Steroids and Cardioplegia

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