Effect of medetomidine on left ventricular outflow tract velocity in cats: A Doppler echocardiography study

The purpose of the present study was to evaluate effects of medetomidine on left ventricular outflow tract (LVOT) velocity in domestic short-haired cats. Eighteen healthy adult male domestic short-haired cats were used for this study. All animals were client-owned. Echocardiography machine with 7.50 MHz transducer was used. Specific veterinary two-dimensional and pulse-waved echocardiogram images in apical five chamber right parasternal view were obtained and blood velocity in LVOT was calculated. After baseline echocardiographic recordings, 0.04 mg kg^-1 of medetomidine was intramuscularly administered to each animal and LVOT velocity was calculated after 15 (T15), 50 (T30) and 80 (T80) min following drug administration. The LVOT velocity values (mean SEM) of cats in baseline were 1.06 0.04 m sec^-1. There were significant differences between baseline and T15 and T30 regarding mean LVOT values. Age and weight had no significant effect on LVOT velocity values. The LVOT velocity values of T15, T50 and T80 were 0.77 0.04, 0.80 0.02 and 0.960.03 m sec^-1, respectively. Our findings revealed significant decrease in mean LVOT velocity up to 50 min following medetomidine administration. The present study determined normal LVOT velocity range for a small population of cats before and after intra-muscular medetomidine administration.