Glucose-insulin-potassium preserves systolic and diastolic function in ischemia and reperfusion in pigs

Clinical and experimental studies have suggested benefit of treatment with intravenous glucose-insulin-potassium(GIK) in acute myocardial infarction. However, patients hospitalized with acute coronary syndromes often experien ce recurrent myocardial ischemia without infarction that may cause progress ive left ventricular (LV) dysfunction. This study tested the hypothesis tha t anticipatory treatment with GIK attenuates both systolic and diastolic LV dysfunction resulting from ischemia and reperfusion without infarction in vivo. Open-chest, anesthetized pigs underwent 90 min of moderate regional i schemia (mean subendocardial blood flow 0.3 ml.g(-1).min(-1)) and 90 min re perfusion. Eight pigs were treated with GIK (300 g/l glucose, 50 U/l insuli n, and 80 meg/l KCl; infused at 2 ml.kg(-1).h(-1)) beginning 30 min before ischemia and continuing through reperfusion. Eight untreated pigs comprised the control group. Regional LV wall area was measured with orthogonal pair s of sonomicrometry crystals. GIK significantly increased myocardial glucos e uptake and lactate release during ischemia. After reperfusion, indexes of regional systolic function (external work and fractional systolic wall are a reduction), regional diastolic function (maximum rate of diastolic wall a rea expansion), and global LV function (LV positive and negative maximum ra te of change in pressure with respect to time) recovered to a significantly greater extent in GIK-treated pigs than in control pigs (all P < 0.05). Th e findings suggest that the clinical utility of GIK may extend beyond treat ment of acute myocardial infarction to anticipatory metabolic protection of myocardium in patients at risk for recurrent episodes of ischemia.