Ischemia

This is a decreased arterial blood supply to tissues or an organ. It usually occurs due to vascular lumen narrowing (atherosclerotic plaques), lumen obstruction (obstructions) (thrombi, emboli), external compression (tumors, etc.), prolonged spasm (smoking, etc.). The heart, kidneys, and brain are organs most likely affected by impaired blood flow at certain periods. Ischemic heart disease is an acute or chronic myocardial disease resulting from decreased myocardial blood supply and manifests as acute or chronic ischemic syndromes such as stable and unstable angina, myocardial infarction. During myocardial ischemia, anaerobic metabolism prevails in the heart muscle, while oxidation and oxidative phosphorylation reactions weaken. In the early period of myocardial ischemia, increased catecholamines and cAMP intracellular concentrations promote the formation of phosphorilase a and increase phosphofructokinase activity; glycolysis and glycogenolysis processes are activated. However, after the rapid depletion of glycogen reserves, increased acidosis inhibits phosphofructokinase.

Source | Glossary of Most Commonly Used Biomedical Terms and Concepts | Lithuanian University of Health Sciences | Academician Professor Antanas Praškevičius, Professor Laima Ivanovienė