Longitudinal assessment of left and right ventricular systolic function in dogs undergoing chemotherapy with doxorubicin

Cardiotoxicity is a recognized complication of chemotherapy with doxorubicin and is classically associated with left ventricular dysfunction; however, evidence from human cardio-oncology suggests that global cardiac function, including the right ventricle, may also be affected, and that advanced echocardiographic techniques such as global longitudinal strain (GLS) and tissue motion annular displacement (TMAD) may detect subtle myocardial dysfunction earlier than conventional indices. This prospective longitudinal study evaluated 25 dogs with cancer undergoing doxorubicin chemotherapy, administered alone or in combination with other drugs, using conventional echocardiography and speckle tracking before treatment and at 7, 21, 60, 120 and 180 days after the first dose. Twelve dogs completed all evaluations. No significant changes were observed over time in left ventricular volumes, fractional shortening, ejection fraction, global circumferential strain or GLS. However, reductions in MAPSEi lateral (P = 0.002), MAPSEi septal (P = 0.0293) and global TMAD% (P=0.046) were observed at 180 days compared with baseline, along with decreased E' wave velocity and a negative correlation between cumulative doxorubicin dose and the E:A ratio, suggesting a dose-dependent effect on diastolic function. In the right ventricle, progressive reductions in TAPSEi (P<0.001), RV S'n wave (P=0.036), FAC (P=0.04), RV GLS (P=0.002) and RV TMAD (P=0.019) were observed over time. These findings indicate subclinical reductions in indices of systolic function of both ventricles, highlighting the sensitivity of MAPSE, TAPSE and TMAD for early detection of myocardial alterations. Parte superior do formulário Parte inferior do formulário Parte superior do formulário Parte inferior do formulário.