This 63-year-old man had been well and very active until 6 weeks ago, when he started experiencing occasional episodes of anterior chest pain during exertion,  relieved by rest. About 10 days later he awoke with severe pain across his anterior chest, that lasted one hour.  The  ECG abnormalities shown in this tracing were discovered two weeks ago and have remained unchanged since. The patient has been referred for investigation, because of persistent angina on exertion:

• Sinus bradycardia, 58/min
• R>S in V2 and ST elevation with tall T waves in V1-V4, unchanged since previous tracing of 2 weeks ago. Consider posterior myocardial infarction
• Negative T waves in I, aVL, V5 and V6, consider lateral ischemia

Comments: The marked ST elevation and tall T waves (resembling “hyperacute T waves”) in the precordial leads mimic the changes of acute septal infarction. The persistence of these abnormalities, however, and the presence of tall R waves in V2 (R/S ratio > 1), favor the diagnosis of posterior infarction. Coronary angiography demonstrated severe proximal occlusion a large circumflex artery that was successfully treated with angioplasty and stenting.