746-3 Impaired Wall Thickening of Adjacent Non-Infarcted Myocardium is Associated with Regional Myocyte Hypertrophy and Dysfunction During Post-Infarct Remodeling

Clicks: 195
ID: 272348
1995
Article Quality & Performance Metrics
Overall Quality Improving Quality
0.0 /100
Combines engagement data with AI-assessed academic quality
AI Quality Assessment
Not analyzed
Abstract
Wall thickening (WT) is impaired in non-infarcted regions adjacent to Myocardial Infarction (MI) and is thought to be caused by mechanical overload and geometric chamber distortion. The contribution of abnormalities intrinsic to the myocyte to impaired WT during remodeling has not been examined. To correlate local WT in vivo with myocyte morphology and function during LV remodeling, magnetic resonance imaging (MRI) was performed 2 weeks after MI (left coronary artery ligation) by obtaining EKG-gated spin-echo shortaxis images (1.5 Tesla, 3 inch coil). Myocytes were isolated from 14 rats with MI and 4 shams. Local WT in regions adjacent (A) and remote (R) to the infarct scar visible by MRI was correlated with cell morphology and function, studied in myocytes isolated from A and R. MI size measured by planimetry ranged from 5% to 30% (mean 18.7%) of the outer LV area. Regional differences in local WT were present in MI hearts: average %WT in A was lower than in R (27.8 ± 6.14 (sem) vs 54.0 ± 10.17: p < 0.01). In rats with large MI (MI > 20%, n = 7). cells were longer than in sham (p < 0.05: n = 175) both in R(143.1 ± 1.76 vs 120.9 ± 2.40 μm) and in A (150.3 ± 1.89 vs 122.6 ± 2.02 μm) while no changes were evidenced in cell width. Cells from A were longer than those from R(p < 0.05). A positive correlation between MI size and cell length was found (for A: r = 0.8, slope 0.07). Electrically-stimulated cell contraction (see figure, %ES: cell shortening / diastolic length: values aTe mean ± sem), was impaired in A with respect to sham (**: p < 0.05) and to R (*: p = 0.06). Thus, during post-MI remodeling, dysfunction in A non-infarcted regions is associated with greater myocyte elongation and dysfunction than in R. In conclusion, local myocyte dysfunction contributes to WT impairment in adjacent regions after MI.
Reference Key
silverman1995journal746-3 Use this key to autocite in the manuscript while using SciMatic Manuscript Manager or Thesis Manager
Authors Guido Melillo,João A.C. Lima,Robert M. Judd,Howard S. Silverman;Guido Melillo;João A.C. Lima;Robert M. Judd;Howard S. Silverman;
Journal Journal of the American College of Cardiology
Year 1995
DOI
10.1016/0735-1097(95)92244-y
URL
Keywords

Citations

No citations found. To add a citation, contact the admin at info@scimatic.org

No comments yet. Be the first to comment on this article.