Surgical ventricular restoration (SVR) or ventriculoplasty of the dilated left ventricle (LV) after antero-apical myocardial infarction (MI) has been proposed as surgical treatment for congestive heart failure (CHF). Unsatisfactory results with standard linear aneurysm repair have stimulated modifications of that operation. Currently, patch aneurymorraphy (Dor procedure), infarct exclusion (no patch) and the Surgical Anterior Ventricular Restoration (SAVER; performed on akinetic infarcts) procedures are being performed. The long-term goal of this research is to use experimental and theoretical models to arrive at an optimal design for SVR of the dilated LV after antero-apical Mi. First, using conductance and micromanometer-tipped catheters, the effect of infarct exclusion, SAVER, and Acorn CorCap(TM) Cardiac Support Device (CSD) operations on LV pressure-volume and global function (Starling) relations will be measured in sheep hearts. Infarct exclusion and the Acorn CSD will be tested in the standard dyskinetic infarct model. The SAVER operation will be tested in the reperfused (akinetic) sheep infarct model. Next, using magnetic resonance imaging (MRI) with tissue tags, the effect of infarct exclusion, SAVER, and Acorn CSD on regional 3D myocardial strain will be measured in vivo. Then, using MR diffusion tensor imaging (MR-DTI), the effect of infarct exclusion, SAVER, and Acorn CSD operations on regional 3D myocyte orientation will be measured ex vivo. Next, realistic mathematical (finite element) models of each of the proposed SVR operations will be developed. These models will be used in conjunction with the regional 3D myocardial strain measurements to: (1) determine in vivo diastolic and systolic myocardial material properties in the beating sheep LV with either a complete transmural (dyskinetic) or reperfused (akinetic) infarct; and (2) calculate regional 3D myocardial stress and global LV function. Finally, the design of infarct exclusion, SAVER, and Acorn CSD operations will be optimized using these models. Specifically, the effect of residual contracting myocytes (dyskinetic vs akinetic infarct; infarct exclusion and SAVER), the amount of excluded or resected myocardium (infarct exclusion and SAVER), patch stiffness and location (endocardium vs. epicardium; SAVER) and the compliance of the Acorn CSD will be simulated. This study will determine the acute and sub-acute effects of infarct exclusion, SAVER and Acorn CSD procedures on the dilated LV after antero-apical MI. These findings should have a major impact on current surgical practice.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL063348-08
Application #
7237282
Study Section
Surgery and Bioengineering Study Section (SB)
Program Officer
Miller, Marissa A
Project Start
2000-04-17
Project End
2009-05-31
Budget Start
2007-06-01
Budget End
2008-05-31
Support Year
8
Fiscal Year
2007
Total Cost
$312,899
Indirect Cost
Name
Northern California Institute Research & Education
Department
Type
DUNS #
613338789
City
San Francisco
State
CA
Country
United States
Zip Code
94121
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Pantoja, Joe Luis; Morgan, Ashley E; Grossi, Eugene A et al. (2017) Undersized Mitral Annuloplasty Increases Strain in the Proximal Lateral Left Ventricular Wall. Ann Thorac Surg 103:820-827
Morgan, Ashley E; Wozniak, Curtis J; Gulati, Sarthak et al. (2017) Association of Uneven MitraClip Application and Leaflet Stress in a Finite Element Model. JAMA Surg 152:111-114
Morgan, Ashley E; Pantoja, Joe L; Grossi, Eugene A et al. (2016) Neochord placement versus triangular resection in mitral valve repair: A finite element model. J Surg Res 206:98-105
Ge, Liang; Wu, Yife; Soleimani, Mehrdad et al. (2016) Moderate Ischemic Mitral Regurgitation After Posterolateral Myocardial Infarction in Sheep Alters Left Ventricular Shear but Not Normal Strain in the Infarct and Infarct Borderzone. Ann Thorac Surg 101:1691-9
Ge, Liang; Haraldsson, Henrik; Hope, Michael D et al. (2016) Suture Forces for Closure of Transapical Transcatheter Aortic Valve Replacement: A Mathematical Model. J Heart Valve Dis 25:424-429
Ge, Liang (2016) A Characteristic-Based Constitutive Law for Dispersed Fibers. J Biomech Eng 138:
Morgan, Ashley E; Pantoja, Joe Luis; Weinsaft, Jonathan et al. (2016) Finite Element Modeling of Mitral Valve Repair. J Biomech Eng 138:021009
Ratcliffe, Mark; Cambronero, Neil; Takaba, Kiyoaki et al. (2015) Studies on postinfarct left ventricular remodeling: state of the art. Ann Thorac Surg 99:755-6
Yaffee, David W; Grossi, Eugene A; Ratcliffe, Mark B (2015) Progressive design concepts in off-pump left ventricular remodeling mitral valve repair devices. Ann Cardiothorac Surg 4:352-4

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