The specific aim of this project is to characterize the etiology and pathogenesis of progressive post infarction mitral insufficiency. Through this characterization, the following hypothesis will be tested: The left ventricle undergoes global remodeling following posterior wall myocardial infarction. This remodeling occurs in a distinct pattern and is a result of alteration in regional wall stresses which results in progressive post infarction mitral insufficiency. A recently described large animal model of progressive ischemic mitral insufficiency will be used to collect serial sets of data. An array of 37 miniature radiopaque markers will be placed throughout the left ventricle, mitral annulus, leaflets, and papillary muscles. The simultaneous 3-D location of these markers will then be followed throughout all phases of the cardiac cycle using high-speed, biplane radiographic images each 16.7 msec. Data will be collected four times over a twelve week period permitting the evaluation and tracking of changes in all components of the mitral valve as post infarction mitral insufficiency develops. Histologic analysis of the remodeling left ventricle will also be performed to correlate ultrastructural evolution with changes in the biomechanical environment. This novel approach of evaluating both biomechanical and ultrastructural changes may be necessary to definitively elucidate the basic cardiovascular mechanism of this perplexing clinical problem.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32HL009569-02
Application #
2445072
Study Section
Surgery and Bioengineering Study Section (SB)
Project Start
1997-07-01
Project End
Budget Start
1997-07-01
Budget End
1998-06-30
Support Year
2
Fiscal Year
1997
Total Cost
Indirect Cost
Name
Stanford University
Department
Surgery
Type
Schools of Medicine
DUNS #
800771545
City
Stanford
State
CA
Country
United States
Zip Code
94305
Tibayan, Frederick A; Wilson, Ariane; Lai, David T M et al. (2007) Tenting volume: three-dimensional assessment of geometric perturbations in functional mitral regurgitation and implications for surgical repair. J Heart Valve Dis 16:1-7
Rodriguez, Filiberto; Green, G Randall; Dagum, Paul et al. (2006) Left ventricular volume shifts and aortic root expansion during isovolumic contraction. J Heart Valve Dis 15:465-73
Tibayan, Frederick A; Lai, David T M; Timek, Tomasz A et al. (2003) Alterations in left ventricular curvature and principal strains in dilated cardiomyopathy with functional mitral regurgitation. J Heart Valve Dis 12:292-9
Timek, Tomasz A; Green, G Randall; Tibayan, Frederick A et al. (2003) Aorto-mitral annular dynamics. Ann Thorac Surg 76:1944-50
Nielsen, Sten Lyager; Timek, Tomasz A; Green, G Randall et al. (2003) Influence of anterior mitral leaflet second-order chordae tendineae on left ventricular systolic function. Circulation 108:486-91
Lai, David T; Timek, Tomasz A; Tibayan, Frederick A et al. (2002) The effects of mitral annuloplasty rings on mitral valve complex 3-D geometry during acute left ventricular ischemia. Eur J Cardiothorac Surg 22:808-16
Tibayan, Frederick A; Lai, David T M; Timek, Tomasz A et al. (2002) Alterations in left ventricular torsion in tachycardia-induced dilated cardiomyopathy. J Thorac Cardiovasc Surg 124:43-9
Timek, Tomasz A; Lai, David T; Tibayan, Frederick et al. (2002) Atrial contraction and mitral annular dynamics during acute left atrial and ventricular ischemia in sheep. Am J Physiol Heart Circ Physiol 283:H1929-35
Timek, Tomasz A; Lai, David T; Tibayan, Frederick A et al. (2002) Septal-lateral annular cinching ('SLAC) reduces mitral annular size without perturbing normal annular dynamics. J Heart Valve Dis 11:2-9; discussion 10
Timek, T A; Nielsen, S L; Green, G R et al. (2001) Influence of anterior mitral leaflet second-order chordae on leaflet dynamics and valve competence. Ann Thorac Surg 72:535-40; discussion 541

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