- Poster presentation
- Open Access
Real time MRI of border zone end-systolic regional work
© Contijoch et al; licensee BioMed Central Ltd. 2013
- Published: 30 January 2013
- Stroke Work
- Inflow Occlusion
- Magnetic Resonance Imaging Method
- Dobutamine Stress Test
Heart failure results in 280,000 deaths each year in the US and post-myocardial infarction (MI) remodeling is among the leading causes. An unresolved question is the integrity of the molecular contractile apparatus in the peri-infarct or borderzone (BZ) myocardium and the resulting effect on infarct stretching and thinning and BZ expansion. A difficulty is the lack of available methods to noninvasively measure the BZ stress-strain relation under varying loading conditions in vivo. Our hypothesis is that the BZ myocardium has significantly reduced end-systolic stiffness as measured by MRI-derived regional preload recruitable stroke work (rPRSW). To test this hypothesis, we transiently varied loading conditions in post-infarct swine and measured real time LV apparent fiber length using nonlinear image reconstruction and sub-Nyquist golden angle MRI.
Yorkshire male swine (N=3, mean weight = 60 kg) were used in an IACUC approved posterobasal MI study. At 1 week post-MI, a hydraulic balloon catheter device was positioned in the IVC. Real time golden angle radial bSSFP MRI synchronized with LV pressure during IVC occlusion (N=2) and dobutamine stress test (N=1) was performed. Images were reconstructed using Gadgetron framework (Hansen, 2012) using an iterative SENSE-based algorithm (Pruessmann, 1999) with k-space weighted imaging contrast (KWIC) temporal filtering (Song, 2000). The ventricular cavity and myocardium was segmented using a level-set algorithm (Yushkevich, 2006) and endocardial and epicardial points wall thickness (WT) was tracked using a non-rigid intensity based algorithm (Rueckert, 1999) from wall contours throughout inflow occlusion. rPRSW was quantified by the area of the Pressure- Relative Fiber Length loop.
Regional variations in local work performed were observed during transient preload reduction using a real time magnetic resonance imaging method. These findings provide insight about load-dependent changes in contractile function in post-infarction LV remodeling.
R01-HL103723, R01-HL63954, R01-HL73021, and T32-EB009384.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.