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Intermittent pacing therapy favorably modulates infarct remodeling
André Uitterdijk1, Tirza Springeling1,2, Kevin C M Hermans3
1Department of Cardiology, Ee-2351, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000 CA, Rotterdam, The Netherlands.
Basic Research in Cardiology
|April 8, 2017
Summary
Intermittent pacing therapy (IPT) after acute myocardial infarction (AMI) did not alter overall left ventricular remodeling but improved infarct healing by increasing myofibroblast content in the infarct zone.
Area of Science:
- Cardiology
- Regenerative Medicine
- Biomedical Engineering
Background:
- Left ventricular (LV) remodeling and dysfunction post-acute myocardial infarction (AMI) are significant therapeutic challenges despite early revascularization.
- Intermittent pacing therapy (IPT) applied during early reperfusion may limit infarct size.
- The impact of IPT on post-AMI LV remodeling and infarct healing remains largely unexplored.
Purpose of the Study:
- To investigate the effects of IPT on global LV remodeling and infarct geometry in a swine model of subacute AMI.
- To assess the influence of IPT on infarct healing, myofibroblast content, extracellular matrix (ECM) turnover, and Wnt/frizzled signaling.
Main Methods:
- Swine model with a 3-day-old AMI induced by coronary artery ligation and reperfusion.
- Epicardial pacing lead implantation in the peri-infarct zone for IPT.
- Magnetic resonance imaging (MRI) for assessment of LV remodeling and infarct geometry at baseline and 35 days post-AMI.
- Histological and molecular analysis of infarct and non-infarct tissues for myofibroblast content and gene expression.
Main Results:
- IPT did not significantly affect global LV remodeling, function, or infarct mass.
- IPT modulated infarct healing, primarily by reducing the number of infarct segments rather than infarct thickness.
- Myofibroblast content in the infarct zone was significantly higher in the IPT group compared to the MI control group.
- No significant alterations in ECM turnover or Wnt/frizzled signaling were observed at 5 weeks post-AMI.
Conclusions:
- Intermittent pacing therapy influences infarct healing and composition in subacute myocardial infarction.
- IPT appears to limit infarct expansion and alter infarct characteristics, potentially through increased regional myofibroblast content.
- Further research is warranted to elucidate the precise mechanisms and long-term clinical implications of IPT in myocardial infarction recovery.