Wellen's syndrome is an ECG pattern that is associated with a high risk for anterior wall infarction from large stenosis of the LAD. T wave inversion and a biphasic pattern is seen in leads V2 and V3 (may occur in V1-6), minimal ST elevation and absence of Q waves.
Often the patient has a history of angina but may have no chest pain at the time of ECG.
In terms of management, patients often require PCI given the high risk of extensive LAD stenosis causing large infarct and the T wave changes are similar to patients who have had successful reperfusion from PCI for an anterior MI.