Abstract
Daunomycin (DM)-and Adriamycin (AM)-induced cardiomyopathy was investigated clinically and pathologically.
Ten of the 110 cases of acute leukemia treated with DM and AM (9.1%) developed cardiomyopathy and 4 cases died of it. DM at a dose of more than 1,600mg as a total and 2.0mg/kg/month (AM more than 800mg as a total and 1.0mg/kg/month) induced cardiomyopathy in six of the 12 cases (50%) with fatal outcome in four, but at a lesser dose in both respects did not. Six patients with cardiomyopathy including all fatal cases were under 20 years of age.
It is suggested that the tolerable therapeutic dosage of DM should be under 1,600mg total and 2.0mg/kg/month and equivalent amount of AM and that the longer survival may bring about the more increased incidence of cardiomyopathy. Moreover, it seems to suggest that the cardiomyopathy occurred with considerably higher frequency in young group than elderly one.
Pathological findings of cardiomyopathy were as follows: while no abnormalities were found in weight, size, form and coronary arteries of the heart, the subendocardial myocardium showed yellowish discoloration. Microscopically, there were vacuolization and anisocytosis of myocardial cells, polymorphic nuclei, homogeneous and edematous swelling and replacement by collagenous fibers in myocardium, especially in subendocardial myocardium. The higher dosage and the longer survival seemed to emphasize these pathologic changes. The atrioventricular conducting system was found to have similar changes.
