Myocardial infarction
hideMyocardial infarction (MI or AMI for acute myocardial infarction), commonly known as a heart attack, occurs when the blood supply to part of the heart is interrupted causing some heart cells to die. This is most commonly due to occlusion (blockage) of a coronary artery following the rupture of a vulnerable atherosclerotic plaque, which is an unstable collection of lipids (like cholesterol) and white blood cells (especially macrophages) in the wall of an artery. The resulting ischemia (restriction in blood supply) and oxygen shortage, if left untreated for a sufficient period of time, can cause damage and / or death (infarction) of heart muscle tissue (myocardium).
Classical symptoms of acute myocardial infarction include sudden chest pain (typically radiating to the left arm or left side of the neck), shortness of breath, nausea, vomiting, palpitations, sweating, and anxiety (often described as a sense of impending doom). Women may experience fewer typical symptoms than men, most commonly shortness of breath, weakness, a feeling of indigestion, and fatigue. Approximately one quarter of all myocardial infarctions are silent, without chest pain or other symptoms. A heart attack is a medical emergency, and people experiencing chest pain are advised to alert their emergency medical services, because prompt treatment can be crucial to survival.
Heart attacks are the leading cause of death for both men and women all over the world. Important risk factors are previous cardiovascular disease (such as angina, a previous heart attack or stroke), older age (especially men over 40 and women over 50), tobacco smoking, high blood levels of certain lipids (triglycerides, low-density lipoprotein or "bad cholesterol") and low levels of high density lipoprotein (HDL, "good cholesterol"), diabetes, high blood pressure, obesity, chronic kidney disease, heart failure, excessive alcohol consumption, the abuse of certain drugs (such as cocaine and methamphetamine), and chronic high stress levels.
Immediate treatment for suspected acute myocardial infarction includes oxygen, aspirin, and sublingual glyceryl trinitrate (colloquially referred to as nitroglycerin and abbreviated as NTG or GTN). Pain relief is also often given, classically morphine sulfate. A 2009 review however about the use of high flow oxygen for treating myocardial infarction found its administration increased mortality and infarct size, calling into question the recommendation for its routine use.
The patient will receive a number of diagnostic tests, such as an electrocardiogram (ECG, EKG), a chest X-ray and blood tests to detect elevations in cardiac markers (blood tests to detect heart muscle damage). The most often used markers are the creatine kinase-MB (CK-MB) fraction and the troponin I (TnI) or troponin T (TnT) levels. On the basis of the ECG, a distinction is made between ST elevation MI (STEMI) or non-ST elevation MI (NSTEMI). Most cases of STEMI are treated with thrombolysis or if possible with percutaneous coronary intervention (PCI, angioplasty and stent insertion), provided the hospital has facilities for coronary angiography. NSTEMI is managed with medication, although PCI is often performed during hospital admission. In patients who have multiple blockages and who are relatively stable, or in a few extraordinary emergency cases, bypass surgery of the blocked coronary artery is an option.
The phrase "heart attack" is sometimes used incorrectly to describe sudden cardiac death, which may or may not be the result of acute myocardial infarction. A heart attack is different from, but can be the cause of cardiac arrest, which is the stopping of the heartbeat, and cardiac arrhythmia, an abnormal heartbeat. It is also distinct from heart failure, in which the pumping action of the heart is impaired; severe myocardial infarction may lead to heart failure, but not necessarily.
For more information about Myocardial infarction, read the full article at
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News tagged with myocardial infarction
Chocolate cuts death rate in heart attack survivors: study
Aug 13, 2009 |
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Heart attack survivors who eat chocolate two or more times per week cut their risk of dying from heart disease about threefold compared to those who never touch the stuff, scientists have reported.
30-year follow-up study: 'Tremendous' impact of smoking on mortality and cardiovascular disease
May 08, 2009 |
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Non-smokers live longer and have less cardiovascular disease than those who smoke, according to a 30-year follow-up study of 54,000 men and women in Norway. Smoking, say the investigators, is "strongly" related to cardiovascular ...
Tunnels concentrate air pollution by up to 1,000 times
Aug 27, 2009 |
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A toxic cocktail of ultrafine particles is lurking inside road tunnels in concentration levels so high they have the potential to harm drivers and passengers, a new study has found.
Poor leadership poses a health risk at work
Nov 02, 2009 |
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Perceived poor managerial leadership increases not only the amount of sick leave taken at a workplace, but also the risk of sickness amongst employees later on in life. The longer a person has had a "poorer" manager, the ...
Daytime sleepiness provides red flag for cardiovascular disease
Feb 26, 2009 |
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Clinicians should be alert to patients reporting "excessive" day time sleepiness (EDS), says the European Society of Cardiology, after a French study found healthy elderly people who regularly report feeling sleepy during ...
Scientists find shared genetic link between periodontitis and heart attack
May 25, 2009 |
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The relationship between the dental disease periodontitis and coronary heart disease (CHD) has been known for several years. Although a genetic link seemed likely, until now its existence was uncertain. Now, for the first ...
No major role for fish in the prevention of heart failure
Sep 30, 2009 |
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'No major role for fish' in the prevention of heart failure; only a possible beneficial effect in those with diabetes
Study shows emergency physicians have good first instincts in diagnosing heart attacks
Jul 24, 2008 |
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A study out of Wake Forest University Baptist Medical Center demonstrates emergency room doctors are correctly identifying patients who are having a heart attack, even when laboratory tests haven't yet confirmed it.
Elderly patients can benefit from selective use of early revascularization
Feb 16, 2009 |
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The elderly represent a growing proportion of patients presenting with acute myocardial infarction (MI) complicated by cardiogenic shock (CS). CS occurs when the heart fails to supply enough blood to the organs of the body, ...
Kidney disease linked to lower medication use after heart attack
Jul 09, 2008 |
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Patients with kidney disease—especially end-stage renal disease (ESRD) requiring dialysis—are less likely to receive recommended medications after a heart attack, reports a study in the September 2008 Clinical Journal of ...
Stem cell transplant in mouse embryo yields heart protection in adulthood
May 14, 2009 |
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Stem cells play a role in heart muscle rejuvenation by attracting cells from the body that develop into heart muscle cells. They have been successfully used to halt or reverse cardiac injury following heart attack, but not ...
Stent for life initiative
Sep 01, 2009 |
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Primary angioplasty (with stent implantation) is the most effective therapy for acute myocardial infarction (AMI), but it is not available to many patients, even though most European countries have sufficient resources (ie, ...
Popular diabetes drugs linked to increased risk of heart failure and death
Medicine & Health / Medications
Dec 04, 2009 |
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Sulphonylureas, a type of drug widely used to treat type 2 diabetes, carries a greater risk of heart failure and death compared with metformin, another popular antidiabetes drug.
Low neighborhood income, Medicaid linked to delays in reaching hospital after heart attack
Sep 22, 2008 |
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Individuals with Medicaid insurance and those who live in neighborhoods with lower household incomes appear less likely than others to reach the hospital within two hours of having a heart attack, according to a report in ...
Flu boosts heart-attack risk, says study
Sep 21, 2009 |
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Heart problems may account for a huge share of deaths from influenza, according to a study published on Tuesday that recommends cardiac patients be vaccinated against flu.
