Effects of tribromoethanol anesthesia on echocardiographic assessment of left ventricular function in mice

Background and Purpose: Pentobarbital and ketamine-xylazine anesthesia in m ice result in markedly decreased left ventricular fractional shortening and cardiac output. However, to the authors' knowledge, the effect of short-ac ting, alcohol-based anesthesia on these parameters is unknown. Methods: Fifteen mice (FVB/N, C57Bl/6J, A/J, n = 5 each) underwent high-res olution (15 MHz) 2-dimensional-directed M-mode echocardiography before and after undergoing 2.5% tribromoethanol anesthesia (0.01 ml/g of body weight) . Results: Tribromoethanol anesthesia resulted in significant heart rate slow ing (29%) and left ventricular enlargement (20%), and a more modest (12%) r eduction in left ventricular fractional shortening. Cardiac output was unch anged. The differences in left ventricular function between conscious and t ribromoethanol studies were similar for each of the three strains of mice. Conclusions: Tribromoethanol anesthesia induced only modest effects on M-mo de estimates of basal cardiac function and did not influence cardiac output . The effects to tribromoethanol anesthesia were similar among three common ly used mice strains.