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Chordal force distribution determines systolic mitral leaflet configuration and severity of functional mitral regurgitation


, : Chordal force distribution determines systolic mitral leaflet configuration and severity of functional mitral regurgitation. Journal of the American College of Cardiology 33(3): 843-853

The purpose of this study was to investigate the impact of the chordae tendineae force distribution on systolic mitral leaflet geometry and mitral valve competence in vitro. Functional mitral regurgitation is caused by changes in several elements of the valve apparatus. Interaction among these have to comply with the chordal force distribution defined by the chordal coapting forces (F(c)) created by the transmitral pressure difference, which close the leaflets and the chordal tethering forces (FT) pulling the leaflets apart. Porcine mitral valves (n = 5) were mounted in a left ventricular model where leading edge chordal forces measured by dedicated miniature force transducers were controlled by changing left ventricular pressure and papillary muscle position. Chordae geometry and occlusional leaflet area (OLA) needed to cover the leaflet orifice for a given leaflet configuration were determined by two-dimensional echo and reconstructed three-dimensionally. Occlusional leaflet area was used as expression for incomplete leaflet coaptation. Regurgitant fraction (RF) was measured with an electromagnetic flowmeter. Mixed procedure statistics revealed a linear correlation between the sum of the chordal net forces, sigma[Fc - FT]S, and OLA with regression coefficient (minimum - maximum) beta = -115 to -65 [mm2/N]; p < 0.001 and RF (beta = -0.06 to -0.01 [%/N]; p < 0.001). Increasing FT by papillary muscle malalignment restricted leaflet mobility, resulting in a tented leaflet configuration due to an apical and posterior shift of the coaptation line. Anterior leaflet coapting forces increased due to mitral leaflet remodeling, which generated a nonuniform regurgitant orifice area. Altered chordal force distribution caused functional mitral regurgitation based on tented leaflet configuration as observed clinically.

US$29.90

PMID: 10080490


Other references

Koch, P., 1996: Skin burns, necrosis and caustic ulcers due to wet cement, concrete and lime. Introduction: Skin burns and caustic ulcers caused by wet cement, due to calcium hydroxyde, am rarely reported in the literature. They occur mostly among amateur cement users. Observations: We report seven cases of skin bums, necrosis and ulcerati...

Yin Baolin, 1990: The structural control on fault type thermomineral water in Jiangxi. Shuiwendizhi Gongchengdizhi = Hydrogeology and Engineering Geology 1990(3): 20-22

Nguyen C.H.; Ordahl C.P., 1991: Repression of cardiac troponin t gene expression during skeletal muscle development in chick embryos. Clinical Research 39(1): 46A

Hadayeghi, A.; Shalaby, A.S.; Persaud, B.N.; Cheung, C., 2006: Temporal transferability and updating of zonal level accident prediction models. This paper examines the temporal transferability of the zonal accident prediction models by using appropriate evaluation measures of predictive performance to assess whether the relationship between the dependent and independent variables holds re...

Taneja, G.C.; Bhatnager, D.S., 1959: Heritability and repeatability of milk yield in Malvi cattle. Based on 300-day 1st and 2nd lactation milk yields of 44 daughter-dam pairs of Malvi cows, heritability and repeatability were estimated to be 0.43 +or- 0.20 and 0.76 +or- 0.20 resp.

Muller, E., 1962: Genetlcal problems of hereditary hygiene in the practical breeding of cattle 12th International session on artificial insemination of domestic animals, 1962 Abstract. Schweiz Arch Tierheilk 104(10): 625

Gould, I.A.; Skiver, F.M., 1945: Lactic acid and titratable acidity of commercial dried and evaporated milk in Michigan. Results are presented of lactic acid and titratable acidity measurements on 35 samples of dry milk solids (not over 1.5% fat) and on 18 samples of evaporated milk. The av. lactic acid content of 15 summer samples of the dry milk was 0.018%; for 20...

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