[Cardiotoxicity of mitoxantrone]

Cardiotoxicity induced by mitoxantrone was studied in 50 closely followed patients receiving chemotherapy with mitoxantrone. Serial electrocardiograms were recorded. The electrocardiographic parameters (heart rate, P-Q interval, QRS interval, QRS voltage, and QTc interval) were analyzed. The patients who received mitoxantrone showed no significant changes in these parameters. Furthermore, in order to investigate the details of acute cardiotoxicity of mitoxantrone and adriamycin, Holter ECGs were recorded and some of the electrocardiographic parameters were analyzed. The basic rhythm was sinus rhythm in all cases except for only one case which developed intermittent atrial fibrillation after adriamycin therapy. No effect on the specialized conduction system was observed on either group. Supraventricular premature beat showed no significant changes, but ventricular premature beat showed a tendency to increase and the mode of appearance of the ventricular extrasystole was very dangerous in the adriamycin-administered group. Developed ST-T changes were also seen in the adriamycin group. In conclusion, mitoxantrone seemed to have less cardiotoxicity in comparison with that of adriamycin.