Ventricular fractional shortening in 108 dogs with malignant lymphoma undergoing chemotherapy with a cyclic combination protocol including doxorubicin.

OBJECTIVE The aim of this study was to evaluate whether changes in the left ventricular fractional shortening (LVFS) can be detected in dogs with malignant lymphoma undergoing a cyclic combination chemotherapy protocol including doxorubicin. HYPOTHESIS Left ventricular fractional shortening as a stand-alone measurement will not show a significant change during the cyclic combination protocol. MATERIAL AND METHODS In this retrospective study, the records of dogs with malignant lymphoma treated between April 2001 and October 2010 were reviewed. Inclusion criteria comprised: a diagnosis of malignant lymphoma, a cyclic combination chemotherapy (including L-asparaginase, vincristine, cyclophosphamide, doxorubicin and prednisolone), and an echocardiographic examination by an experienced examiner before treatment and after each doxorubicin administration. RESULTS One hundred and eight dogs were included and a total of 446 LVFS measurements had been performed. Patients were divided into four groups according to the number of doxorubicin administrations. Median LVFS did not change significantly during the cyclic combination protocol in all groups. All median LVFS values remained above the lower reference value of 25%. CONCLUSION AND CLINICAL RELEVANCE The measurement of LVFS did not show a significant change during the cyclic combination protocol treatment including doxorubicin in this population of dogs. Therefore either this cyclic combination protocol does not cause a systolic dysfunction or LVFS is not sensitive enough to detect early changes. Newer methods that are more sensitive then LVFS might be necessary to detect such changes.