Summary
The influence of glucocorticoid supplementation to cardioplegic Solutions is still
open to debate. The isolated working rat heart model was used to test the efficacy
of glucocorticoid (methylprednisolone sodium succinate (MPSS)) supplementation to
2 clinical cardioplegic Solutions. Hearts were subjected to either 80 minutes or 120
minutes of hypothermic (18.5 °C) global ischemia after single-dose administration
(4 °C) of one of the cardioplegic Solutions A (“Hamburg” Solution) or B (simple potassium-based
Solution). Each cardioplegic Solution was infused containing either MPSS in the clinically
used concentration (250 mg/l or 500 mg/l for Solution A and B, respectively) or without
MPSS. The recovery of aortic flow, coronary flow, peak aortic pressure and heart rate
was compared with preischemic control values. Creatine kinase (CK) release was measured
in the early reperfusion period and the myocardial content of ATP was measured at
30 minutes of reperfusion.
Solution B provided only a moderate protection against ischemic damage. Inclusion
of MPSS 500 mg/l slightly improved the recovery of physiological indices, reduced
CK leakage and increased myocardial ATP. Solution A provided a more effective protection
against ischemia. The addition of MPSS in this Situation did not affect the Overall
postischemic recovery. We suggest that the addition of MPSS may improve the protective
properties of a cardioplegic Solution when the ischemic injury is rather severe.
Key words
Cardioplegia - Glucocorticoid supplementation - Myocardial ischemia - Isolated rat
hearts
