Ischemia

Definition

Tissue ischemia occurs when there is insufficient oxygen supply to an organ, usually resulting from an occlusion of an artery that normally provides blood supply to that organ, frequently caused by atherosclerosis. The specific symptoms depend on the location and severity of the occlusion, the specific organ involved, and whether and the speed with which the blood supply is restored. Myocardial ischemia occurs when coronary artery disease causes the heart muscle to be deprived of sufficient oxygen to do its pumping, causing certain cardiac symptoms such as angina or fatigue. Cerebral ischemia occurs when carotid artery stenosis limits blood supply to selected regions of the brain, causing various neurological and neuropsychological findings that depending primarily on the affected region. Approximately, 80% of all strokes are ischemic. Ischemic episodes occur suddenly, last a few minutes to a few hours, and are strong warning signs of an impending myocardial infarction or...