Metabolic Protection of Ischemic Myocardium and Reduction of Infarct Size.

摘要

To evaluate cardiac cell acidosis and its treatment during ischemia,myocardial cell pH has been measured in intact anesthetized dogs by a transient indicator dilution technique. Normal myocardial cell pH averaged 6.94and changed by 58% of concomitant alterations in plasma pH following infusions of acid or alkali. Ischemia resulted in progressive decreases in cellular pH to 6.59by one hour. Infusions of Na2CO3diminished intracellular acidosis,significantly lowered left ventricular end-diastolic pressure and raised stroke volume. Ventriculograms revealed improved wall motion in the ischemic segment. Precordial mapping showed a significant reduction in the N-ST as well as the sum of ST segment elevations. Calcultion of extracellular space,tissue water and cation content revealed a reduced gain of cell Na(+) and loss of cell K(+) after alkali treatment. Enhanced delivery of glucose to ischemic myocardium improved ventricular function and reduced EKG evidence of injury. Chronic beta adrenergic blockade reduced cardiac scar.