Study on different myocardial protection methods in cardiac valve replacement

Objective: To evaluated the effective of myocardial protection of three perfusion methods in cardiac valve replacement under Extracorporeal Circulation （ECC) Methods: 53 patients were divided into three groups. Group1 received cold crystalloid cardioplegia induction, group 2 were perfused with 4:1 blood cardioplegia, group 3 received continuous warm blood retrograde perfusion. Results: The total volume and hemodilution of group 2 and group 3 were lower than group 1, but the temperature was higher than group 1, there were significantly difference （P＜0.05) The perfusion volume of crystalloid cardioplegia and blood k⁺ of group 1 were higher than group 2 （P＜0.05) The rate of auto-resuscitation was lower than group 2 （P＜0.05) The ECC total volume and aortic clam time in group3 were lower than that in group2 and group1 （P＜0.05) The post operative LVEF decreased slightly in group2 and group3 （P＞0.05), but decreased significantly in group1 （P＜0.05) Conclusion: crystalloid cardioplegia was convenient to use for myocardial protection, but it was not satisfied for sickly patients with dysfunction of left ventricle 4:1 cold blood cardioplegia and normal thermia ECC with retrograde perfusion without cardiac arrest can provide the energy for myocardial, therefore, it was benefit for valve replacement