Several diseases have been acknowledged as pathological causes for mitral valve stenosis (MS), of which rheumatic heart disease is the most prevalent. Rheumatic heart disease is a chronic manifestation of rheumatic carditis, which occurs in 60% to 90% of cases of rheumatic fever. Rheumatic fever is a late sequela to Group A -hemolytic streptococcal infection of the throat. The initial rheumatic...

Cardiac valves function in a mechanically complex environment, opening and closing close to a billion times during the average human lifetime, experiencing transvalvular pressures and pulsatile and oscillatory shear stresses, as well as bending and axial stress. Although valves were originally thought to be passive pieces of tissue, recent evidence points to an intimate interplay between the he...

We report on an electrical microfluidic pressure gauge. A polydimethylsiloxane microvalve closes at a characteristic applied pressure determined by the material's properties and the valve's dimensions. Hence, when the same pressure is applied to all valves of a heterogeneous valve array, some valves close while others remain open. The state of the array is combined with knowledge of the respect...

The echocardiographic findings of eight patients with hypertrophic cardiomyopathy without outflow obstruction (HMC) and of 15 normal (Norm) individuals are presented. The characteristic features in HMC were: (1) interventricular septal width much greater than normal (HMC= 2.5 + 0.3 cm, Norm = 1.0 + 0.2 cm, P <0.005); (2) normal or only slightly increased posterior left ventricular wall thicknes...

purpose: to evaluate the effect of early aqueous suppressants initiation on ahmed glaucoma valve success rate. methods: in this randomized clinical trial, a total of 94 eyes of 94 patients with refractory glaucoma were enrolled. the eyes were randomly selected into 2 groups. in group 1 (n=47), patients received early topical combination of timolol-dorzolamide twice daily after ahmed glaucoma va...

Native Aortic Valve Leaflets Chi Zheng, M1 University of Pittsburgh; BSE University of Michigan In association with: John A. Stella and Michael S. Sacks, Ph. D. Department of Bioengineering, University of Pittsburgh June.16.2006 Introduction The mammalian heart is a four-chambered pulsating pump that circulates the blood within two parallel loops: the systemic and the pulmonary circulation. Blo...

background: this study was undertaken to compare the outcome in patients with moderate to severe ischemic mitral regurgitation (imr) undergoing coronary artery bypass grafting (cabg) with either mitral valve repair or mitral valve replacement. methods: between march 2002 and february 2005, 49 consecutive patients (mean age: 62.84±8.42 years; mean euroscore: 10.03±3.12) with coronary artery dise...

By using an axisymmetric model, we numerically investigate the underlying fluid dynamics of a salp-like swimmer consisting deformable shell, front valve, and back valve. Through coordinated shell inflation/deflation valve opening/closing, uni-directional flow is created inside body in wake, which provides thrust for forward motion. Our results prove that this method capable sustained locomotion...