Heart Attack Types - OmniMedicalSearch.com (Myocardial Infarction)

Conditions & Diseases: Cardiovascular System

Heart Attack (Myocardial Infarction)

Types of Heart Attacks

Doctors use 3 different criteria to classify heart attacks.

I. The part of the heart that was damaged.

II. The changes seen on an electrocardiogram.

III. The anatomic (or morphologic) extent of necrosis.

I. According to the first criterion, there are two types of heart attacks:

1. Anterior infarct. Anterior infarct is the most dangerous type of heart attack and is caused by a blockage in the branch of the left coronary artery. It affects the lower chamber on the left side of the heart (left ventricle which pumps blood to all parts of the body) and damages the front part of the heart.

2. Posterior or inferior infarct. Posterior infarct is a less serious form of heart attack and is caused by a blockage in the right coronary artery or one of its branches. It affects the back or the base of the heart.

II. According to the second criterion, there are two type of heart attacks:

1. ST segment elevation myocardial infarction (STEMI). This type of heart attack is caused by a prolonged period of blocked blood supply, and affects a large portion of the myocardium. It causes significant changes on the electrocardiogram and in the level of blood chemical markers.

2. Non-ST segment elevation myocardial infarction (NSTEMI). This type of heart attack is caused by a partial or temporary blockage in the blood supply and the extent of the damages is minimal. NSTEMI does not causes changes on the electrocardiogram, however the blood markers will indicate the occurrence of a heart attack by illustrating the tissue damage which has occurred.

III. According to the third criterion, there are two types of heart attacks:

1. Transmural myocardial infarction. This type of heart attack results in the death of the three layers of tissue (epicardium, myocardium, and endocardium) of the myocardial wall.

2. Nontransmural myocardial infarction. This type of heart attack results in the death of a limited area of myocardial wall tissue.

Article by Alina Morrow, MS
Medical Writer
OmniMedicalSearch.com