Metabolically controlled reperfusion in acute myocardial infarction: should the polarizing solution be given...

Area of Science:

• Cardiovascular Research
• Myocardial Infarction Treatment
• Ischemia-Reperfusion Injury

Background:

• Metabolic support aids recovery in injured heart tissue post-myocardial infarction.
• Clinical use of systemic "polarizing solutions" suggests efficacy.

Purpose of the Study:

• To assess the feasibility of subselective delivery of metabolic substrates before reperfusion in a canine ischemia/reperfusion model.
• To evaluate the impact of specific metabolic solutions on infarct size and arrhythmias.

Main Methods:

• Thirty-five dogs underwent 90-minute coronary artery ligation.
• Randomized groups received direct reperfusion, glucose-insulin-potassium (GIK), or GIK plus propionyl-L-carnitine (PLC).
• Endpoints included arrhythmias, mortality, infarct size, and histology.

Main Results:

• Propionyl-L-carnitine (PLC) eliminated ventricular fibrillation associated with higher dextrose concentrations.
• Group III (GIK + PLC) showed significantly larger irreversibly injured myocardial areas (85.9%) compared to Groups I and II (16.9%).
• Mortality during early reperfusion was 32.1% (9/28 dogs).

Conclusions:

• Subselective infusion of metabolic solutions during acute myocardial infarction is technically feasible.
• Low dextrose (<5%) perfusate is essential to prevent osmotic endothelial damage.
• PLC demonstrated protective effects against reperfusion injury in this model.