van der Veen F H, van der Vusse G J, Flameng W, Coumans W A, Reneman R S
Department of Physiology, University of Limburg, Maastricht, The Netherlands.
Cardiovasc Res. 1989 Jun;23(6):468-71. doi: 10.1093/cvr/23.6.468.
Knowledge of the effects of cardiopulmonary bypass on the myocardium and on cardiac function is limited. We therefore studied changes in haemodynamics and myocardial metabolism during the initial phase of cardiopulmonary bypass in two patient groups. In one group "normothermia" (34 degrees C) was used while on bypass, with an empty beating heart; in the other group hypothermia (range 27-33 degrees C) with ventricular fibrillation was used. Mean aortic pressure and myocardial oxygen consumption decreased significantly in both groups after instalment of CPB. The arterial-coronary sinus differences in lactate changed to negative values within 5 min of the start of bypass, indicating release instead of uptake of lactate. This release was maintained during the observation period and increased significantly in the hypothermic patient group when the ventricles were fibrillating. Therefore in patients undergoing aorto-coronary bypass surgery, detrimental changes in the myocardium must be anticipated during the initial phase of cardiopulmonary bypass prior to aortic cross clamping.
关于体外循环对心肌和心功能影响的认识有限。因此，我们研究了两组患者在体外循环初始阶段的血流动力学和心肌代谢变化。一组在体外循环期间采用“常温”（34摄氏度），心脏空跳；另一组采用低温（27 - 33摄氏度）并伴有心室颤动。在安装体外循环后，两组患者的平均主动脉压和心肌耗氧量均显著下降。体外循环开始后5分钟内，动脉 - 冠状窦乳酸差值变为负值，表明乳酸释放而非摄取。这种释放在观察期内持续存在，并且在低温患者组心室颤动时显著增加。因此，在接受主动脉 - 冠状动脉搭桥手术的患者中，在主动脉阻断前的体外循环初始阶段，必须预见到心肌的有害变化。
