Myocardial preservation by Bretschneider's solution (BR solution, Group I) with an intracellular like electrolyte and histidine buffer action was compared with EC-Bi solution (Group II) which has an extracellular like electrolyte and bicarbonate buffer action in the mongrel dogs. The PH and PCO2 of the effluent from the coronary sinus were maintained during myocardial ischemia for 3 hr but the lactate rose gradually in group I. The oxygen and lactate up-take ratio of the myocardium after re-perfusion was satisfactory and LV max dp/dt was also maintained at a high level in group I. Morphologically, myelin figure and mitochondrial deformation were more found in group II on electron microscopy.
A donor heart preserved for 3 hr in cold BR solution was transplanted in the left thoracic cavity in four mongrel dogs by the technique of the heterotopic cardiac transplantation. Resuscitation of cardiac pulsation was smooth and maintenance of the systemic circulation after transplantation was possible in every case. From these findings, it might be concluded that myocardial preservation using cold BR solution was useful for cardiac transplantation
