MECHANICAL PROPERTIES OF CHORDAE TENDINEAE OF THE MITRAL HEART VALVE: YOUNG’S MODULUS, STRUCTURAL STIFFNESS, AND EFFECTS OF AGING

摘要

Young’s modulus and structural stiffness were determined for chordae tendineae of thenmitral valve from young (18–26 weeks) and old (over 2 years) porcine hearts. For chordaenfrom the posterior leaflet of the valve, the Young’s modulus values were significantlynhigher (p < 0.05) for the thinner marginal chordae (59 ± 31MPa young; 88 ± 21MPanold) than for the thicker basal chordae (31 ± 4MPa young; 28 ± 9MPa old). Marginalnchordae (both anterior and posterior) had significantly higher (p < 0.05) value for theirnYoung’s modulus in old (88 ± 21MPa anterior and posterior) than in young (62 ±n17MPa anterior, 59 ± 18MPa posterior) pig hearts. There was no significant differencenin structural stiffness between marginal and basal (anterior and posterior leaflets) ornbetween strut chordae (that are associated with anterior the leaflet only) and marginalnand basal chordae. However, the value of structural stiffness of chordae was significantlynhigher (p < 0.05) for old (2.2 ± 0.2 kN/m) than for young (2.0 ± 0.4 kN/m) chordae.nThese results show that aging affects the properties of chordae and that all chordae neednto be included in finite element models of valve function.