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Updated: Jul 9, 2026
Primary Outcome Assessment in a Pig Model of Acute Myocardial Infarction
Published on: October 14, 2016
Time course of echocardiographic and electrocardiographic parameters in myocardial infarct in rats
Amarildo Miranda1, Ricardo H Costa-e-Sousa, João P S Werneck-de-Castro
1Laboratório de Eletrofisiologia Cardíaca, CCS-UFRJ, Rio de Janeiro, RJ, Brazil.
Insights
Estimating myocardial infarct size in rats using electrocardiograms (ECG) and echocardiograms (ECHO) is challenging. This study found that ECHO at 7 days post-infarction provides the most accurate estimation of infarct size.
Area of Science:
- Cardiovascular Research
- Animal Models of Cardiac Disease
- Diagnostic Imaging in Cardiology
Background:
- Accurate in vivo assessment of myocardial infarct size in animal models remains a significant challenge.
- Relating in vivo measurements to post-mortem histopathology is crucial for validating diagnostic methods.
Purpose of the Study:
- To determine if conventional electrocardiography (ECG) and echocardiography (ECHO) can reliably predict myocardial infarct size in rats.
- To evaluate the accuracy of ECG and ECHO at different time points post-infarction.
Main Methods:
- Wistar rats underwent left coronary artery ligation to induce myocardial infarction.
- Electrocardiography (ECG), echocardiography (ECHO), and histopathology were performed at 1, 7, and 28 days post-surgery.
- Correlation analyses were conducted between imaging modalities and histological infarct size.
Main Results:
- Electrocardiography (ECG) showed correlation with infarct size only at 1 day post-surgery (Q wave amplitude in lead L1).
- Echocardiography (ECHO) parameters, including left ventricular dimensions and ejection indexes, correlated with infarct size at 7 and 28 days post-infarction.
- The 7-day post-infarction interval demonstrated the highest accuracy for infarct size estimation using echocardiography (ECHO).
Conclusions:
- Conventional ECG and ECHO methods are viable tools for estimating myocardial infarct size in rat models.
- Echocardiography (ECHO) at 7 days post-infarction offers the most accurate non-invasive assessment of infarct size in this model.
- These findings support the use of specific imaging time points for reliable infarct size evaluation in preclinical cardiovascular research.
Abstract:
In animal models the evaluation of myocardial infarct size in vivo and its relation to the actual lesion found post mortem is still a challenge. The purpose of the current study was to address if the conventional electrocardiogram (ECG) and/or echocardiogram (ECHO) could be used to adequately predict the size of the infarct in rats. Wistar rats were infarcted by left coronary ligation and then ECG, ECHO and histopathology were performed at 1, 7 and 28 days after surgery. Correlation between infarct size by histology and Q wave amplitude in lead L1 was only found when ECGs were performed one day post-surgery. Left ventricular diastolic and systolic dimensions correlated with infarct size by ECHO on day 7 post-infarction. On days 7 and 28 post-infarction, ejection indexes estimated by M-mode also correlated with infarct size. In summary we show that conventional ECG and ECHO methods can be used to estimate infarct size in rats. Our data suggest that the 7-day interval is actually the most accurate for estimation of infarct size by ECHO.
