Effects of chemotherapy treatment with doxorubicin on right ventricular function in dogs.

Left ventricular dysfunction in dogs after the administration of doxorubicin (DOX) has been extensively examined. However, the effects of DOX on right ventricular (RV) function remain unknown. Therefore, the present study investigated whether the chemotherapy treatment with DOX decreases RV function. Twelve dogs (five with multicentric lymphoma, four with hemangiosarcoma, two with thyroid cancer, and one with lung adenocarcinoma) that received at least two doses of DOX were prospectively enrolled. Echocardiography and the measurement of troponin I were performed prior to each administration of DOX and approximately one month after the last administration. Right ventricular function was assessed by the RV fractional area change and RV Tei index. Two (n=4), three (n=3), four (n=3), and five (n=2) doses of DOX were administered. While no significant differences were observed in the RV fractional area change, the RV Tei index was significantly impaired after two doses of DOX. Troponin I level significantly increased after four doses. Cumulative doses of DOX correlated with the RV Tei index (r=0.77, P<0.001). The present results demonstrated that the chemotherapy treatment with DOX decreased RV function in a dose-dependent manner in dogs.