The South African Flag Sign-An Electrocardiographic Sign to Predict the Culprit Artery

QJM. 2021 May 14;hcab137. doi: 10.1093/qjmed/hcab137. Online ahead of print.


We report a case of acute high lateral wall myocardial infarction with ST-segment elevation in leads I, aVL, and V2 with reciprocal ST-segment depression in the lead III. This pattern of ST-segment elevation and depression is called the South African flag sign as it occupies the middle green strip of the South African flag. This classic sign can help us localize the culprit artery, which is usually the first diagonal branch (D1) of the left anterior descending artery (LAD).