Acute ischemia induces dynamic changes across multiple ECG markers beyond the ST segment, where repolarization changes precede and exceed depolarization; these responses are modulated by age and sex, and prior infarction tightens their correlation with ischemic burden and alters spatial lead patterns.
Multiple ECG markers beyond ST-segment deviation evolve over time during coronary artery occlusion.
Repolarization features changed earlier and more strongly than depolarization features during occlusion.
Sex modulated the ST-segment response to ischemia, with males showing faster and more sustained increases.
Age modulated the temporal pattern of the ST response.
In patients with a prior infarction, ECG changes correlated more strongly with the extent and severity of ischemia.
Distinct spatial lead patterns of ECG changes were identified depending on the occluded artery and the presence of a prior infarction.
A prior infarction modifies the myocardial ECG response to a new acute ischemic event.
This study looked at electrocardiograms (ECGs) recorded before and during short, controlled blockages of a major heart artery in patients undergoing a procedure called percutaneous coronary intervention. Doctors usually rely on changes in the ST segment of the ECG to detect a heart attack or ischemia, but the researchers tracked many other features of the heartbeat over time, including QRS width and T-wave measures. They found that many features besides the ST segment change during artery blockage. Changes in the repolarization phase (the heart's electrical recovery, including the ST segment and T wave) appeared earlier and were larger than changes in depolarization (the QRS). By 4 minutes of blockage, repolarization measures had changed about 37-fold and depolarization measures about 23-fold. Males showed faster, larger ST increases than females, and older patients showed a sharp early ST peak while younger patients had a more gradual rise. In patients who had a previous heart attack, ECG changes tracked more closely with how extensive and severe the ischemia was, and the pattern across ECG leads differed depending on which artery was blocked. This research suggests that taking age, sex, prior heart attack history, and a wider range of ECG markers into account could help refine ECG-based assessment of acute ischemia, though the study does not by itself show how this would change clinical care.
Rodríguez-Carbó J, Mincholé A, Pueyo E. (2026). Characterizing acute ischemia via ECG: A study of severity, extent, and spatial variability in myocardial infarction and non-infarction groups.. PloS one. https://doi.org/10.1371/journal.pone.0361220