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
Potential new heart attack biomarker uncovered
Dec 10, 2009 |
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Though they remain a leading killer, heart attacks can be effectively treated provided they can be rapidly diagnosed following initial onset of symptoms. In a study appearing in this month's Molecular and Cellular Proteomics, resear ...
Scientists discover gene module underlying atherosclerosis development
Dec 04, 2009 |
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By measuring the total gene activity in organs relevant for coronary artery disease (CAD), scientists at the Swedish medical university Karolinska Institutet have identified a module of genes that is important for the recruitment ...
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.
High vs. low hospital volume for angioplasty finds little difference in death rates
Nov 24, 2009 |
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A study based on a contemporary registry of patients with myocardial infarction (heart attack) indicates that even though hospitals that perform a higher number of angioplasties are more likely to follow evidence-based guidelines ...
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 ...
Survival after heart attack improves in younger women
Oct 26, 2009 |
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In recent years, women, particularly younger women, experienced larger improvements in hospital mortality after myocardial infarction (MI) than men, according to a study published in the Oct. 26, 2009 issue of Archives of ...
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
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.
Cardiac biomarker levels strongly predict outcome of bypass surgery
Sep 04, 2009 |
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Levels of a biomarker used in the diagnosis of heart attacks are almost universally elevated in patients who have undergone coronary-artery bypass grafting (CABG) and, when markedly elevated, are powerfully prognostic, a ...
Pre-hospital organization: The first links in the chain of survival for heart attack patients
Sep 01, 2009 |
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Mortality rate following a heart attack has fallen by more than 50% in Europe over the past 25 years. However, because only minor advances in the medical treatment of AMI are expected over the next decade, it is through organisational ...
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, ...
New strategies for reperfusion therapy
Aug 31, 2009 |
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PCI is the preferred strategy in acute myocardial infarction when performed by an experienced team as soon as possible after first medical contact.Time is essential: for P-PCI there is an 8 percent excess annual mortality ...
No increased risk with drug eluting stents -- but late stent thrombosis remains a concern
Aug 31, 2009 |
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Several large observational data sets have convincingly shown that there is no overall safety issue with drug eluting stents (DES) vs. bare metal stents (BMS). In fact, most registry studies suggest a lower risk of death ...
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.
Women slightly more likely to die than men in the 30 days following a heart attack
Aug 25, 2009 |
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A new study from NYU School of Medicine found that women may have a slightly higher risk of death than men in the thirty days following an acute coronary syndrome (ACS), but that these differences appear to be attributable ...
