title: [New method for estimating left ventricular myocardial elasticity by vibration analysis].
abstract: We solved numerical solutions of Advani-Lee's equation, which treats free vibrations of fluid-filled spherical shells, and forms the basis for non-invasive estimation of left ventricular myocardial elasticity. Numerical results showed that elasticity is approximated by E = 86.5.a2.f2 (E: elasticity (dyn/cm2), a: internal radius (cm), f: eigen-frequency (Hz)). To examine the accuracy of this theoretical equation in estimating elasticity, we made 7 spherical shells of silicone rubber, and compared the estimated elasticity by this equation with that by a standard stretch test. The elasticity calculated by Advani-Lee's equation and by stretch test proved to be nearly identical. Therefore, we concluded that we can estimate the elasticity of a spherical shell using this equation. We calculated the myocardial elasticity at the first heart sound emission in 25 normal persons with a simplified (approximated form of) Advani-Lee's equation. The mean elasticity in normal subjects was (7.04 +/- 2.46) x 10(5) dyn/cm2.
authors.affiliation: First Department of Internal Medicine, Tohoku University School of Medicine, Aoba-ku Sendai.
authors.forename: H
authors.initials: H
authors.lastname: Honda
authors.forename: Y
authors.initials: Y
authors.lastname: Koiwa
authors.forename: T
authors.initials: T
authors.lastname: Ohyama
authors.forename: T
authors.initials: T
authors.lastname: Takagi
authors.forename: J
authors.initials: J
authors.lastname: Kikuchi
authors.forename: N
authors.initials: N
authors.lastname: Hoshi
authors.forename: J P
authors.initials: JP
authors.lastname: Butler
authors.forename: T
authors.initials: T
authors.lastname: Takishima
mesh_terms: D004548:Elasticity; D006334:Heart Function Tests / Q000379:methods*; D006347:Heart Sounds; D006801:Humans; D016277:Ventricular Function, Left; D014732:Vibration