BIOCHEMICAL-CHARACTERIZATION OF MYOCARDIAL DAMAGE IN CHRONIC CHAGAS-DISEASE

Background: In the early asymptomatic stages of cardiomyopathy in chro nic Chagas' disease, septal endomyocardial biopsies disclose multiple evidence of evolving myocardial damage. Detection of signs of an activ e myocardiopathic process may allow a better understanding of the evol ution of this and other related dilated cardiomyopathies and provide a means for evaluation of the result of future therapeutic schemes. Hyp othesis: This study was designed to explore whether cellular damage ca used by Chagas' disease is reflected by changes of certain serum elect rolytes, enzymes, and glycoproteins associated with myocardial metabol ism, especially in the coronary sinus into which the blood just metabo lized by the heart is drained. Methods: The study included 47 patients (35 men and 12 women, average age 40 years) with positive complement fixation reaction and hemagglutination test for Chagas' disease. The s tudy protocol included medical records, electrocardiographic (EGG) rec ordings, routine laboratory analysis, chest x-rays, noninvasive cardia c examinations, and cardiac catheterization. Results: In this study, w e determined the concentration or activity of 9 electrolytes, 5 glycop rotein fractions, and 12 enzymes related to cardiac metabolism in bloo d from the coronary sinus, the superior vena cava, the pulmonary and f emoral arteries, and found early release of inorganic phosphorus (p<0. 01) and isocitrate dehydrogenase (p<0.01) from the heart and increased activity of serum alkaline phosphatase and aldolase (p<0.05). Discrim inant analysis suggested that the combination of the clinical picture, electrocardiographic findings, and peripheral activity of serum aldol ase might be useful for the recognition of 86% of patients with Chagas ' disease without segmental myocardial damage, 80% of those with early segmental abnormalities, and all patients with advanced myocardial da mage or congestive heart failure. Conclusion: These results would make the application of more invasive techniques, such as left cineventric ulography for detection of early myocardial compromise, unnecessary.