武内 秀之¹, 長谷川 陽¹, 馬岡 晋¹, 関岡 清次¹, 井阪 直樹¹, 中野 赳¹, 岡田 稔²

Hideyuki TAKEUCHI¹, You HASEGAWA¹, Shi UMAOKA¹, Kiyotsugu SEKIOKA¹, Naoki ISAKA¹, Takesi NAKANO¹, Minoru OKADA²

¹三重大学医学部第一内科, ²名古屋大学工学部情報工学科

¹The First Department Internal Medicine Mie University, ²Faculty of Engineering, Nagoya University

キーワード : Spheroidal index, Mitral regurgitation, Geometrical change, 2-D echocardiology

In order to evaluate left ventricular systolic function in patients with mitral regurgitation, using geometrical index, the relationship between spheroidal index and LV function were investigated in 32 patients and 10 normals. This geometrical index was developed originary calculating standard deviation of tangential direction argument (σ_θ) on LV boundary in longitudinal 2-D echocardiography through a computer processing.
Result: (1) σ_θD and σ_θS were significantly lower in MR III° and IV° than in normal and MR I° or MR II° (p(2) Although σ_θD well correlated with EDV in mild volume overload (r=-0.741), σ_θS did not correlate well with ESV in mild volume overload, but did in severe cases (r=-0.617).
(3) σ_θ correlated with fractional shortening on echocardiography (σ_θD: r=0.623, pσ_θS: r=0.800, pσ_θD: r=0.613, pσ_θS: r=0.692, pThe above results suggest, σ_θS is the more sensitive index of LV systolic function than σ_θD. σ_θS appeared to increase with severity of LV dysfunction and to be a good index for determining the timing of operation.
Furthermore, this method has the following superiorities: (1) sensitive to in the narrow echo window cases. (2) calculation algorithms is independent of the center of gravity, (3) and independent of individual body size, (4) and independent of sampling interval of endocardium.