Effects of anesthesia on diastolic function in mice assessed by echocardiography

Transthoracic echocardiography is the predominant diagnostic tool to evaluate systolic and diastolic cardiac function noninvasively in mice. It is known that systolic function is substantially influenced by anesthetic agents used for sedation during echocardiography. However, the effect on diastolic function has not been investigated yet. The following study was conducted to evaluate the influence of different agents on diastolic left ventricular function in mice.

The effect of ketamine/xylazine (K/X), ketamine/midazolam (K/M), and tribromoethanol (TBE, Avertin) on diastolic function was measured 5, 15, and 25 minutes after the onset of anesthesia. Ratio of peak early-to-late myocardial diastolic velocities (Ea/Aa; determined by tissue Doppler imaging; TDI), ratio of peak transmitral early (E)- and late-diastolic velocity (E/A), deceleration time (DT), and isovolumic relaxation time (IVRT) correlated significantly with heart rate (HR). Overall, increasing HR contributed to a decrease of E/A-, Ea/Aa ratio, IVRT, and DT, whereas agents characterized by the strongest variation of HR (K/M and TBE) were associated with the greatest effect on diastolic function.

Left ventricular diastolic function in mice, determined by echocardiography, is dependent on anesthetic agent and timing of measurements after onset of anesthesia.