Plasma fatty acid levels in infants and adults after myocardial ischemia.

High levels of fatty acids are detrimental during reperfusion of ischemic hearts in part because of an inhibition of myocardial glucose use. We therefore measured plasma fatty acids during and after myocardial ischemia in both adult and pediatric patients. In adult patients undergoing thrombolytic therapy after an acute myocardial infarction, plasma fatty acids levels were elevated on admission to hospital (0.96 +/- 0.06 vs 0.40 +/- 0.01 mmol/L in healthy control subjects) and remained elevated throughout the initial 48 hours of hospitalization. In adult patients undergoing cardiac surgery, plasma fatty acids were markedly increased during surgery and at the time of the release of the aortic cross clamp (2.21 +/- 0.54 and 1.61 +/- 0.32 mmol/L, respectively). In children and infants (mean age 4.33 +/- 0.44 years) who had surgery to correct congenital heart defects, fatty acid levels during surgery increased to 3.27 +/- 0.26 mmol/L and remained elevated during immediate reperfusion (1.91 +/- 0.15 mmol/L) and for 24 hours after surgery (1.67 +/- 0.22 mmol/L). Because experimental studies have shown that high levels of fatty acids are detrimental to recovery of adult animal hearts, we determined the effect of high fatty acid levels on reperfusion recovery of isolated working hearts from 1-day-old rabbits perfused with 0.4 mmol/L palmitate (normal fat) or 1.2 mmol/L palmitate (high fat) and subjected to 50 minutes of global ischemia followed by aerobic reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)