Longitudinal Study of Cardiac Remodelling in Rabbits Following Infarction

Yves T. Wang, Zoran B. Popović, Igor R. Efimov, Yuanna Cheng*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

Background: Cardiac remodelling following myocardial infarction (MI) is a complex, dynamic process. There have been few longitudinal studies of these changes. Methods: A 2-dimensional transthoracic echocardiography was performed on 20 rabbits, before and 1, 2, 4, 8, and 12 weeks after MI (n = 14) and twice for controls (n = 6). Chronic left ventricular (LV) infarct size was histologically characterized and correlated with mechanical function. A linear mixed model was used to analyze longitudinal and infarct size-related changes in LV end-systolic volume (ESV), end-diastolic volume (EDV), ejection fraction (EF), sphericity, circumferential strain, and wall motion score index. Results: Mean LV infarct size was 28.9% ± 9.3%. After MI, rapid remodelling occurred in LVESV, LVEF, and sphericity for 2 weeks and LVEDV for 4 weeks, with slower changes afterwards. LV infarct size correlated with LVESV (r = 0.76), LVEDV (r = 0.71), and LVEF (r = 0.69). Larger infarcts resulted in greater LVESV dilation (P = 0.04) and faster LVEDV (P < 0.01), LVEF (P < 0.01), and sphericity (P < 0.01) remodelling. Apical global circumferential strain and wall motion score index increased for 1 week, then stabilized, regardless of infarct size, and apical global circumferential strain was correlated with apical infarction (r = 0.58). Additionally, regional circumferential strain decreased in segments with severe (> 80%) infarction more quickly (P < 0.01) and by a greater degree (P = 0.04) compared with segments with minor (< 20%) infarction. Conclusions: The most dynamic remodelling of cardiac function in this model occurred during the first 4 weeks, stabilizing thereafter, with changes maintained up to 12 weeks. Infarct size affected both the early rate and long-term extent of mechanical remodelling.

Original languageEnglish (US)
Pages (from-to)230-238
Number of pages9
JournalCanadian Journal of Cardiology
Volume28
Issue number2
DOIs
StatePublished - Mar 2012
Externally publishedYes

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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