THIS REPORT presents evidence that lymphatics are present in the mitral valve of the dog. This observation, if it can be translated to man, may be of significance in valvulitis. Histological studies in the past have failed to solve the problem of whether or not lymphatics are present in the heart valves of man or animals. Eberth and Belajeff, in 1866, reported finding a subendocardial plexus of...

C ALCIUM deposition in diseased heart valves may be demonstrated frequently in necropsy studies, but these deposits are usually overlooked clinicaIIy unless the heart is carefuIly examined roentgenographically. Sosman1 discusses in detail a simple method of demonstrating the presence of calcific deposits within the heart by x-ray. He suggests a small fluoroscopic aperture and a screen of high i...

Cardiac valves are dynamic structures, exhibiting a highly specialized architecture consisting of cells and extracellular matrix with a relevant proteoglycan and glycosaminoglycan content, collagen and elastic fibers. Biological valve substitutes are obtained from xenogenic cardiac and pericardial tissues. To overcome the limits of such non viable substitutes, tissue engineering approaches emer...

Collagen synthesis and collagenase activity of cryopreserved heart valves

The anisotropic property of porcine aortic valve leaflet has potentially significant effects on its mechanical behaviour and the failure mechanisms. However, due to its complex nature, testing and modelling the anisotropic porcine aortic valves remains a continuing challenge to date. This study has developed a nonlinear anisotropic finite element model for porcine heart valves. The model is bas...

Although magnetic resonance imaging (MRI) is capable of imaging various physiological parameters associated with the heart valves, it has generally been difficult to visualize the valve leaflets directly. The aortic valve was imaged in 120 patients referred for cardiac MRI to assess myocardial volumes or mass. The average patient age was 37 and ranged from 9 to 75 years. Heart rate ranged from ...

Autoimmune inflammatory reactions leading to rheumatic fever (RF) and rheumatic heart disease (RHD) result from untreated Streptococcus pyogenes throat infections in individuals who exhibit genetic susceptibility. Immune effector mechanisms have been described that lead to heart tissue damage culminating in mitral and aortic valve dysfunctions. In myxomatous valve degeneration (MXD), the mitral...

Heart valves are elaborate and highly heterogeneous structures of the circulatory system. Despite the well accepted relationship between the structural and mechanical anisotropy and the optimal function of the valves, most approaches to create tissue-engineered heart valves (TEHVs) do not try to mimic this complexity and rely on one homogenous combination of cells and materials for the whole co...

In general, heart specimens for anatomic study are dissected to Visualize the coronary arteries and/or myocardium. To study the cardiac valves, the dissection is performed in a way that permits Visualization of the valves and their relationship to each other and adjacent structures. In either case, it is difficult to make permanent specimens, free of fixatives for safe handling, that remain ope...