Myocardial infarction due to left main coronary artery total occlusion: A unique electrocardiographic presentation

Area of Science:

• Cardiology
• Electrocardiography
• Internal Medicine

Background:

• Left main coronary artery (LMCA) total occlusion classically presents with specific electrocardiogram (ECG) findings, often anterolateral ST-segment myocardial infarction.
• These typical findings may include right bundle branch block, left anterior fascicular block, and ST-segment elevation in lead aVR.

Purpose of the Study:

• To describe a distinct and atypical electrocardiographic presentation of total left main coronary artery (LMCA) occlusion.
• To highlight the de Winter's sign as a potential indicator of LMCA occlusion.

Main Methods:

• Case report detailing a patient with total LMCA occlusion.
• Analysis of the patient's electrocardiogram (ECG) findings.

Main Results:

• The patient presented with a complete left bundle branch block (LBBB).
• Atypical ECG findings included upsloping ST-segment depression in precordial leads.
• Symmetrical, tall, positive T waves, consistent with de Winter's sign, were observed.

Conclusions:

• Total LMCA occlusion can manifest with an electrocardiographic pattern different from the classic presentation.
• The presence of complete LBBB combined with de Winter's sign may indicate total LMCA occlusion and warrants urgent investigation.