Spatial proximity or vector orientation? Re-evaluating ECG interpretation in anterior myocardial infarction using...

Area of Science:

• Cardiology
• Medical Imaging
• Electrocardiography

Background:

• Electrocardiogram (ECG) is standard for assessing anterior myocardial infarction (MI) location and extent.
• Traditional ECG methods rely on lead proximity or ST-segment deviation vectors.
• The accuracy of ECG in determining infarct characteristics against direct imaging is not well-established.

Purpose of the Study:

• To evaluate the accuracy of conventional and simplified ECG methods in localizing myocardial injury.
• To compare ECG findings with cardiac magnetic resonance (CMR) imaging in anterior MI patients.
• To determine if ECG can reliably assess infarct size and location.

Main Methods:

• Prospective study of 105 anterior MI patients.
• Cardiac magnetic resonance (CMR) imaging performed 3-7 days post-presentation.
• ECG analysis included conventional localization and simplified ST-axis orientation; CMR assessed infarct distribution via late gadolinium enhancement and edema imaging.

Main Results:

• Conventional ECG localization categories showed no significant association with CMR-defined infarct distribution (P=0.24), with poor agreement (κ=0.122).
• Simplified ST-axis orientation had modest, inconsistent associations with infarct location and size.
• Global ST-segment burden (ΣSTE and lead count) showed a modest association with CMR-defined infarct size (P=0.002 and P=0.007, respectively).

Conclusions:

• Conventional ECG localization and simplified ST-axis orientation poorly correlated with CMR-defined infarct distribution in anterior STEMI patients.
• Global ST-segment burden demonstrated a modest association with infarct size.
• ECG may be more effective in reflecting myocardial injury extent rather than precise anatomical location in this cohort.