Desflurane is widely used in cardiac surgery patients due to its beneficial effects , but many studies have shown that desflurane reduces myocardial contractility in a dose-dependent manner, and compromises left ventricular( LV) function We hypothesized that desflurane , even at a clinical dosage, would affects intraoperative LV systolic function in a dose-dependent manner and thus produce significant changes int the TDI profiles of mitral annular velocity.