Question

Explain every stage of the evolution of the Ischemic heart disease please (no handwriting please)

Answer 1

ischemia occurs when blood flow to your heart is reduced, preventing the heart muscle from receiving enough oxygen. The reduced blood flow is usually the result of a partial or complete blockage of your heart's arteries ,the coronary arteries.Sudden, severe blockage of one of the heart's artery can lead to a heart attack.

In Ischemia the part of the smooth, elastic lining inside a coronary artery, develops atherosclerosis, inside of the artery narrows because of build up of plaque these plaques are mainly made up of cholesterol, overtime the arteries linings become hardened and stiffened and there is deposition of fatty lipids and abnormal inflamatory cells and moreover calcium phosphate crystals starts to deposit on the muscular layer of blood vessel, all these accumulates to form lump, which than protrude into channel of artery, this could cause obstruction to the flow of blood, this could be partial or complete. With obstruction it can limit the supply of blood to the myocardial tissue, this in turn can damage the cardiac tissue. Atherosclerosis occurs in three major stages,  fatty streak, plaque progression and disruption. Various factors cause the formation of free radicals, these radicals interact with other ions, this causes oxidative stress leading to endothelium dysfunction, allowing lipoproteins, calcium and fibrous tissues to enter and modify intima layer of the blood vessel, this change in the tissue layer causes the recruitment of various whiteblood cells, which in recruits various growth factors, like platelet-derived growth factor (PDGF), and transforming growth factor, etc, all these lead to development of foam cells which are the yellowish fatty streaks, Plaque growth progresses when smooth muscle migrates to intima. PDGF allows smooth muscle to proliferate for collagen synthesis whereas transforming growth factor stimulate the process losing the arterial wall’s elasticity, all this results in fibrous tissue cap, and inhibition of collagen synthesis, Disruption occurs when plaques rupture triggering a coagulation cascade where thrombus and fibrin deposit in arterial wall further reducing lumen diameter and cause coronary blockage, this in turn can cause impaired blood flow to part of heart muscles leading to tissue hypoxia, which all can lead to myocardial infraction or heart attack