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Myocardial infarction

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Myocardial 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 Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.


News tagged with heart attack

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Quintet of proteins forms new, early-warning blood test before heart attack strikes

Chemistry /

created Nov 09, 2008 | popularity 4.5 / 5 (11) | comments 0

A team of Johns Hopkins biochemists has identified a mixed bag of five key proteins out of thousands secreted into blood draining from the heart's blood vessels that may together or in certain quantities form the basis of ...


Chocolate cuts death rate in heart attack survivors: study

Medicine & Health / Research

created Aug 13, 2009 | popularity 4.4 / 5 (9) | comments 4

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.


Piece from childhood virus may save soldiers' lives

Medicine & Health / Research

created Sep 06, 2009 | popularity 4.4 / 5 (9) | comments 1

A harmless shard from the shell of a common childhood virus may halt a biological process that kills a significant percentage of battlefield casualties, heart attack victims and oxygen-deprived newborns, according to research ...


World-first high blood pressure treatment trialled in Melbourne

Medicine & Health / Research

created Apr 03, 2009 | popularity 4.9 / 5 (8) | comments 0

A world-first breakthrough to treat high blood pressure has been successfully trialled in Melbourne.


The food-energy cellular connection revealed

Medicine & Health / Research

created Oct 15, 2009 | popularity 4.6 / 5 (8) | comments 1

Our body's activity levels fall and rise to the beat of our internal drums—the 24-hour cycles that govern fundamental physiological functions, from sleeping and feeding patterns to the energy available to our cells. Whereas ...


Scientists grow mice heart muscle strip that beats

Scientists grow mice heart muscle strip that beats

Medicine & Health / Research

created Oct 15, 2009 | popularity 5 / 5 (7) | comments 0

(PhysOrg.com) -- Scientists have grown a piece of heart muscle - and then watched it beat - by using stem cells from a mouse embryo, a big step toward one day repairing damage from heart attacks.


Reducing the damage of a heart attack: Mechanism behind cardiac scarring discovered

Biology /

created Dec 15, 2008 | popularity 4.7 / 5 (7) | comments 0

In the aftermath of a heart attack, the body's own defenses may contribute to future heart failure. Authors of a new study believe they have identified a protein that plays an important role in a process that replaces dead ...


Heart attacks: The tipping point

Heart attacks: The tipping point

Biology / Biotechnology

created Apr 27, 2009 | popularity 5 / 5 (6) | comments 0

Twenty percent of American deaths each year are caused by heart attack or angina, sometimes without any warning.


Unexpected reservoir of monocytes discovered in the spleen

Medicine & Health / Research

created Jul 30, 2009 | popularity 5 / 5 (6) | comments 0

It takes a spleen to mend a broken heart - that's the conclusion of a surprising new report from researchers at the Massachusetts General Hospital (MGH) Center for Systems Biology, directed by Ralph Weissleder, MD, PhD. ...


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Alcohol helps lower heart disease risk for men: study

Medicine & Health / Health

created Nov 19, 2009 | popularity 4.3 / 5 (7) | comments 7

Men who drink alcohol every day see a nearly one-third average reduction in the risk of coronary heart disease, according to a long-term study among Spanish men published on Thursday.


Blood pressure targets: Aiming lower offers no benefit

Medicine & Health / Research

created Jul 08, 2009 | popularity 4.5 / 5 (6) | comments 0

Aiming for lower than standard blood pressure targets offers no known clinical benefit, according to a Cochrane Review. In a systematic review of the evidence, researchers found that using antihypertensive drugs to reduce ...


The more oral bacteria, the higher the risk of heart attack

Medicine & Health / Research

created Apr 01, 2009 | popularity 4.2 / 5 (6) | comments 0

Several studies have suggested there is a connection between organisms that cause gum disease, known scientifically as periodontal disease, and the development of heart disease, but few studies have tested this theory.


Molecule prompts damaged heart cells to repair themselves after a heart attack

Molecule prompts damaged heart cells to repair themselves after a heart attack

Medicine & Health / Research

created Apr 10, 2009 | popularity 5 / 5 (5) | comments 0

A protein that the heart produces during its early development reactivates the embryonic coronary developmental program and initiates migration of heart cells and blood vessel growth after a heart attack, ...


Study shows common pain cream could protect heart during attack

Study shows common pain cream could protect heart during attack

Medicine & Health / Research

created Sep 14, 2009 | popularity 5 / 5 (5) | comments 1

(PhysOrg.com) -- New research from the University of Cincinnati (UC) shows that a common, over-the-counter pain salve rubbed on the skin during a heart attack could serve as a cardiac-protectant, preventing ...


New findings on the role of inflammation in prevention of coronary heart disease

Medicine & Health / Diseases

created Nov 10, 2008 | popularity 3.7 / 5 (6) | comments 0

This year, about 450,000 Americans will die of coronary heart disease – the leading cause of death for both men and women. Although we have made great strides in preventing and treating heart disease, we continue to explore ...