The speed of closure of the mitral valve during diastole, as recorded by ultrasonocardiography, is reduced in patients with mitral stenosis. A pattern of movement similar to that of severe mitral stenosis is seen in recordingsfrom patients with normally functioning mitral Starr-Edwards prostheses. Simultaneous ultrasound recordings of ball and cage movements show that the prosthetic valve remai...

SINCE the introduction of artificial heart valves, investigators have been continuously modifying them, endeavoring to eliminate complications associated with their use. -3 The Starr-Edwards ball-valve prosthesis was the first to be widely accepted; however, problems due to its weight, cage size, and resistance to blood flow have stimulated the search for a better prosthetic device. In spite of...

SINCE the introduction of artificial heart valves, investigators have been continuously modifying them, endeavoring to eliminate complications associated with their use. -3 The Starr-Edwards ball-valve prosthesis was the first to be widely accepted; however, problems due to its weight, cage size, and resistance to blood flow have stimulated the search for a better prosthetic device. In spite of...

C atheter assessment of Starr-Edwards prosthetic aortic valve stenosis requires simultaneous recording of left ventricular (LV) and aortic pressures. Passage of conventional Dacron catheters across mechanical valves can damage the mechanism and induce valvar incompetence. The alternative Bockenbrough procedure requires atrial septal puncture with potential lethal complications. The availability...

In some applications, especially for the attitude control of navigation system, the friction moment of instrument ball bearings is one of the much more important factors. Its magnitude and fluctuation affect not only the energy transfer but also the accuracy of signal transfer even though the bearings work at very low speed. Experimental analysis showed that the cage rotated with a minor fluctu...

1. The haemolytic complications of Starr-Edwards ball and cage prostheses have been studied in ninety-five patients. 2. Intravascular haemolysis has been found to be common and particularly marked after an aortic valve replacement. 3. A simple and reliable method for estimating urinary iron is described, and excessive urinary iron loss was found to be common especially in aortic valve replaceme...

Long-term clinical and laboratory findings in three children who required mitral valve replacement below age four years are reported. In each instance a second valve replacement was necessary approximately 8 1/2 years after the initial one, following a two and one-half fold increase in body weight. Inadequate mitral valve orifice size was found in each instance, producing a hemodynamic picture ...

Developmental efforts to achieve percutaneous catheterbased therapies for cardiac valve repair and replacement have advanced rapidly over the past several years. A variety of methods to treat mitral regurgitation (MR) and to replace aortic and pulmonic valves have already been successfully employed in patients. These innovative clinical transcatheter valve therapies were anticipated more than a...

introduction: rheumatic heart disease still remains one of the leading causes of congestive heart failure and death owing to valvular pathologies, in developing countries. valve replacement still remains the treatment of choice in such patients.the aim of this study wasto analyze the postoperative outcome of  double valve replacement (mitral and aortic ) in patients of rheumatic heart disease. ...