Border zone geometry increases wall stress after myocardial infarction: contrast echocardiographic assessment.
Publication/Presentation Date
2-1-2003
Abstract
After myocardial infarction (MI), the border zone expands chronically, causing ventricular dilatation and congestive heart failure (CHF). In an ovine model (n = 4) of anteroapical MI that results in CHF, contrast echocardiography was used to image short-axis left ventricular (LV) cross sections and identify border zone myocardium before and after coronary artery ligation. In the border zone at end systole, the LV endocardial curvature (K) decreased from 0.86 +/- 0.33 cm(-1) at baseline to 0.35 +/- 0.19 cm(-1) at 1 h (P < 0.05), corresponding to a mean decrease of 55%. Also in the border zone, the wall thickness (h) decreased from 1.14 +/- 0.26 cm at baseline to 1.01 +/- 0.25 cm at 1 h (P < 0.05), corresponding to a mean decrease of 11%. By Laplace's law, wall stress is inversely proportional to the product K. h. Therefore, a 55% decrease in K results in a 122% increase in circumferential stress; a 11% decrease in h results in a 12% increase in circumferential stress. These findings indicate that after MI, geometric changes cause increased dynamic wall stress, which likely contributes to border zone expansion and remodeling.
Volume
284
Issue
2
First Page
475
Last Page
479
ISSN
0363-6135
Published In/Presented At
Jackson, B. M., Gorman, J. H., 3rd, Salgo, I. S., Moainie, S. L., Plappert, T., St John-Sutton, M., Edmunds, L. H., Jr, & Gorman, R. C. (2003). Border zone geometry increases wall stress after myocardial infarction: contrast echocardiographic assessment. American journal of physiology. Heart and circulatory physiology, 284(2), H475–H479. https://doi.org/10.1152/ajpheart.00360.2002
Disciplines
Medicine and Health Sciences
PubMedID
12414441
Department(s)
Department of Medicine, Cardiology Division
Document Type
Article