A 66-year-old man was attending a play in a downtown theater when he developed severe anterior chest pain. His wife accompanied him to the emergency department of a nearby hospital, where this ECG is recorded 25 minutes after onset of his symptoms:

• Sinus rhythm, 69/min
• ST elevation with tall positive T waves in V2-V5 (hyperacute T waves)
• Acute anterior myocardial infarction

The patient was taken to cardiac catheterization laboratory. Coronary angiography demonstrated a total occlusion in the mid-segment of the left anterior coronary artery. Thrombectomy was successfully carried out and a bare metal stent was inserted. This ECG is recorded when the patient was admitted to the CCU after the procedure:

• Sinus rhythm, 66/min
• QRS changes of septal infarction

Compared with ECG 1, in V1-V3 the ST elevation and T wave voltage have markedly decreased.

This ECG is recorded 24 hours after ECG 2. The condition of the patient is stable and very satisfactory:

• Sinus rhythm, 63/min
• Septal myocardial infarction.
• 1 mm ST elevation in V1-V3, negative T waves in V1-V6