改良Dennis左心机械辅助循环方法的血流动力学研究

Study on Blood Flow Dynamics of Reforming Dennis′ Left Ventricular Assist

目的：改良Ｄｅｎｎｉｓ左心机械辅助循环（简称左心辅助循环）方法，使其能应用于心脏术后因严重左心衰竭不能脱离体外循环机者，在此对该左心辅助循环方法进行血流动力学研究，以便评价其性能。方法：直视穿刺心房间隔卵圆窝，将引流管送入左心房内，左心辅助循环转流率在４０ｍｌｋｇ－１／ｍｉｎ、７０ｍｌｋｇ－１／ｍｉｎ、１００ｍｌｋｇ－１／ｍｉｎ条件下测心脏血流动力学改变。结果：随左心辅助循环转流率增加，左心房、心室压及压力变化速率逐渐下降（Ｐ＜０．０５），对右心房、心室压、压力变化速率、平均肺动脉压、主动脉收缩压及肾动脉血流量影响不明显（Ｐ＞０．０５）；主动脉舒张压、右心室输出量及右颈总动脉血流量逐渐升高（Ｐ分别＜０．０５，＜０．０５，＜０．０１）；左心室输出量逐渐减少（Ｐ＜０．０５）。结论：该方法能有效地降低左心前负荷；左心辅助循环转流率在７０ｍｌｋｇ－１／ｍｉｎ、１００ｍｌｋｇ－１／ｍｉｎ时能维持适当的体循环。

Objective:To assess the new method of establishing left ventricular assist by systemic hemodynamics. Methods:The fossa ovalis of atrial septum was punctured visually and draining tube was sent into left atrium.Then cardiac hemodynamic change was measured at assist ratio of 40 ml·kg -1 /min,70 ml·kg -1 /min,100 ml·kg -1 /min,respectively. Results:As the assist ratio increased,the left atrial and ventricular pressure and left ventricular outflow decreased( p <0 05),whereas the aortic diastolic pressure,outflow of right ventricle and right carotid flow increased( p <0 05);The right atrial and ventricular pressure,mean pulmonary arterial pressure,aortic systolic pressure and renal arterial flow did not chang( p >0 05). Conclusion:The new method can decrease the preload of left heart effectively and maintain the systemic circulation properly at assist ratio of 70 ml·kg -1 /min,100 ml·kg -1 /min.