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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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Mechanisms of Expiratory Valves Resistance
American Review of Respiratory Disease, 1988Abstract Expiratory valves are the major source of resistance in ventilator circuits. Some valves, particularly under certain conditions, cause high resistances. To establish the mechanisms of expiratory valve resistance (R), we measured R of 4 commercial valves under several experimental conditions.
R A, Kayaleh, A F, Wilson
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Axial Configuration of the Velopharyngeal Valve and Its Valving Mechanism
The Cleft Palate Craniofacial Journal, 1995The variability of the normal velopharyngeal (VP) closure mechanism was studied by investigating VP anatomy in relation to its closure mechanism in 60 patients. The axial configuration of the VP isthmus, as observed in axial CT scans at rest, was found to be correlated with VP function in terms of its closure patterns in speech as observed by ...
Y, Finkelstein +5 more
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Mechanical heart valve cavitation in patients with bileaflet valves
2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2014Today, the quality of mechanical heart valves is quite high, and implantation has become a routine clinical procedure with a low operative mortality (< 5%). However, patients still face the risks of blood cell damage, thromboembolic events, and material failure of the prosthetic device.
Johansen, Peter +4 more
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