Anterior Myocardial Infarction

An anterior myocardial infarction results from occlusion of the left anterior descending coronary artery.

This can cause an ST elevation myocardial infarction or a non-ST segment elevation myocardial infarction. The mechanism is usually plaque rupture causing thrombus; however, plaque erosion or progressive hemodynamic stenosis can contribute as well.

When an anterior myocardial infarction extends to the septal and lateral regions as well, the culprit lesion is usually more proximal in the left anterior descending coronary artery (LAD) or even in the left main coronary artery. This large myocardial infarction is termed an "extensive anterior."

The ECG findings of an anterior ST segment elevation myocardial infarction include:

1. ST segment elevation in the anterior leads (V3 and V4) and sometimes in septal and lateral leads, depending on the extent of the infarction. This ST elevation is concave downward and frequently overwhelms the T wave, producing a "tombstone" appearance.

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      2. Reciprocal ST segment depression in the inferior leads (II, III and aVF).

The ECG findings of an old anterior myocardial infarction include:

1. Loss of anterior forces leaving Q waves in leads V1 and V2. This is sometimes termed "poor R wave progression" or PRWP. Note: To distinctly say that an old anterior wall MI is present on the ECG, there must be no identifiable R wave in lead V1 and usually V2 as well. If there is an R wave in V1 or V2, the term PRWP can be used, but not an old anterior wall myocardial infarction.
2. On rare occasions, persistent ST elevation may be seen in V1 and/or V2 indicating a ventricular aneurysm.

Anterior MI ECG - STEMI (Example 1)
Anterior MI ECG - STEMI (Example 2)
Anterior MI ECG - STEMI (Example 3)
Anterior MI ECG - STEMI (Example 4)
Anterior MI ECG - STEMI (Example 5)
Anterior MI ECG - STEMI (Example 6)
Anterior Wall ST elevation MI with RBBB (Example)
Old Anterior Wall MI (Example)