![]() For example, 10 min of ischemia generally results in about 50 % depletion of ATP after approximately 30 min of normothermic ischemia without significant collateral blood flow, irreversible damage or necrosis occurs. As an ischemic episode becomes more severe or prolonged, the heart becomes unable to produce enough energy via glycolysis and cellular necrosis ensues. Even though energy production continues in the absence of oxygen, the glycolytic pathway is an inefficient means for producing ATP. Consequently, sarcolemmal glucose transport increases, and intracellular acidosis resulting from a buildup of the glycolytic breakdown products causes further inhibition of the contractile apparatus. ![]() During short-term ischemic episodes, the heart’s defense mechanism seeks to remedy this imbalance by downregulating myocardial contractile function and, concomitantly, increasing the rate of glycolysis (anaerobic energy production) from preferred lipid metabolism. The basic definition of myocardial ischemia is a greater myocardial tissue oxygen demand than supply.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |