Riding the wave: a quantitative report of electrocardiogram utilization for myocardial infarction confirmation

Area of Science:

• Cardiovascular Physiology
• Surgical Research
• Biomedical Engineering

Background:

• Confirming surgical success in myocardial infarction (MI) models is crucial for research reproducibility.
• Current methods for assessing surgical outcomes in coronary artery ligation models can be time-consuming and less precise.
• Quantitative electrocardiogram (ECG) analysis offers a potential real-time feedback mechanism.

Purpose of the Study:

• To develop and validate a quantitative ECG profile for confirming the success of permanent coronary artery ligation in mice.
• To identify specific ECG parameters that correlate with infarct size and surgical outcomes.
• To assess the utility of ECG measurements for real-time feedback during MI surgeries.

Main Methods:

• Electrocardiograms (ECGs) were recorded at baseline and at 0, 1, and 5 minutes after coronary artery ligation in two cohorts of mice (C57Bl6/J and CD8-/-).
• ECG data, including QRS complex and R-S amplitude, were analyzed using LabScribe software.
• Receiver operating characteristic (ROC) curve analysis was employed to determine the sensitivity and specificity of ECG parameters in predicting infarct size (≥35% by TTC staining).

Main Results:

• The QRS complex, but not R-S amplitude, showed significant changes after ligation and was significantly different between mice with infarcts ≥35% versus <35% at 1 minute post-ligation.
• ROC analysis indicated that changes in the QRS complex at 1 and 5 minutes post-ligation strongly correlated with surgical success (infarct size ≥35%).
• The non-normalized QRS complex at 1 minute post-ligation achieved an 86% success rate in predicting infarct size in the validation cohort.

Conclusions:

• Quantitative ECG analysis, specifically the area under the QRS complex 1 minute after ligation, provides a reliable and reproducible method for confirming surgical success in MI models.
• This real-time ECG feedback can decrease experimental time and reduce animal usage by improving surgical outcome assessment.
• The developed method is independent of sex and genotype, enhancing its applicability in diverse research settings.