Hydraulic and Hemodynamic Studies on Blood Flow through the Cardiovascular Stenosis

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概要

• 論文の詳細を見る

• In an orifice flow, turbulence and vortex cause an energy loss of fluid. The pressure drop was largest at 5 to 15 mm distal to the orifice and the hydraulic pressure gradually recovered downstream, but a loss of pressure was observed. In in vivo studies critical stenosis revealed the 25% throat area ratio, and this agreed with other reports. On the other hand, critical stenosis was at the 10% throat area ratio in vitro studies. In the larger groups of the mitral valve area (MVA>0.5 cm^2), C revealed smaller values than 1.0, i.e. it could be suggested that the issuing stream becomes "vena contracta". However, in the smaller groups (MVA≧0.5 cm^2), C was larger than 1.0, therefore it could suggest that the discharge jet stream through the stenotic mitral valve orifice does not become "vena contracta". In hemodynamic consideration on mitral stenosis, results were similar to the in vivo study since critical stenosis of the flow reduction was at the 25% throat area ratio and the flow coefficient showed larger groups (8% throat area ratio). On the contrary, the fact that the flow coefficient showed large values than 1.0 in smaller groups documented the similar results in vitro studies. By Gorlin's formula the discharge coefficient is constant (C=0.7) in mitral stenosis. This study, however, elucidated that the C values were larger than 1.0 in the smaller group of the mitral valve orifice, and so mitral valve area calculated by Gorlin's formula became larger than the actual ones. But Gorlin's formula is considered to be appropriate in case of the mitral valve area which is larger than 0.5 cm^2. Thus, it is considered that the hemodynamic characteristics of mitral stenosis have similarities to the results of both in vivo and in vitro studies and mitral valve area is calculated larger in severe mitral stenosis by Gorlin's formula.

• 社団法人日本循環器学会の論文
• 1977-05-20

著者

• FUJIWARA Hideomi

  The 2nd Department of Internal Medicine,Tokyo Medical and Dental University

• Fujiwara Hideomi

  The 2nd Department Of Internal Medicine Tokyo Medical And Dental University

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