These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Effect of cutting second-order chordae on in-vivo anterior mitral leaflet compound curvature.
    Author: Rodriguez F, Langer F, Harrington KB, Tibayan FA, Zasio MK, Liang D, Daughters GT, Ingels NB, Miller DC.
    Journal: J Heart Valve Dis; 2005 Sep; 14(5):592-601; discussion 601-2. PubMed ID: 16245497.
    Abstract:
    BACKGROUND AND AIM OF THE STUDY: Leaflet curvature determines leaflet stress. In order to assess the influence of second-order chordae (2 degrees CT) on anterior mitral valve leaflet (AMVL) geometry, AMVL curvature was measured before (Baseline) and after (CUT) cutting the 2 degrees CT. METHODS: Miniature radiopaque markers were sutured onto the AMVL in eight sheep: four along the central-meridian from mid-septal annulus to the free-margin; and one each at the 2 degrees CT insertion. Biplane videofluoroscopic data were acquired (open-chest) before and after CUT. Marker-triplet 3-D coordinates were used to calculate radii-of-curvature at LVPmax along the central-meridian (ROCm) and across the AMVL belly (commissure-commissure axis, ROCc-c). RESULTS: CUT did not change LVPmax (111 +/- 12 versus 106 +/- 11 mmHg; p = 0.19). At baseline, the AMVL central-meridian had compound curvature: Convex to the left ventricle near the annulus (-ROCm) and concave near the free-margin (+ROCm). After CUT, the AMVL flattened: ROCm increased near the annulus (from -1.37 +/- 0.52 to -12.58 +/- 29.04 cm; p = 0.02), but did not change near the edge. In the commissure-commissure axis, ROCc-c was concave to the left ventricle at baseline and increased after CUT in all eight animals. In five sheep, ROCc-c was increased (from 1.93 +/- 1.01 to 2.80 +/- 1.36 cm; p = 0.03), but in three sheep ROCc-c was increased and inverted (from 3.65 +/- 2.17 to -1.72 +/- 0.53 cm; p = 0.03), becoming convex to the left ventricle. CONCLUSION: Compound curvature along the AMVL central-meridian appears to be an intrinsic leaflet property that persists even without support from second-order chordae, whereas concave curvature in the commissure-commissure axis is more dependent on intact second-order chordae. Leaflet compound curvature must be incorporated into future finite element models to characterize leaflet stresses accurately. The importance of second-order chordae in maintaining leaflet shape must be considered during mitral repair. A larger ROC increases leaflet stresses, while reversal of ROC changes tensile stress to compressive stress; this might trigger deleterious leaflet remodeling after chordal cutting.
    [Abstract] [Full Text] [Related] [New Search]