Evaluation of cardiac effects of the medetomidine-vatinoxan and methadone combination in healthy dogs: radiographic and echocardiographic assessment.

To evaluate the cardiac changes in healthy dogs sedated with medetomidine-vatinoxan and methadone, underdoing echocardiographic and radiographic evaluation. a prospective, clinical study A group of 18 dogs Dogs received intramuscularly methadone (0.1 mg kg -1 ) with medetomidine-vatinoxan (0.015–0.3 mg kg -1 in dogs < 20 kg or 0.01–0.2 mg kg -1 in dogs > 20 kg). Cardiovascular variables and sedation were recorded at baseline (T0), 5, 10 and 15 minutes post injection. Echocardiography and thoracic radiographs for vertebral heart score (VHS) were assessed before (T0), and 15 (T15) and 20 (T20) minutes later, respectively. Left ventricular (LV) end-systolic diameter and volume, LV fractional shortening, ejection fraction, aortic and pulmonary blood flow were measured amongst other variables. Data are shown as the mean ± standard deviation p < 0.05. Sedation was achieved by T5. Heart rate decreased from T0. The blood pressure increased at T5 and thereafter was < baseline. After sedation, VHS increased (from 10.6 ± 0.9 to 11.0 ± 1.1) and the LV end-systolic diameter (from 2.5 ± 0.5 cm to 2.8 ± 0.6 cm) and volume (from 23.6 ± 8.2 mL m -2 to 31.5 ± 11.1 mL mq -2 ) increased (overall p < .001). A decrease of LV fractional shortening (from 34.1 ± 7.2% to 27.0 ± 7.0%; p < .001), ejection fraction (from 63.3 ± 7.8% to 53.8 ± 10.1%; p < 0.001), aortic flow (from 144.9 ± 37.6 cm second -1 to 121.1 ± 36.9 cm second -1 ; p < .001), pulmonary flow (from 93.2 ± 19.8 cm second -1 to 76.9 ± 17.8 cm second -1 ; p < .001) were observed. Medetomidine-vatinoxan and methadone induced significant radiographic and echocardiographic changes, which were of limited clinical concern in this population of dogs. However, they should be considered when this drug combination is used.