左心室及双心室辅助装置对缺血心肌的影响

Effects of Biventricular and Left Ventricular Assist Devices on Ischemic Myocardium

目的 比较左心室辅助装置 (L VAD)和双心室辅助装置 (BVAD)对缺血心肌再灌注后心脏血流动力学、心肌能量代谢物质和心肌超微结构中线粒体形态的影响。 方法 将 16只绵羊随机分为 L VAD组和 BVAD组 ,每组 8只 ,常温阻断升主动脉 2 5分钟 ,造成双心室缺血损伤的动物模型。结扎右颈内动脉远端 ,在心脏复跳后应用转子泵分别行 L VAD(左心室 -右颈内动脉径路 )和 BVAD(左心室 -右颈内动脉和右心室 -肺动脉径路 )辅助循环 12 0分钟。测定血流动力学、心肌三磷酸腺苷、磷酸肌酸 ,观察心肌超微结构变化。 结果 施行 BVAD或 L VAD辅助循环的同时增加容量负荷能够显著改善心脏血流动力学 ,但 L VAD组右心房压显著高于 BVAD组 (P<0 .0 5 ) ;BVAD组右心室心肌三磷酸腺苷、磷酸肌酸含量和心肌线粒体比表面值均高于 L VAD组 (P<0 .0 5 )。 结论 BVAD比 L VAD更有助于促进双心室缺血损伤心肌的功能恢复。

Objective\ To compare the effects of biventricular assist devices (BVAD) and left ventricular assist devices(LVAD) on enhancing the myocardial recovery in an acute ovine model of global myocardial ischemia. Methods\ Sixteen adult sheep were randomly divided into LVAD group ( n=8) and BVAD group ( n=8) . BVAD group consisted of left ventricle right carotid artery bypass and right ventricle pulmonary artery bypass. Two roller pumps with heat exchanger were used. LVAD group was connected from the apex of left ventricle and returned blood flow to the right carotid artery, and a roller pump. The aorta was clamped 25 minutes to produce a global ischemic injury after cross clamp was released. In both BVAD and LVAD group, the bypass was continued for an additional 120 minutes of reperfusion before further measurements were done. Hemodynamic changes, adenosine triphosphate and creatine phosphate were measured. Myocardial ultrastructure were observed.\ Results LVAD could maintain nearly normal circulation with high right atrial pressure by volume loading. However, BVAD group showed superiority in hemodynamics changes. Adenosine triphosphate and creatine phosphate of the right ventricular myocardium in the BVAD group was higher than that of LVAD group ( P<0.05) . Myocardial ultrastructural damage in BVAD group was milder than that of LVAD group. The data showed that specific surface value of mitochondria of right ventricle myocardium was higher in BVAD group than that of LVAD group ( P<0 05) . Conclusion\ BVAD is superior to LVAD for biventricular global ischemia.