[Dynamic and cinematic evaluation of the function of bioprosthesis in the aortic position: tester of cardiac valves].

Twenty four pericardial valvular prostheses were tested in a valvular tester device. The valves considered were: 12 valves of the model that has being already in clinical use, manufactured in the Instituto Nacional de Cardiología "Ignacio Chávez", (INC II) and 12 valves of a model in an experimental stage, (PRT I.) The inner diameter in the two group considered were: 17, 19 and 21 mm. All the valves were tested in the aortic position in the valvular tester device. Behavior of the valvular prostheses were examined at various rates of pulsation, 60, 77, 105 and 159 per minute, with an ejection volume of 70 and 80 ml (range of flows between 4200 and 12720 ml min1). The pressure of the ventricular and aortic cameras were registered continuously, by external transducers, and in the other hand, the kinetic of the valves and the degree of opening were evaluated for direct view trough an special window. The grade of incompetence was too evaluated and expressed in percent of the stroke volume. The transvalvular pressure gradient was lower in INC II model valves, specially at moderate and high flows, and at same time had a largest functional area. The degree of incompetence was higher in the 19 and 21 mm diameter valvular subgroups than the same subgroups in the PRT I model. In relation to the 17 mm subgroup, significant differences were not find. The use of the valvular tester showed a basic utility in the hydrodynamic evaluation of the news bioprostheses design, and so in the quality control of the valves than has being manufacturing.