Dichloroacetate stimulates carbohydrate metabolism but does not improve systolic function in ischemic pig heart.

Increased carbohydrate utilization may protect the heart during ischemia and reperfusion. Dichloroacetate (DCA) stimulates pyruvate dehydrogenase, which is the rate-limiting step in oxidation of lactate and pyruvate. The purpose of this study was to determine if the myocardial metabolic changes induced by intracoronary DCA during myocardial ischemia were accompanied by improvement in systolic function.

Coronary blood flow autoregulation and flow heterogeneity in the stunned heart.

We used an anesthetized swine model of regionally "stunned" myocardium to determine the effect of stunning on coronary autoregulation and blood flow heterogeneity. In 18 domestic swine, stunning was accomplished by reducing blood flow to the left anterior descending coronary artery (LAD) by approximately 75% of baseline for 15 min and restoring it to normal for 1 hour. We quantified coronary autoregulation using both the slope of coronary pressure-flow curves and an autoregulation index.

Coronary pressure-flow regulation in the stunned myocardium.

In this study, we used a swine model to study coronary autoregulation in the stunned myocardium. In 18 domestic swine, the left anterior descending coronary artery was cannulated and flow to this artery controlled via an extracorporeal perfusion circuit. Stunning was induced by reducing pump flow to approximately 25% of the baseline value for 15 minutes followed by 1 hour of reperfusion.

Effects of high arterial oxygen tension on function, blood flow distribution, and metabolism in ischemic myocardium.

Background: Although oxygen inhalation therapy has long been used in the treatment of acute myocardial ischemia, experimental evidence that increased arterial PO2 has any beneficial effect in the absence of hypoxemia is equivocal. In this study, we used a swine model of subendocardial myocardial ischemia to determine the effects of arterial hyperoxia on regional myocardial contractile function (sonomicrometry), myocardial blood flow distribution (microspheres), and regional myocardial glycolytic metabolism (carbon isotope-labeled substrates).

Methods And Results: In 10 domestic swine, the left anterior descending coronary artery was cannulated and flow to this artery was strictly controlled via a roller pump in the perfusion circuit.