人工心瓣在脉动循环模拟系统上的能量损耗的研究

In Vitro Study of Energy Losses of Heart Valve Prostheses in Aortic Position

本文对常用的不同尺寸的５种人工心瓣在脉动循环系统的主动脉瓣位，在不同的心率，心输出量和主动脉平均压下进行能量损耗（Ｅｎｅｒｇｙｌｏｓｓｅｓ）的评价。人工心瓣的能量损耗据所计录的左心室压，主动脉压，前向和反向的跨瓣流量而计算。结果表明，跨瓣压差（ΔＰ）随心输出量（ＣＯ）的增加而增加，随心率（ＨＲ）和心瓣尺寸（ＶＳ）的增加而减小；跨瓣反流量（Ｒｅｇ）随ＶＳ的增加而增加，且除笼球瓣外，Ｒｅｇ随ＣＯ的增加而减小；主动脉平均压（ＡＰ）对ΔＰ和Ｒｅｇ的影响较小。人工心瓣的总能量损耗（Ｅｌｔｏｔ）随ＨＲ、ＡＰ和ＶＳ的增加而减小。组织瓣和笼球瓣的Ｅｌｔｏｔ随ＣＯ的增加而增加；斜碟辩和双小叶瓣在低ＣＯ（２．０Ｌ／ｍ）和高ＣＯ（８．０Ｌ／ｍ）时有相对较大的能量损耗。组织瓣中，心包瓣比猪心瓣的Ｅｌｔｏｔ小；机械瓣中，除在ＣＯ中为２．０Ｌ／ｍ和ＨＲ为１００ｂｐｍ的条件下，笼球瓣的Ｅｌｔｏｔ比斜碟瓣和双小叶瓣的Ｅｌｔｏｔ高。

The performance of five types of different size (VS) of heart valve prostheses in the aortic position is assessed based on the in vitro energy losses of valves. A pulse duplicator system was used to test valves under different cardiac output (CO),heart rate (HR)and mean aortic pressure (AP). The energy losses (EL)of valves were calculated from the recorded ventricular and aortic pressure,as well as forward and reverse flows. The results show that transvalvular pressure difference increases with increasing CO,and decreases with increasing HR and VS ; transvalvular regurgitation increases with increasing VS,and decreases with increasing CO except that of StarrEdwards Silastic ball valve (SE) ;AP has litter effect on transvalvular pressure difference and regurgitation. However, the total energy loss (ELtot )of valves decreases with increasing HR,AP and VS,and the ELtot of tissue valves and Stars-Edwards valve increases with increasing CO,but Bjork -Shiley Monostrut and St Jude Medical valves have a higher ELtot at 2. 0 L/m and 8. 0 L/m of CO than at 4. 0 L/m and 6. 0 L/m of CO. In any condition ,for the tissue valve,Sorin-Pericarbon (SP)pericardial valve has a lower ELtot than Carpentier-Edwards (CE) porcine valve does;for the mechanical valve,the SE has a higher ELtot than Bjork-Shiley Monostrut (BS)and St Jude Medical (SJ)do except at 2. 0 L/m of CO and 100 bpm of HR.