Rare Electrocardiographic Patterns of Occlusive Coronary Artery Disease In The Absence of ST Segment Elevation

Acute coronary syndrome is traditionally classified based on the presence of ST-segment elevation, which is considered a marker of acute coronary artery occlusion. This established paradigm, however, does not always reflect the pathophysiological reality. Current data show that up to 34% of patients with non-ST-segment elevation myocardial infarction have total occlusion of the infarction-related artery, which is associated with an increased risk of mortality. This emphasizes that the absence of ST-segment elevation does not exclude the presence of an occlusive lesion. In addition to the well-known electrocardiographic equivalents of ST-segment elevation myocardial infarction, numerous rare and subtle patterns have been described in the literature that suggest acute coronary occlusion. To systematize these data, a literature review was conducted. It revealed that rare electrocardiographic phenomena such as hyperacute T waves, terminal QRS distortion, precordial swirl, Aslanger patterns, and northern myocardial infarction patterns may potentially have high diagnostic value. The analysis demonstrates that in most cases, the presence of these patterns is highly specific for occlusion and is associated with more extensive myocardial damage and a worse prognosis. However, their widespread adoption in routine practice is limited by low sensitivity and the complexity of visual assessment, which requires specialized training and the use of automated electrocardiogram analysis systems. These issues necessitate further prospective studies to confirm the clinical significance of these patterns and the development of artificial intelligence algorithms for their accurate interpretation in clinical practice.