Medical Terminology : Ischemia and Infarct

What is Ischemia?

Ischemia is the medical term for an inadequate blood supply to a specific area of the body. This results in a reduced oxygen supply as blood has difficulty in reaching the target tissues or organs. Ischemia can be partial or complete. Partial ischemia may cause hypoxia, which is too little oxygen reaching the area. Complete ischemia results in anoxia, where no oxygen reaches the target area, and if this is not corrected quickly, it will eventually lead to an infarct.

Example : Coronary artery disease results in narrowing of the blood vessels that supply oxygen and nutrients to the heart muscle. Less oxygen is able to reach the heart muscle resulting in ischemia which is sometimes experienced as chest pain, known as angina.

Infarct is the when there is death of tissue with surrounding inflammation due to a sudden and complete loss of arterial blood supply. It is often preceded by ischemic injury but if it is gradual and there is only partial ischemia, the body can quickly develop collateral blood supply to the target area. This means that new vessels will branch of from neighboring arteries to carry oxygenated blood to the area. An infarct is a serious medical condition that causes severe disability or even death, depending on the tissue or organ affected.

Example : Total occlusion (blockage) of a coronary artery can result in a myocardial infarct (heart attack) if there is no collateral blood supply to supplement the oxygen provided by the blocked vessel. This leads to an infarct where a  portion of the heart muscle dies and the surrounding tissue becomes inflamed.

Ischemia and an infarct can occur in any tissue or organ in the body but is the most life threatening when it affects the heart (heart attack) or brain (cerebrovascular accident or stroke). Although ischemia and infarct are often discussed in the context of a blockage in the artery, like plaques in atherosclerosis or a blood clot (thrombus or embolus), it can also arise from a rupture in the artery thereby preventing oxygenated blood from reaching the target tissue.

Article reviewed by Dr. Greg. Last updated on April 24, 2011