What takes place as a result of a myocardial infarction?

Answer 1

Acute myocardial infarction refers to two subtypes of acute coronary syndrome, namely non-ST-elevated myocardial infarction and ST-elevated myocardial infarction, which are most frequently (but not always) a manifestation of coronary artery disease. The most common triggering event is the disruption of an atherosclerotic plaque in an epicardial coronary artery, which leads to a clotting cascade, sometimes resulting in total occlusion of the artery. Atherosclerosis is the gradual buildup of cholesterol and fibrous tissue in plaques in the wall of arteries (in this case, the coronary arteries), typically over decades. Blood stream column irregularities visible on angiography reflect artery lumen narrowing as a result of decades of advancing atherosclerosis. Plaques can become unstable, rupture, and additionally promote a thrombus (blood clot) that occludes the artery; this can occur in minutes. When a severe enough plaque rupture occurs in the coronary vasculature, it leads to myocardial infarction (necrosis of downstream myocardium). If impaired blood flow to the heart lasts long enough, it triggers a process called the ischemic cascade; the heart cells die (chiefly through necrosis) and do not grow back. A collagen scar forms in its place. Recent studies indicate that another form of cell death called apoptosis also plays a role in the process of tissue damage subsequent to myocardial infarction.[33] As a result, the patient's heart will be permanently damaged. This scar tissue also puts the patient at risk for potentially life threatening arrhythmias, and may result in the formation of a ventricular aneurysm that can rupture with catastrophic consequences. Injured heart tissue conducts electrical impulses more slowly than normal heart tissue. The difference in conduction velocity between injured and uninjured tissue can trigger re-entry or a feedback loop that is believed to be the cause of many lethal arrhythmias. The most serious of these arrhythmias is ventricular fibrillation (V-Fib/VF), an extremely fast and chaotic heart rhythm that is the leading cause of sudden cardiac death. Another life threatening arrhythmia is ventricular tachycardia (V-Tach/VT), which may or may not cause sudden cardiac death. However, ventricular tachycardia usually results in rapid heart rates that prevent the heart from pumping blood effectively. Cardiac output and blood pressure may fall to dangerous levels, which can lead to further coronary ischemia and extension of the infarct. The cardiac defibrillator is a device that was specifically designed to terminate these potentially fatal arrhythmias. The device works by delivering an electrical shock to the patient in order to depolarize a critical mass of the heart muscle, in effect "rebooting" the heart. This therapy is time dependent, and the odds of successful defibrillation decline rapidly after the onset of cardiopulmonary arrest.

Answer 2

The pathophysiology of acute myocardial infarction is complex. Loss of viable myocardium impairs global cardiac function, which can lead to reduced cardiac output, and if damage is severe, to cardiogenic shock. Systolic and diastolic dysfunction are associated with ischemic myocardium. If left ventricular function is significantly impaired, pulmonary congestion and edema can occur. Ischemia can also precipitate abnormal cardiac rhythms and conduction blocks that can further impair function and become life-threatening in some cases. Reduced cardiac output and arterial pressure can elicit baroreceptor reflexes that lead to activation of neurohumoral compensatory mechanisms (e.g., activation of sympathetic nerves and the renin-angiotensin-aldosterone system) similar to what occurs during heart failure. The pain and anxiety associated with myocardial infarction further activates the sympathetic nervous system, which causes systemic vasoconstriction and cardiac stimulation (this explains why some patients become hypertensive and have tachycardia). While sympathetic activation helps to maintain arterial pressure, it also leads to a large increase in myocardial oxygen demand that can lead to greater myocardial hypoxia, enlarge the infarcted region, precipitate arrhythmias, and further impair cardiac function. Sympathetic activation is responsible for the diaphoresis (sweating) experienced by the patient. Renal hypoperfusion and sympathetic activation stimulate renin release, which leads to increased plasma levels of angiotensin II and aldosterone that enhance renal retention of sodium and water.

Answer 3

A myocardial infarction (MI) is caused by inadequate oxygen supply to the heart. MI's can be caused by numerous events. The most common type of MI's are caused by blockages in the coronary arteries, which solely supply the heart muscle. This can be due to a thrombosis (a clot formed at the location) or an embolism (a clot or matter that has traveled through the system and lodges at the location).

Other causes of chest pain that may lead to an MI include coronary artery spasm and angina. Although usually temporary and do not cause any damage, chest pain associated with angina or coronary artery spasm must be diagnosed by a doctor.

Answer 4

Myocardial infarction is also called as heart attack in simple words, and it is very common reason resulting to several deaths worldwide. The exact cause of MI is due to narrowing of coronary arteries which leads to reduction or complete stoppage of blood flow to myocardium. Hence, MI is an emergency condition requiring immediate admission of the patient in ICU. Central BioHub is an online human biospecimen marketplace and we offer 700+ high-quality myocardial infarction samples on our website. You can buy clinically graded samples collected from different myocardial infarction patients exclusively for research purpose. To learn more about myocardial infarction samples portfolio, check our website.

Answer 5

what takes place as result of myocardial infarction

Answer 6

Ischemia or a deficiency of blood flow to the heart causes a heart attack.

Answer 7

MI literally means heart tissue death. and the rest of the heart has to work harder to pick up the slack of the dead part.

Answer 8

Areas of the heart involved in a myocardial infarction change in contractility and function, becoming scar tissue that thins and hinders its ability to contract.

Answer 9

yes