Adriamycin cardiomyopathy: enhanced cardiac damage in rabbits with combined drug and cardiac irradiation.

Rabbits received either (a) no treatment; (b) a single radiation dose; (c) protracted low-dose Adriamycin; (d) combined cardiac irradiation and low-dose Adriamycin; or (e) protracted high-dose Adriamycin. More severe myocardial lesions (similar to those in high-dose Adriamycin groups) developed in rabbits receiving combined treatment. Pericardial effusions and fibrosis were more common in the combined treatment group.