左心辅助对犬缺血右心室的影响

Effects of left heart support on ischemic right ventricle in dogs

目的 观察左心辅助对缺血右心室的影响。方法 2 0条健康犬按不同左心辅助流量随机分为 4组 :Ⅰ组 :对照组 ;Ⅱ组 :辅助流量为 5 0ml·kg-1·min-1;Ⅲ组 :辅助流量为 70ml·kg-1·min-1;Ⅳ组 :辅助流量为 90ml·kg-1·min-1。结扎右冠状动脉 8min ,应用气动左心辅助装置行左心房至升主动脉辅助 3h。观察右心血流动力学及右心室心肌ATP、心肌超微结构的变化。结果 与对照组相比 ,阻断右冠状动脉近端 (RCA)前 ,Ⅱ、Ⅲ、Ⅳ组各项动力学指标差异均无显著性 (P >0 .0 5 ) ,阻断RCA 8min ,Ⅱ、Ⅲ组右心室最大压力上升速率 (Rvdp/dtmax)减小 (P <0 .0 5 ) ,全肺阻力(TPR)降低 (P <0 .0 5 ) ,右心排血量 (RCI)及ATP含量差异无显著性 (P >0 .0 5 ) ,心肌超微结构的变化大致相似。Ⅳ组Rvdp/dtmax减小 ,TPR升高 ,RCI减少 ,ATP含量降低 (P值均 <0 .0 1) ,心肌超微结构病变加重。结论 高流量左心辅助导致缺血右心室的功能恶化衰竭。

Objective\ To investigate the effects of left heart support on ischemic right ventricle. Methods\ Twenty dogs were randomly divided into 4 groups according to different assist flow: group Ⅰ (control group), group Ⅱ (50 ml·kg -1 ·min -1 ), group Ⅲ (70 ml·kg -1 ·min -1 ), group Ⅳ (90 ml·kg -1 ·min -1 ). Right coronary artery of each dog was clamped for 8 min. Then left heart support with a pneumatic driven diaphram type left ventricular assist device was carried out for 3 h by left atrial to ascending aorto by pass. The function of right heart and ATP content and myocardium ultrastruture were examined. Results\ Rvdp/dtmax and TPR were decreased ( P <0.05), but RCI and ATP contents had no significant change ( P >0.05) in group Ⅱ and group Ⅲ as compared with group Ⅰ. For group Ⅳ, TPR was increased ( P <0.01), Rvdp/dtmax and RCI and ATP contents were significantly decreased ( P <0.01), the worst changes in ultrastructure were observed. Conclusion\ Left heart support with higher assist flow can cause function of ischemic right ventricle deterioration and failure.\;