Noninvasive polygraphic cardiac changes in daunorubicin-induced cardiomyopathy in rabbits.

The use of anthracycline antitumour agents (e.g., adriamycin and daunorubicin) is limited by their dose-related cardiotoxicity. The effects of the repeated i.v. administration of daunorubicin (50 mg/m2, once weekly, max. 11 weeks)) were investigated in rabbits in vivo from the point of view of the occurrence of cardiotoxicity and compared with a control group of animals. Noninvasive polygraphic records (in ketamine anaesthesia, 50 mg/kg i.m.) were used for the measurement of systolic time intervals (especially the PEP:LVET ratio) to evaluate the function of the heart. The administration of daunorubicin induced a significant, progressive increase in the PEP:LVET ratio (0.3775-0.9473) and in the PEP:LVETcorr. ratio, as well as a lengthening of the preejection period PEP and a shortening of the left ventricular ejection time LVET without significant changes in the electromechanical systole Q-2. The values in the daunorubicin group were mostly significantly different from the control group of animals. The results of polygraphic records reflect thus a presence of cardiac dysfunction on the basis of daunorubicin-induced cardiomyopathy. It is thus possible to conclude that the results obtained in the study confirm the adequacy of the rabbit model of daunorubicin-induced cardiomyopathy and the methods used in the study.