Independent protection provided by red blood cells during cardioplegia.
Isolated, blood-perfused dog hearts were subjected to 2 hours of arrest at 27 degrees C and perfused at 15-minute intervals with either a potassium crystalloid cardioplegic solution (KCC) or an identical solution to which washed red blood cells were added (KrbcC). After reperfusion, hearts protected with KCC were easily defibrillated and systolic pressure returned to 62% of prearrest values 90 minutes after reperfusion. In hearts protected with KrbcC, systolic pressures recovered to 103% of prearrest values 15 minutes after reperfusion. Metabolic variables recovered more quickly in hearts perfused with KrbcC. Adenosine triphosphate did not decline with arrest in either group. Creatine phosphate values decreased with KCC and increased with KrbcC. The pH of the myocardial effluent fell to 6.48 during arrest with KCC and to 7.19 with KrbcC (p less than 0.001). Carbon dioxide tension increased with KCC, but decreased with KrbcC (p less than 0.001). Thus, marked improvement in recovery after 2 hours of arrest is seen with KrbcC. Protection beyond that provided by KCC appears  solely due to the washed red cells, and may be the result of the buffering action of the red cell improved oxygen delivery.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D003326:Coronary Circulation; D004285:Dogs; D004912:Erythrocytes; D006324:Heart Arrest, Induced; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007552:Isotonic Solutions; D009206:Myocardium / Q000378:metabolism*; D010101:Oxygen Consumption; D010725:Phosphocreatine / Q000378:metabolism; D011188:Potassium; D017680:Potassium Compounds
D007552:Isotonic Solutions; D017680:Potassium Compounds; C018369:potassium cardioplegic solution; D010725:Phosphocreatine; D000255:Adenosine Triphosphate; D011188:Potassium