Objective:To assess the influe nce of mimic cardiac rate on hydrodynamics of the different mechanical prostheti c cardiac valves.Methods:US-made CarboMedics bile aflet valve and China-made Jiuling bileafle t valve and...Objective:To assess the influe nce of mimic cardiac rate on hydrodynamics of the different mechanical prostheti c cardiac valves.Methods:US-made CarboMedics bile aflet valve and China-made Jiuling bileafle t valve and C-L tilting disc valve have been tested in a pulsatile flow simulat or in the aortic position. The testing condition was set at the mimic cardiac r ate of 55 beats/min,75 beats/min,100beats/min and a constant mimic cardiac out put of 4L/min. The mean pressure differences(ΔP),leakage volumes (LEV) and closi ng volumes(CLV) across each valve,and the effective orifice areas(EOA) have bee n analyzed.Results:Within the range of physiology, the ΔP,LEV and CLV were falling as the increasing of mimic cardiac rate,and the extent of variance was larger. The EOA was increasing with the increase of the mimic cardiac rate. It is a differe nt response as the altering of the cardiac rate for the different type of the me chanical prosthetic cardiac valves.Conclusions:The change of the mimic cardiac rate can affect the hydrodynamics of the mechanical prosthetic cardiac valves. The hydrodynamics of the bileaflet valve prosthesis is better than the tilting disc valve.展开更多
To assess the hemodynamic performance and biocompatibility of China-made solid pyrolytic carbon bileaflet valve prosthesis so as to provide evidences for clinical trial,fifteen sheep aged 5-6 months underwent mitral r...To assess the hemodynamic performance and biocompatibility of China-made solid pyrolytic carbon bileaflet valve prosthesis so as to provide evidences for clinical trial,fifteen sheep aged 5-6 months underwent mitral replacement with 21-mm JiuLing valve under cardiopulmonary bypass. The first ten sheep underwent preliminary study to establish the trial methods and the matching of animal weight and prosthesis size, other five underwent formal experiment. The hemodynamic parameters of the prosthesis were determined by means of open cardiac catheterization and echocardiography intraoperatively and 2.5 years after operation respectively. The biocompatibility was evaluated by observing animal survival and valve thrombosis or thromboembolism.In result,all of the five sheep undergoing formal experiment survived well. There were no any prosthesis-related complications including mechanical valve failures, endocarditis, thrombosis, thromboembolism, and paravalvular leak. The transvalvular gradients were 5.2±1.7mmHg, 6.1±0.3mmHg and 6.8±0.4mmHg, the former was measured by catheterization intraoperatively, the two later were achieved by catheterization and echocardiography respectively 2.5 years after operation. The gradients increased mildly with the marked increase in cardiac output under dobutamine stress.The results of this study demonstrated that the JiuLing valve prosthesis has good biocompatibility and excellent hemodynamic performance.展开更多
文摘Objective:To assess the influe nce of mimic cardiac rate on hydrodynamics of the different mechanical prostheti c cardiac valves.Methods:US-made CarboMedics bile aflet valve and China-made Jiuling bileafle t valve and C-L tilting disc valve have been tested in a pulsatile flow simulat or in the aortic position. The testing condition was set at the mimic cardiac r ate of 55 beats/min,75 beats/min,100beats/min and a constant mimic cardiac out put of 4L/min. The mean pressure differences(ΔP),leakage volumes (LEV) and closi ng volumes(CLV) across each valve,and the effective orifice areas(EOA) have bee n analyzed.Results:Within the range of physiology, the ΔP,LEV and CLV were falling as the increasing of mimic cardiac rate,and the extent of variance was larger. The EOA was increasing with the increase of the mimic cardiac rate. It is a differe nt response as the altering of the cardiac rate for the different type of the me chanical prosthetic cardiac valves.Conclusions:The change of the mimic cardiac rate can affect the hydrodynamics of the mechanical prosthetic cardiac valves. The hydrodynamics of the bileaflet valve prosthesis is better than the tilting disc valve.
文摘To assess the hemodynamic performance and biocompatibility of China-made solid pyrolytic carbon bileaflet valve prosthesis so as to provide evidences for clinical trial,fifteen sheep aged 5-6 months underwent mitral replacement with 21-mm JiuLing valve under cardiopulmonary bypass. The first ten sheep underwent preliminary study to establish the trial methods and the matching of animal weight and prosthesis size, other five underwent formal experiment. The hemodynamic parameters of the prosthesis were determined by means of open cardiac catheterization and echocardiography intraoperatively and 2.5 years after operation respectively. The biocompatibility was evaluated by observing animal survival and valve thrombosis or thromboembolism.In result,all of the five sheep undergoing formal experiment survived well. There were no any prosthesis-related complications including mechanical valve failures, endocarditis, thrombosis, thromboembolism, and paravalvular leak. The transvalvular gradients were 5.2±1.7mmHg, 6.1±0.3mmHg and 6.8±0.4mmHg, the former was measured by catheterization intraoperatively, the two later were achieved by catheterization and echocardiography respectively 2.5 years after operation. The gradients increased mildly with the marked increase in cardiac output under dobutamine stress.The results of this study demonstrated that the JiuLing valve prosthesis has good biocompatibility and excellent hemodynamic performance.
