Annals of Biomedical Engineering

, Volume 31, Issue 10, pp 1171–1181 | Cite as

Effects of a Saddle Shaped Annulus on Mitral Valve Function and Chordal Force Distribution: An In Vitro Study

  • Jorge Hernan Jimenez
  • Dennis Dam Soerensen
  • Zhaoming He
  • Shengqiu He
  • Ajit P. Yoganathan
Article

Abstract

Studies have concluded that the shape of the human mitral valve annulus is a three-dimensional saddle. The objective of this study was to investigate the effects of a saddle shaped annulus on chordal force distribution and mitral valve function. Eleven human mitral valves were studied in a physiological left heart simulator with a variable shaped annulus (flat versus saddle). Cardiac output and transmitral pressure were analyzed to determine mitral regurgitation volume. In six experiments, force transducers were placed on six chordae tendineae to measure chordal force distribution. Valves were tested in normal and pathophysiologic papillary muscle positions. When comparing the flat and saddle shaped configurations, there was no significant difference in mitral regurgitation volume 11.2% ± 24.7% (p=0.17). In the saddle shaped configuration, the tension on the anterior strut chord was reduced 18.5% #x00B1 16.1% (p < 0.02), the tension on the posterior intermediate chord increased 22.3% #x00B1 17.1% (p < 0.03), and the tension of the commissural chord increased 59.0% #x00B1 32.2% (p < 0.01). Annular shape also altered the tensions on the remaining chords. Annular shape alone does not significantly affect mitral regurgitation caused by papillary muscle displacement. A saddle shaped annulus redistributes the forces on the chords by altering coaptation geometry, leading to an optimally balanced anatomic/physiologic configuration. © 2003 Biomedical Engineering Society.

PAC2003: 8719Hh, 8719Uv, 8719Rr

Mitral regurgitation Chordal force Annulus shape 

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References

  1. 1.
    Aikawa, K., F. H. Sheehan, C. M. Otto, K. Coady, G. Basheim, and L. Bolson. The severity of functional mitral regurgitation depends on the shape of the mitral apparatus: A three-dimensional echo analysis. J. Heart Valve Dis. 11:627–636, 2002.Google Scholar
  2. 2.
    Arts, T., S. Meerbaum, and R. Reneman. Stresses in the closed mitral valve: A model study. J. Biomech. 16:539–547, 1983.Google Scholar
  3. 3.
    Boltwood, C. M., M. Wong, and P. M. Shah. Quantitative echocardiography of the mitral complex in dilated cardiomyopathy: The mechanism of functional mitral regurgitation. Circulation68:498–508, 1983.PubMedGoogle Scholar
  4. 4.
    Flachskampf, F. A., S. Chandra, A. Gaddipatti, R. A. Levine, A. E. Weyman, W. Amelig, P. Hanrath, and J. D. Thomas. Analysis of shape and motion of the mitral annulus in subjects with and without cardiomyopathy by echocardiographic three-dimensional reconstruction. Am. Soc. Echocardiogr. 13:277–287, 2000.Google Scholar
  5. 5.
    Friederg, C. K. Diseases of the Heart, 2nd ed. Philadelphia, PA: Saunders, 1956, 640 pp.Google Scholar
  6. 6.
    Glasson, J. R., M. Komeda, G. T. Daughters, A. F. Bolger, A. MacIsaac, S. N. Oesterle, N. B. Ingels, and D. C. Miller. Three-dimensional dynamics of the canine mitral annulus during ischemic mitral regurgitation. Ann. Thorac. Surg. 62:1059–68, 1996.Google Scholar
  7. 7.
    Glasson, J. R., M. Komeda, G. T. Daughters, M. A. Niczyporuk, A. F. Bolger, N. B. Ingels, and D. C. Miller. Three-dimensional regional dynamics of the mitral annulus during left ventricular ejection. J. Thorac. Cardiovasc. Surg. 111:574–585, 1996.Google Scholar
  8. 8.
    Gorman, III, J. H., R. C. Gorman, B. M. Jackson, Y. Hiramatsu, N. Gikakis, S. T. Kelley, M. G. Sutton, T. Plappert, and L. H. Edmunds. Distortions of the mitral valve in acute ischemic mitral regurgitation. Ann. Thorac. Surg. 64:1026–1031, 1997.Google Scholar
  9. 9.
    Gorman, III, J. H., B. G. Krishanu, J. T. Streicher, R. C. Gorman, B. M. Jackson, M. B. Ratcliffe, D. K. Bogen, and L. H. Edmunds. Dynamic three-dimensional imaging of the mitral valve and left ventricle by rapid sonomicrometry array localization. J. Thorac. Cardiovasc. Surg. 112:712–26, 1996.Google Scholar
  10. 10.
    Gorman, III, J. H., B. M. Jackson, R. C. Gorman, S. T. Kelly, N. Gikakis, and L. H. Edmunds. Papillary muscle discoordination rather than increased annular area facilitates mitral regurgitation after acute posterior myocardial infaction. Circulation96(II):124–127, 1997.Google Scholar
  11. 11.
    He, S., J. D. Lemmon, M. W. Weston, M. O. Jensen, R. A. Levine, and A. P. Yoganathan. Mitral valve compensation for annular dilation: study into the mechanisms of functional mitral regurgitation with an adjustable annulus model. J. Heart Valve Dis. 8:294–302, 1999.Google Scholar
  12. 12.
    Kaplan, S. R., G. Bashein, F. H. Sheehan, M. E. Legget, B. Munt, X. Ning Li, M. Sirvarajan, E. L. Bolson, M. Zeppa, and R. W. Martin. Three-dimensional echocardiographic assessment of annular shape changes in the normal and regurgitant mitral valve. Am. Heart J. 139:243–250, 2000.Google Scholar
  13. 13.
    Levine, R. A., M. O. Triulizi, P. Harrigan, and A. E. Weyman. The relationship of the mitral annular shape to the diagnosis of mitral valve prolapse. Circulation75(IV):756–767, 1987.Google Scholar
  14. 14.
    Lomholt, M., S. L. Nielsen, S. B. Hansen, N. T. Andersen, and J. M. Hasenkam. Differential tension between secondary and primary mitral chordae in acute porcine model. J. Heart Valve Dis. 11:337–345, 2002.Google Scholar
  15. 15.
    Messas, E., J. L. Guerrero, M. D. Handschumacher, C. Conrad, C. Chow, S. Sullivan, A. P. Yoganathan, and R. A. Levine. Chordal cutting, A new therapeutic approach for ischemic mitral regurgitation. Circulation104:1958–1963, 2001.Google Scholar
  16. 16.
    Mikami, T., M. Hashimoto, T. Kudo, T. Sugawara, S. Sakamoto, and H. Yasuda. Mitral valve and its ring in hypertrophic cardiomyopathy, A mechanism creating surplus mitral leaflet involved in systolic anterior motion. Jpn. Circ. J. 52:597–602, 1998.Google Scholar
  17. 17.
    Morten, O. J., A. Fontaine, and A. P. Yoganathan. Improved quantification of the force exerted by the papillary muscle on the left ventricular wall three-dimensional force vector measurement system. Ann. Biomed. Eng. 10:111–124, 2000.Google Scholar
  18. 18.
    Nazari, S., F. Carli, C. Bnfi, A. Aluffi, Z. Mourad, P. Buniva, and G. Rescigno. Patterns of systolic stress distribution on mitral valve anterior leaflet chordal apparatus. J. Cardiovasc. Surg. 41:193–202, 2000.Google Scholar
  19. 19.
    Nielsen, S. L., H. Hygaard, A. A. Fontaine, J. M. Hasenkam, S. He, N. T. Andersen, and A. P. Yoganathan. Chordal force distribution determines systolic mitral leaflet configuration and severity of functional mitral regurgitation. J. Am. Coll. Cardiol. 33:843–53, 1999.Google Scholar
  20. 20.
    Pai, R. G., M. Tanimoto, W. Jintapakorn, J. Azevedo, N. G. Pandian, and P. M. Shah. Volume-rendered three-dimensional dynamic anatomy of the mitral annulus using transesophageal echocardiographic technique. J. Heart Valve Dis. 4:625–627, 1995.Google Scholar
  21. 21.
    Salgo, I. S., J. H. GormanIII, R. C. Gorman, B. M. Jackson, F. W. Bowen, T. Plappert, M. G. Sutton, and L. H. Edmunds. Effect of annular shape on leaflet curvature in reducing mitral leaflet stress. Circulation106:711–717, 2002.Google Scholar
  22. 22.
    Sedransk, K. L., J. G. Allen, and I. Vesely. Failure mechanics of mitral valve chordae tendineae. J. Heart Valve Dis. 11:644–650, 2002.Google Scholar
  23. 23.
    Timek, T. A., and D. C. Miller. Experimental and clinical assessment of mitral annular area and dynamics: What are we actually measuring?Ann. Thorac. Surg. 72:966–974, 2001.Google Scholar
  24. 24.
    Toumanidis, S. T., D. A. Sideris, C. M. Papamichael, and S. D. Moulopoulos. The role of mitral annulus motion in left ventricular function. Acta Cardiol. 4:331–348, 1992.Google Scholar

Copyright information

© Biomedical Engineering Society 2003

Authors and Affiliations

  • Jorge Hernan Jimenez
    • 1
  • Dennis Dam Soerensen
    • 1
  • Zhaoming He
    • 1
  • Shengqiu He
    • 1
  • Ajit P. Yoganathan
    • 1
  1. 1.Wallace H. Coulter Department of Biomedical EngineeringGeorgia Institute of Technology and Emory UniversityAtlanta

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