This study evaluates the capacity of regional substrate-enriched blood cardioplegia reperfusion (without bypass) to salvage cardiac muscle subjected to 40 minutes of regional ischemia. Results are compared with those obtained by normal blood reperfusion at either systemic or reduced perfusion pressure (i.e., simulating acute angioplasty or streptokinase thrombolysis). All studies were carried out in beating, working hearts when the conditions of reperfusion were not controlled. The results show that regional cardioplegic reperfusion without cardiopulmonary bypass reduces the incidence of reperfusion ventricular fibrillation (15% versus 55%, p < 0.05), increases recovery of subendocardial creatine phosphate (35.3 versus 14.0 μmol/gm, p < 0.05) and adenosine triphosphate (6.0 versus 3.1 μmol/gm, p < 0.05), reduces histochemical damage evaluated by triphenyltetrazolium chloride (0% versus 43% transmural nonstaining, p < 0.05), and improves myocardial contractile reserve capacity (91% versus 41%, p < 0.05). Normal blood reperfusion restored immediate systolic shortening in only 3 of 18 hearts (17%), and regional cardioplegic reperfusion without bypass produced early recovery of regional systolic shortening in only 10 of 16 hearts (63%, p > 0.05). Thus the value of controlling reperfusate composition without simultaneous control of reperfusion conditions is limited.
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Cardiology and Cardiovascular Medicine