifts in the myocardial electrolyte metabolism during secondary or primary cardiopathies in dogs and rats, respectively, are described. Major attention is paid to the changes of Ca in the myocardial tissue. The increase in the Ca level after ligation of ramus circumflex of the left coronary artery, or after F-COL + Na2HPO4, and vitamin D2 administration, is regarded as a triggering process for more profound successive changes in the metabolism of the myocardial cell, which eventually lead to depletion of the high energy phosphate reserves. In the dogs with experimental coronary occlusion, the normalization of the myocardial ionogram, i.e., the ratio of K, Na, Ca, and Mg, was achieved by means of the mechanical heart assist, using the original design of the blood pump, where bypass and counterpulsation principles work simultaneously. The normalization of the Ca level in this case was achieved on the basis of a marked reduction of the volume work of the left ventricle, which is secured by the bypass component; on the other hand, the counterpulsation component of the combined pump secures the reduction of pressure work placed upon the left ventricle (represented by the decrease fo the end-diastolic pressure) and helps in the opening of the collaterals in the infarcted area during early diastole. Thus, the oxygen supply to the ischemic zone is improved. On the basis of our experiments with the combined blood pump, the failing heart is supported, not only hemodynamically, but also from the metabolic point of view. A similar effect is achieved by the administration of K-Mg-aspartate, and K-L- or K-DL-aspartate in dogs with experimental infarction. In primary electrolyte steroid cardiopathies characterized by necrosis, K-Mg-aspartate or K-aspartate only prevents the Ca increase in the myocardial tissue, whereas Mg-L- or Mg-DL-aspartate remains without andy effect. The necrotic changes observed after vitamin D2 administration are always accompanied by extremely high Ca levels in the myocardium. It shown in our experiments that administration of K-Mg-aspartate or Fe-dextran decreases the Ca level and reduces the necrotic and myolytic changes in the cardiac tissue. The authors recommend as an effective means in the therapy of acute heart failure the combination of mechanical heart support with the causative pharmacological therapy.