The pattern of clinical findings and electrocardiography (ECG) changes known as 
Wellens' syndrome is associated with significant stenosis of the proximal left 
anterior descending coronary artery. Cases can be classified according to the 
ECG pattern into type 1 (biphasic T waves) or type 2 (deeply inverted T waves, 
especially in leads V2 and V3). We present here an unusual case of Wellens' 
syndrome in which the ECG pattern changed from type 2 to type 1 during 
observation, and in which the coronary lesion was in the middle rather than the 
proximal part of the left anterior descending artery.