[Myocardial electrolytes in "cardioplegic" myocardosis (author's transl)]

Changes of the mineral concentrations of the heart muscle can point at disturbances of myocardial metabolism. Disturbances of heart muscle with functional loss and without coronary or inflammatory heart disease are called myocardosis, especially cardioplegic myocardosis after open-heart surgery with extracorporal bypass. 30 dogs were examined in three groups varying the method of induced cardiac arrest: 1. ischemic cardiac arrest by clamping the ascending aorta, 2. functional cardiac arrest by electrically induced fibrillation and 3. ischemic cardiac arrest and in addition injection of a Mg-aspartate-procain-solution. Sodium, potassium, magnesium, calcium, copper and zinc were analyzed by atomic absorption spectrophotometry. Specimens from the left and right ventricular wall were examined before and after extracorporal circulation. After a recovery period for one hour the dogs were killed and specimens from the right and left ventricular wall and from the basis and apex of the interventricular septum were taken and reduced to ashes with mineral acids. In all animals changes of the mineral content were most marked after the recovery period. In all forms of cardiac arrest mineral metabolism showed monotone reactions: water content increased, potassium and magnesium decreased. Variations of mineral concentrations were more expressed in the right ventricular wall than in the left. Animals with cardiac arrest by electrically induced fibrillation indicated the smallest deviations from the basic values. The comparison of the values of dogs with sufficient circulation at the end of the experiments and those dogs with medicamentally or mechanically supported circulation at this time showed a more increased water content and simultaneously a decrease of all cations in the group with supported circulation. The decrease of the osmolality of the cations seems to be the metabolic answer to the increased cardioplegic damage of heart muscle.