HUMAN MYOCARDIAL ATP CONTENT AND IN-VIVO CONTRACTILE FUNCTION

The study was designed to characterize the relationship between the me tabolite content of human cardiac muscle and in vivo cardiac function. ATP, total adenine nucleotides, and NAD were quantified in human myoc ardial biopsies using high performance liquid chromatography. Right ve ntricular endomyocardial biopsies were obtained from 43 patients with dilated cardiomyopathy, 6 with restrictive cardiomyopathy, 10 with nor mal systolic and diastolic function, and from 24 cold preserved human donor hearts. Transmural samples of failing right and left ventricular free walls were obtained during cardiac transplantation surgery in 8 patients. ATP, total adenine nucleotides, and NAD were similar in the cold-preserved donor hearts and in right ventricular endomyocardial bi opsies from the 10 individuals with normal systolic and diastolic func tion. In contrast, these values were significantly depressed in tissue samples from patients with dilated or restrictive cardiomyopathy. The re was a significant correlation between ATP and pulmonary capillary w edge pressures but not ejection fractions. Declines in the sizes of my ocardial ATP, adenine nucleotide, and pyridine nucleotide pools in the human myocardium are associated primarily with diastolic but not syst olic dysfunction.