It is a matter of force. It is a balance of valve closing force and tethering force that affects mitral valve coaptation. Ischemic mitral regurgitation develops secondary to left ventricular dysfunction generally with structurally normal leaflets. However, it seems it is not simply a matter of force when we see the fact that valve leaflets histologically change after myocardial infarction. The ...

An implantable manually-actuated drug delivery device, consisting of a refillable drug reservoir, flexible cannula, check valve, and suture tabs, was investigated as a new approach for delivering pharmaceuticals to treat chronic ocular diseases. Devices are fabricated by molding and bonding three structured layers of polydimethylsiloxane. A 30 gauge non-coring needle was used to refill the rese...

Due to their ease of fabrication, facile use and low cost, ice valves have great potential for use in microfluidic platforms. For this to be possible, a rapid response speed is key and hence there is still much scope for improvement in current ice valve technology. Therefore, in this study, an ice valve with enhanced thermal conductivity and a movable refrigeration source has been developed. An...

Doubt has been cast upon the valvular origin of the first heart sound since the finding of a delay between the cross-over of the ventricular and atrial pressure tracings and the sound attributed to closing ofthe corresponding atrio-ventricular valve. There is a similar delay after the left ventricular pressure falls below that in the left atrium before the occurrence of the opening snap in mitr...

Analytical solutions to the time-dependent, nonlinear equation governing incompressible, one dimensional flow in a pipe are presented. The flow is pressure-driven, and a valve on the pipe controls the flow rate. Power-law losses and an exponential closing action of a valve are assumed. Four different approximation methods are used. Of these, perturbation and Adomian’s decomposition are seen to ...

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. ...

Although classic and standard procedure for patients with ascending Aorta aneurysm with Sever aortic Regurgitation is Bentall surgery but in some selected cases this complex surgery was not performed with different reason like advanced age and coexisting comorbidity involving renal and hepatic and lung Function. In our cases 75 years old man with chronic renal failure ( Cr= 3.2 ) who was known ...

In support of our disruption mitigation profram, a fast gas valve has been constructed and tested on TEXTOR at FZJ Juelich. Its main features have been shown to be: ~1! rapid response time: 0.5 ms; ~2! amount of injected gas: variable, 2–1000 mbar3l; ~3! linear dependence of the number of injected particles on the gas pressure; ~4! capability of working in a strong magnetic field; ~5! sort of g...

Motion and position of both mitral leaflets were studied in five normal dogs 1-11 wk after radiopaque markers were sutured on the valve cusps and on the mitral annulus. Cinefluorograms and cineangiograms (100-120 frames/s) of left atrium and left ventricle were used to study cusp motion and intraventricular flow patterns, and to detect mitral regurgitation during sinus rhythm (42-184 beats/min)...

Background: Beta-thalassemia major is a severe and lethal hemolytic anemia. Regular transfusion is necessary for avoidance of its complications but it may end to cardiac involvement secondary to iron overload. Angiotensin converting enzyme inhibitors (ACEIs) are useful medications even in early stages of heart failure. We studied the effects of two common ACEIs on improvement of heart function ...