SUMMARY The Lillehei-Kaster (L-K) valve is a tilting disc prosthesis currently in use for heart valve replacement. We report data from phonocardiography (PHONO) and echocardiography (ECHO) in 20 patients with a normally functioning mitral valve prosthesis (MVP). The MVP is well recorded by ECHO, resembling a mitral stenosis pattern with a disc excursion of 7 to 12 mm and a mean opening and clos...

BACKGROUND Congenital pulmonary valve stenosis and patent ductus arteriosus are common congenital heart defects in dogs. However, concurrence of atypical pulmonary valve stenosis and patent ductus arteriosus is uncommon. This report describes the anatomic, histopathologic, and echocardiographic features in a dog with concomitant pulmonary valve stenosis and patent ductus arteriosus with atypica...

BACKGROUND The surgical approach to aortic root aneurysm and/or dissection remains controversial. The use of valve-sparing operations, which are thought to have many advantages, is increasing. We hypothesized that the particular technique and type of surgery could influence valve motion characteristics and function. Therefore, we studied the instantaneous opening and closing characteristics of ...

Pulmonary autograft valve replacement has been simulated by implanting the pulmonary valve into the aortic position of the same cadaver heart from both human and porcine sources. The forces acting on the pulmonary valve leaflets have been calculated on the basis of a triaxial ellipsoid mathematical model. These forces on the pulmonary autograft valve were shown to be essentially similar to thos...

This paper developed a 3D physical model of the hydraulic end high-pressure liquid hydrogen reciprocating pump to research dynamic characteristics valve system. Based on mesh technology, we analyzed coupling and plunger motion spool force considering leakage model, closure gap, compressibility hydrogen. Further, effect spring stiffness preload laws valve. Finally, pressurization test was conduc...