Objective: Forty cases of cardiac valve replacement on beating heart with mild hypothermia and cardiopulmonary bypass were performed and the related issues with myocardioprotective effect and air embolism during surgery investigated. Methods: Conventional cardiopulmonary bypass was established

the body temperature was maintained at 32~33℃

and the mitral valve replacement was performed on slow beating heart. The arotic valve replacement was performed under coronary sinus retrogade perfusion on beating heart with the aorta cross-clamped. Results: There was no operative mortality. Air embolism and low output syndrome were avoided. Conclusion: Through our practice

we think an optimal myocardioprotective effect during surgery could be made by this new technique

and air embolism could be avoided if a proper method of expelling is used.