Ischemia is reduced blood flow leading to tissue damage, injury refers to reversible tissue damage, and infarction means irreversible tissue death due to prolonged ischemia, as seen in myocardial infarction and strokes.
Ischemia refers to the reduction of blood flow to a tissue, causing a shortage of oxygen and nutrients that can lead to tissue damage. Injury in the medical context often refers to cellular or tissue damage which may be reversible if blood flow is restored promptly.
Infarction corresponds to cell death due to prolonged ischemia, generally considered irreversible, as observed in myocardial infarction (heart attack) or ischemic stroke. In ischemic stroke, a blood clot obstructs an artery in the brain, while in myocardial infarction, blood flow to the heart is blocked, often by atherosclerotic plaques.
In the context of the brain and heart, ischemic conditions can lead to serious consequences. Ischemia in the brain can result in cerebral hypoxia and potential subsequent stroke, while cardiac ischemia due to coronary artery blockage can cause a myocardial infarction, commonly known as a heart attack. The outcomes can be largely impacted by the timing and effectiveness of treatment, like thrombolysis using recombinant tissue plasminogen activator (rtPA).
Infarction occurs when the tissue damage progresses beyond salvage, with cells dying due to lack of oxygenation and nutrients. This progression from ischemia to infarction can occur in both the brain and heart, emphasizing the critical period during which medical intervention can prevent irreversible tissue damage.