Coronary Artery Anatomy

Coronary Artery Pathology

The occlusion of a coronary artery is often associated with atherosclerosis. A partial or total blockage prevents the flow of arterial blood beyond the site of the stenosis, causing ischemia, angina and/or ischemic necrosis of the myocardium which is referred to as a myocardial infarction (MI). Less often, coronary vessels may be occluded by fat globules, tumor emboli or clot emboli from other parts of the body, though this usually occurs at sites of pre-existing stenosis. The spasm of a coronary artery can also occur producing the same results.

Atherosclerosis is a disease caused by faulty or incomplete lipid metabolism. The body fails to metabolize fats normally, thus cholesterol, phospholipid and neutral fat are deposited on the walls of arteries. Over time the body builds fibrous tissue around these fatty deposits (called plaques) which can become calcified into "bony-hard" plates in later stages. This process can occur in any artery.

These plaques and/or plates can cause acute occlusion three ways: 1) the fatty deposit may break through the inner wall of the vessel, thus occluding it, 2) the fatty deposit may dislodge and occlude a smaller vessel distally, and 3) fatty deposits may erode the arterial wall resulting in a hematoma which totally or partially occludes the lumen of the artery.

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