不同程度冠状窦堵塞对缺血心肌的保护作用

Protective effects of different antegrade infusion rate of cardioplegia with various degrees of coronary sinus occlusion on the ischemic myocardium in the isolated rabbit heart

目的采用改良的Ｌａｎｇｅｎｄｏｒｆ离体兔心灌注模型进行经主动脉根部顺行灌注加冠状窦堵塞的心肌保护研究。方法在行主动脉根部灌注停搏液之前堵塞冠状窦，使灌注液返流至冠状动脉梗塞的远端心肌组织。灌注停搏液有４种速度（２、４、６、８ｍｌ·ｋｇ－１·ｍｉｎ－１），冠状窦堵塞有３种水平（不堵、半堵、次全堵）。结果停搏液的灌注速率和主动脉根部压之间有显著的相关性（Ｐ＜０．０１）；冠状窦堵塞对主动脉根部灌注压有正性作用。结论冠状窦次全堵塞、温血停搏液灌注速度（４～６）ｍｌ·ｋｇ－１·ｍｉｎ－１可使冠状窦压力保持在安全范围。

Objective To study the protective effects of antegrade cardioplegia infusion via aortic root and coronary sinus occlusion on the ischemic myocardium. Methods Adult rabbit hearts ( n =18) were infused under the modified Langendorff isolated heart model with 4 cardioplegic infusion rate (2,4,6,8 ml·kg -1 ·min -1 and two degrees of coronary sinus occlusion (CSO, 50% moderate, 85% subtotal occlusion) or without CSO, yielding 12 different combinations. Aortic root infusion pressure (AoP) and coronary sinus pressure (CSP) were measured during each infusion of cardioplegia. Results The cardioplegic infusion rate was markedly related to the AoP ( P <0.01). Occlusion of the coronary sinus changed the normal relationships among infusion rate, AoP and CSP. Each increase of 2 ml·kg -1 ·min -1 in infusion rate from 2 to 8 ml·kg -1 ·min -1 with various degrees of CSO resulted in a significant increase in AoP ( P <0.01). CSO had a positive effect on Aop. Conclusion The induced CSP was safely maintained in the range of 3.3 to 4.7 kPa at the infusion rate of 4 to 6 ml·kg -1 ·min -1 with subtotal CSO.