RESUMO
Objective To compare echocardiographic parameters of left ventricular function in mice under anaesthesia with those in conscious condition.Methods Forty mice were randomized to anesthetic group and nonanesthetic group,all mice were examined in conscious state at baseline,then anesthetic group had intraperitoneal injection of ketamine and xylazine,the non-anesthetic group received intraperitoneal injection of the same volume of saline.Echocardiography was performed every 10min and every 15min after 30min time point until 60min.ResultsAnesthetic agent strikingly brought down heart function of mice.The nadir of heart rate,fractional shortening(FS),cardiac output(CO) occurred during 10-20min period and could not be restored to normal value at baseline even after 60min.Left ventricular end-diastolic diameter(LVEDD) and left ventricular end-systolic diameter(LVESD) increased to maximum at 20min point,then decreased to value at baseline until 60min.LVEDD could be restored to baseline value while LVESD remained larger than baseline at 60min.Coefficient of variation of echocardiographic measurement in non-anesthetic group was smaller than those in anethetic group.FS and heart rate of all mice were highly corrrelated by regression analysis(r=(0.884),P
