Amino acid metabolism in the heart muscle in subjects with ischaemic heart disease at rest and during pacing.

In nine patients with ischaemic heart disease at rest and during pacing differences of free plasma amino acids, lactate, ammonia and uric acid between arterial blood and blood in the coronary sinus (a-cs differences) were investigated. At rest one single significant difference was found, i.e. a positive a-cs difference in aspartate. During pacing significant positive differences were recorded in aspartate, glutamate, leucine and isoleucine and significant negative a-cs differences in cystine-cysteine, glutamine and aspartic acid and in alanine. Among the correlations between a-cs differences the negative relationship between lactate and alanine and the negative correlation between cystine-cysteine and leucine, isoleucine and glutamine is significant. There is a positive relationship between the a-cs difference of alanine and glutamine and between the differences of leucine, isoleucine and glutamate. The a-cs differences of ammonia and uric acid correlate negatively.