Infarction
Infarction refers to a localized area of tissue damage or necrosis resulting from an inadequate blood supply, leading to a lack of oxygen necessary for cellular survival. This condition commonly affects vital organs, including the heart, brain, kidneys, lungs, and intestines, primarily due to the obstruction or spasm of blood vessels. Symptoms of infarction often include severe pain, ischemia (insufficient blood flow), and, depending on the affected area, can lead to significant health complications, including death or disability. Myocardial infarction, commonly known as a heart attack, presents with a classic triad of symptoms: intense chest pain, elevated cardiac enzyme levels, and notable electrocardiographic changes. Treatment options for infarction can vary based on the location and severity but typically involve emergency medical interventions such as thrombolytic therapy to dissolve clots, angioplasty to open blocked vessels, and pain management. Lifestyle modifications, including dietary changes and gradual return to physical activities, are also important in recovery. Understanding the signs and treatment of infarction is crucial for timely medical intervention to minimize its serious consequences.
Infarction
ALSO KNOWN AS: Heart attack, stroke, acute abdomen
ANATOMY OR SYSTEM AFFECTED: Blood vessels, brain, heart, intestine, kidneys, lungs
DEFINITION: A localized area of tissue damage or necrosis caused by absence of blood supply and oxygen to the part
CAUSES: Lack of blood supply from obstruction, blockage, or spasm of blood vessel supplying organ affected
SYMPTOMS: Pain, ischemia, necrosis
DURATION: Acute
TREATMENTS: Bed rest, oxygen, thrombolytic medications, nitroglycerine, morphine, stool softeners, low-sodium diet, surgery
Causes and Symptoms
“Infarct” is the term used to indicate a localized area of necrosis resulting when the blood supply to an area falls below the level required for cells to survive. Infarction results from the of an artery at a point that causes the main blood supply to be blocked. It also occurs when the tissue requirements are raised above the capacity of the diseased vessels to deliver blood. Although an infarction may occur in any tissue, those that require a large supply of blood are particularly vulnerable. Organs in which infarctions are commonly found are the brain, heart, intestine, kidney, and lung. The consequences of an infarction depend on its location and extent. If the infarcted area is extensive enough, then function of the organ is compromised and death or disability may result. A large infarct in a vital organ such as the heart, lung, or may be responsible for sudden death.
Symptoms related to infarction include the development of tissue ischemia. The most marked manifestation of acute is pain. Fear and are other symptoms that may be exhibited. Myocardial infarction, commonly called a heart attack, is classically associated with a characteristic diagnostic triad. First, there is a clinical picture consisting of severe, prolonged chest pain, frequently associated with sweating, nausea, vomiting, and a sense of impending doom. Second, levels of the cardiac enzymes released by the necrotic myocardial cells are elevated. Finally, electrocardiographic changes are evident.
Treatment and Therapy
Acute myocardial infarction requires immediate admission to a hospital with a coronary care unit. Continuous close monitoring of cardiac rhythms and enzymatic changes is especially important. The first twenty-four hours after onset of symptoms is the time of highest risk for sudden death. Myocardial infarction caused by intracoronary thrombi (clots) can be relieved by infusion of thrombolytic agents that dissolve the clots and promote vasodilation. The treatment must be performed within three to four hours after the onset of infarction and can reestablish blood flow in approximately three minutes. Angioplasty to open blood vessels that are blocked or narrowed is often the first choice of treatment and should be performed as soon as possible and no more than twelve hours after a heart attack. A stent may be placed during or after angioplasty to help keep the artery open. Bed rest followed by a gradual return to activities of daily living reduces the myocardial oxygen demands of the compromised heart.
Pain relief is of utmost importance. If sublingual nitroglycerin is ineffective, then small, carefully titrated doses of morphine sulfate may be given for and vasodilation. Supplementary oxygen is administered to increase arterial oxygen content and deliver more oxygen to the ischemic myocardium. Dietary measures are aimed at preventing and vomiting, and consumption of sodium, saturated fats, sugar, and is limited. In addition to pain relief, pharmacologic intervention is used to limit infarction size, reduce vasoconstriction, prevent formation, and augment repair. Treatment for infarction of the brain, kidney, and bowel may require surgery to reestablish and remove necrotic tissue.
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