The six primary areas supplied by the major coronary arteries:
The GUSTO study enrolled patients with ST segment elevation in two contiguous leads and defined four affected areas as follows:

Area of ST segment elevation	Leads defining this area
Anterior	V1-4
Apical	V5-6
Lateral	I, aVL
Inferior	II, III, aVF

Additional primary areas not included in the GUSTO study:
Two other major areas of possible injury or infarction were not included in the GUSTO categorization above, because they do not produce ST elevation in two contiguous standard leads. These were:

1. Posterior: The most commonly used sign of posterior injury is ST depression in leads V1-3, but posterior injury may best be diagnosed by obtaining posterior leads V7, V8 and V9.
2. Right ventricle: The most sensitive sign of RV injury, ST segment elevation > 1 mm, is found in lead V4R. A very specific, but insensitive, sign of RV injury and/or infarction is ST elevation in V1, with concomitant ST segment depression in V2 in the setting of ST elevation in the inferior leads. This reflects the confounding effects of RV injury on lead V t in a person with posterior injury.

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