R-wave voltage in the right precordial leads in anthracycline cardiomyopathy: experimental animal model

Electrocardiographic abnormality, similar to that observed in cancer patients during chemotherapy with the anthracycline antibiotics daunomycin and adriamycin, was produced in rabbits. They were chronically treated with adriamycin, and before each administration of the drug an electrocardiogram was recorded. They were subdivided into two categories with respect to the R-wave voltage in lead V1, on the same basis as our previous investigation in humans. In group A, there was a dose-response relationship, and they ultimately showed a QS pattern in the right precordial leads with or without ST-T changes in the left precordial leads. In group B, the electrocardiograms did not show a low R-wave in lead V1, but ST-T changes in the left precordial leads. The similarity of these electrocardiographic changes to those produced by myocardial infarction that we observed in humans suggests that more severe injury to the myocardium at the anterior septum and anterior left ventricular wall may be important in the pathogenesis of anthracycline cardiomyopathy.