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Mechanical heart valve prostheses
Cardiovascular Pathology, 2003Abstract Mechanical heart value prostheses have been in use since the 1950s. Many prostheses have been used for a while and then discontinued. Today, there are a large number and variety of prostheses in use and an even larger variety that are in place in patients. These may be explanted at any time for a number of reasons.
Jagdish Butany +8 more
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Mechanism of Closure of the Aortic Valve
Nature, 1968THE human aortic valve consists of three cusps made of relatively inelastic, muscle-free material about 0.15 mm thick. It opens and shuts about once a second, and withstands a pressure difference of 100 mm of mercury when closed. It usually functions for 70 yr without failure, and works so efficiently that very little blood is regurgitated at each ...
B J, Bellhouse, F H, Bellhouse
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Mechanical Heart Valves in Children
Scandinavian Journal of Thoracic and Cardiovascular Surgery, 1984Longterm follow-up of 17 children, who consecutively underwent replacement of one cardiac valve with the Björk-Shiley prosthesis, is presented. The children's mean age was 8 years (range 4-12 years) and body weight 23.5 kg (range 15.0-38.4 kg) at the time of surgery 1970-80. Nine of the 17 operations (53%) were second-stage cardiac surgery.
A, Henze, D, Lindblom, V O, Björk
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Impact of calcific aortic valve disease on valve mechanics
Biomechanics and Modeling in Mechanobiology, 2021The aortic valve is a highly dynamic structure characterized by a transvalvular flow that is unsteady, pulsatile, and characterized by episodes of forward and reverse flow patterns. Calcific aortic valve disease (CAVD) resulting in compromised valve function and increased pressure overload on the ventricle potentially leading to heart failure if ...
Brennan J. Vogl +4 more
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Mechanical Decalcification of the Aortic Valve
The Annals of Thoracic Surgery, 1986Thromboembolism and anticoagulant-related complications secondary to prosthetic aortic valve replacement constitute a significant risk (28% at 5 years). From 1978 through 1984, decalcification of the aortic valve was performed in 8 patients who were undergoing coronary artery revascularization.
R M, King +3 more
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Mechanism of the movements of the atrioventricular valves
The American Journal of Cardiology, 1966Abstract Ventricular pressure, ventricular diameter, atrial pressure, the pressure gradient across the A-V valve, and intraventricular heart sounds were recorded. The mechanisms producing closing and opening of the A-V valve were analyzed. There were two producing A-V valve closure. (1) Atrial contraction normally produces presystolic closure of the A-
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Fluid Mechanics of the Mitral Valve
Nature, 1969THE exploitation of trapped vortices and flow deceleration by the aortic valve to ensure maximum efficiency and to make possible laminar flow1,2 suggests a similar mechanism for the atrio-ventricular valves. These are the inlet valves to the two ventricles, the mitral valve on the left side and the tricuspid valve on the right.
B J, Bellhouse, F H, Bellhouse
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Evolution of mechanical heart valves
The Annals of Thoracic Surgery, 2000The need for prosthetic heart valves was long recognized but seemed an impossible dream before 1952 when Dr Charles Hufnagel clinically introduced a ball valve that he placed into the descending thoracic aorta for treatment of aortic valvular insufficiency.
R A, DeWall, N, Qasim, L, Carr
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Mechanisms of aortic valve calcification
The American Journal of Cardiology, 2004The calcified aortic valve lesion develops in the setting of endothelial injury and inflammation and displays hallmarks of atherosclerosis, including lipids accumulation, matrix metalloproteinase activation, and interaction with renin-angiotensin system.
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Mechanical Heart Valves in Septuagenarians
Journal of Cardiac Surgery, 2008To report on the use of a third-generation bileaflet mechanical valve in septuagenarians, selected to receive a mechanical valve, as compared to (a) a younger cohort undergoing same valve implant (study 1) and to (b) a matched group of septuagenarians undergoing biological implant (study 2).The study was carried out in a tertiary regional hospital in ...
Ascione, R +5 more
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