Abnormal repolarization in the acute myocardial infarction patients: a frequency-based characterization

Area of Science:

• Cardiology
• Biomedical Engineering
• Signal Processing

Background:

• ST elevation on electrocardiograms (ECG) has limited sensitivity for diagnosing acute myocardial infarction (AMI).
• There is a need for improved ECG-based diagnostic tools for AMI.
• Repolarization abnormalities are key indicators in ECG analysis for cardiac conditions.

Purpose of the Study:

• To introduce and evaluate a novel f99 index for discriminating between acute myocardial infarction (AMI) and healthy individuals using ECG data.
• To assess the sensitivity and specificity of the f99 index in AMI detection.
• To investigate the lead dependency of the f99 index in ECG recordings.

Main Methods:

• The study analyzed 12-lead ECG recordings from 47 healthy controls and 108 AMI patients.
• A new index, f99 (frequency at 99% normalized cumulative repolarization energy), was calculated.
• The f99 index was evaluated for its discriminatory power, sensitivity (Se), and specificity (Sp) across different ECG leads and lead systems.

Main Results:

• The f99 index demonstrated significant differences between healthy controls and AMI patients, with higher median f99 values observed in AMI patients across most leads (12-38 Hz vs. 10-17 Hz).
• Lead dependency was noted, with optimal single-lead discrimination achieved in leads I (Se=80%, Sp=77%) and aVl (Se=84%, Sp=74%).
• A lead-system analysis, averaging the 6 precordial leads, yielded high discrimination (Se=81%, Sp=74%).

Conclusions:

• The novel f99 index is a promising, non-invasive tool for reliably discriminating between acute myocardial infarction (AMI) and healthy subjects.
• The f99 index provides a sensitive and specific measure of repolarization abnormalities indicative of AMI.
• Further validation of the f99 index in larger cohorts is warranted for clinical application in AMI diagnosis.