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78-404: A myocardial infarction ( MI ), commonly known as a heart attack , occurs when blood flow decreases or stops in one of the coronary arteries of the heart , causing infarction (tissue death) to the heart muscle . The most common symptom is retrosternal chest pain or discomfort that classically radiates to the left shoulder, arm, or jaw. The pain may occasionally feel like heartburn . This

156-409: A blood test for biomarkers (the cardiac protein troponin ). When there is evidence of an MI, it may be classified as an ST elevation myocardial infarction (STEMI) or Non-ST elevation myocardial infarction (NSTEMI) based on the results of an ECG . The phrase "heart attack" is often used non-specifically to refer to myocardial infarction. An MI is different from—but can cause— cardiac arrest , where

234-471: A coronary artery caused by a rupture of an atherosclerotic plaque is usually the underlying mechanism of an MI. MIs are less commonly caused by coronary artery spasms , which may be due to cocaine , significant emotional stress (often known as Takotsubo syndrome or broken heart syndrome ) and extreme cold, among others. Many tests are helpful to help with diagnosis, including electrocardiograms (ECGs), blood tests and coronary angiography . An ECG, which

312-471: A benefit of 15 to 45%. Physical activity can reduce the risk of cardiovascular disease, and people at risk are advised to engage in 150 minutes of moderate or 75 minutes of vigorous intensity aerobic exercise a week. Keeping a healthy weight, drinking alcohol within the recommended limits, and quitting smoking reduce the risk of cardiovascular disease. Substituting unsaturated fats such as olive oil and rapeseed oil instead of saturated fats may reduce

390-431: A disruption in blood supply. The blood vessel supplying the affected area of tissue may be blocked due to an obstruction in the vessel (e.g., an arterial embolus , thrombus , or atherosclerotic plaque ), compressed by something outside of the vessel causing it to narrow (e.g.,  tumor , volvulus , or hernia ), ruptured by trauma causing a loss of blood pressure downstream of the rupture, or vasoconstricted, which

468-446: A few hours. Paralysis is a very late sign of acute arterial ischemia and signals the death of nerves supplying the extremity. Foot drop may occur as a result of nerve damage . Because nerves are extremely sensitive to hypoxia , limb paralysis or ischemic neuropathy may persist after revascularization and may be permanent. Cardiac ischemia may be asymptomatic or may cause chest pain, known as angina pectoris . It occurs when

546-429: A myocardial infarction before age 55 years, or a female first-degree relative (mother, sister) less than age 65 increases a person's risk of MI. Genome-wide association studies have found 27 genetic variants that are associated with an increased risk of myocardial infarction. The strongest association of MI has been found with chromosome 9 on the short arm p at locus 21, which contains genes CDKN2A and 2B, although

624-459: A myocardial infarction increases with older age, low physical activity, and low socioeconomic status . Heart attacks appear to occur more commonly in the morning hours, especially between 6AM and noon. Evidence suggests that heart attacks are at least three times more likely to occur in the morning than in the late evening. Shift work is also associated with a higher risk of MI. One analysis has found an increase in heart attacks immediately following

702-403: A myocardial infarction. Spasm of coronary arteries, such as Prinzmetal's angina may cause blockage. If impaired blood flow to the heart lasts long enough, it triggers a process called the ischemic cascade ; the heart cells in the territory of the blocked coronary artery die ( infarction ), chiefly through necrosis , and do not grow back. A collagen scar forms in their place. When an artery

780-538: A myocardial infarction. The flow of blood can be imaged, and contrast dyes may be given to improve image. Other scans using radioactive contrast include SPECT CT-scans using thallium , sestamibi ( MIBI scans ) or tetrofosmin ; or a PET scan using Fludeoxyglucose or rubidium-82 . These nuclear medicine scans can visualize the perfusion of heart muscle. SPECT may also be used to determine viability of tissue, and whether areas of ischemia are inducible. Medical societies and professional guidelines recommend that

858-632: A person localizes the chest pain by clenching one or both fists over their sternum , has classically been thought to be predictive of cardiac chest pain, although a prospective observational study showed it had a poor positive predictive value . Typically, chest pain because of ischemia, be it unstable angina or myocardial infarction, lessens with the use of nitroglycerin , but nitroglycerin may also relieve chest pain arising from non-cardiac causes. Chest pain may be accompanied by sweating , nausea or vomiting, and fainting , and these symptoms may also occur without any pain at all. Dizziness or lightheadedness

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936-404: A previous heart attack is also suggestive. The pain associated with MI is usually diffuse, does not change with position, and lasts for more than 20 minutes. It might be described as pressure, tightness, knifelike, tearing, burning sensation (all these are also manifested during other diseases). It could be felt as an unexplained anxiety, and pain might be absent altogether. Levine's sign , in which

1014-551: A rise in biomarkers, a rise in the ST segment , changes in the shape or flipping of T waves , new Q waves , or a new left bundle branch block can be used to diagnose an AMI. In addition, ST elevation can be used to diagnose an ST segment myocardial infarction (STEMI). A rise must be new in V2 and V3 ≥2 mm (0,2 mV) for males or ≥1.5 mm (0.15 mV) for females or ≥1 mm (0.1 mV) in two other adjacent chest or limb leads . ST elevation

1092-405: A series of leads placed on a person's chest that measure electrical activity associated with contraction of the heart muscle. The taking of an ECG is an important part of the workup of an AMI, and ECGs are often not just taken once but may be repeated over minutes to hours, or in response to changes in signs or symptoms. ECG readouts produce a waveform with different labeled features. In addition to

1170-403: A significant effect on blood cholesterol and thus recommendations about its consumption may not be needed. Trans fats do appear to increase risk. Acute and prolonged intake of high quantities of alcoholic drinks (3–4 or more daily) increases the risk of a heart attack. Family history of ischemic heart disease or MI, particularly if one has a male first-degree relative (father, brother) who had

1248-423: A vessel from compression , shearing , or laceration . Acute arterial occlusion may develop as a result of arterial dissection in the carotid artery or aorta or as a result of iatrogenic arterial injury (e.g., after angiography ). An inadequate flow of blood to a part of the body may be caused by any of the following: Ischemia results in tissue damage in a process known as ischemic cascade . The damage

1326-703: Is a vascular disease involving an interruption in the arterial blood supply to a tissue , organ , or extremity that, if untreated, can lead to tissue death. It can be caused by embolism , thrombosis of an atherosclerotic artery, or trauma. Venous problems like venous outflow obstruction and low-flow states can cause acute arterial ischemia . An aneurysm is one of the most frequent causes of acute arterial ischemia. Other causes are heart conditions including myocardial infarction , mitral valve disease , chronic atrial fibrillation , cardiomyopathies , and prosthesis , in all of which thrombi are prone to develop. The thrombi may dislodge and may travel anywhere in

1404-594: Is a known risk factor, particularly high low-density lipoprotein , low high-density lipoprotein , and high triglycerides . Many risk factors for myocardial infarction are potentially modifiable, with the most important being tobacco smoking (including secondhand smoke ). Smoking appears to be the cause of about 36% and obesity the cause of 20% of coronary artery disease . Lack of physical activity has been linked to 7–12% of cases. Less common causes include stress-related causes such as job stress , which accounts for about 3% of cases, and chronic high stress levels. There

1482-447: Is a recording of the heart's electrical activity, may confirm an ST elevation MI ( STEMI ), if ST elevation is present. Commonly used blood tests include troponin and less often creatine kinase MB . Treatment of an MI is time-critical. Aspirin is an appropriate immediate treatment for a suspected MI. Nitroglycerin or opioids may be used to help with chest pain; however, they do not improve overall outcomes. Supplemental oxygen

1560-460: Is adequate. The signs and symptoms of ischemia vary, as they can occur anywhere in the body and depend on the degree to which blood flow is interrupted. For example, clinical manifestations of acute limb ischemia (which can be summarized as the "six P's" ) include pain , pallor , pulseless , paresthesia , paralysis , and poikilothermia . Without immediate intervention, ischemia may progress quickly to tissue necrosis and gangrene within

1638-495: Is associated with infarction, and may be preceded by changes indicating ischemia, such as ST depression or inversion of the T waves. Abnormalities can help differentiate the location of an infarct, based on the leads that are affected by changes. Early STEMIs may be preceded by peaked T waves. Other ECG abnormalities relating to complications of acute myocardial infarctions may also be evident, such as atrial or ventricular fibrillation . Noninvasive imaging plays an important role in

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1716-508: Is blocked, cells lack oxygen , needed to produce ATP in mitochondria . ATP is required for the maintenance of electrolyte balance, particularly through the Na/K ATPase . This leads to an ischemic cascade of intracellular changes, necrosis and apoptosis of affected cells. Cells in the area with the worst blood supply, just below the inner surface of the heart ( endocardium ), are most susceptible to damage. Ischemia first affects this region,

1794-431: Is common and occurs due to reduction in oxygen and blood to the brain. In females, the most common symptoms of myocardial infarction include shortness of breath, weakness, and fatigue . Females are more likely to have unusual or unexplained tiredness and nausea or vomiting as symptoms. Females having heart attacks are more likely to have palpitations, back pain, labored breath, vomiting, and left arm pain than males, although

1872-399: Is essential to keep the affected organ viable. The treatment options include injection of an anticoagulant , thrombolysis , embolectomy , surgical revascularization, or partial amputation. Anticoagulant therapy is initiated to prevent further enlargement of the thrombus . Continuous IV unfractionated heparin has been the traditional agent of choice. If the condition of the ischemic limb

1950-486: Is exposed to circulating platelets and thrombus formation occurs on the vessel wall occluding blood flow. Occasionally, the plaque may rupture and form an embolus which travels with the blood-flow downstream to where the vessel narrows and eventually clogs the vessel lumen. Infarctions are divided into two types according to the amount of blood present: Diseases commonly associated with infarctions include: Each type of infarction requires its own care. Infarction in

2028-477: Is not the only cause of myocardial infarction, but it may exacerbate or contribute to other causes. A myocardial infarction may result from a heart with a limited blood supply subject to increased oxygen demands, such as in fever, a fast heart rate , hyperthyroidism , too few red blood cells in the bloodstream , or low blood pressure . Damage or failure of procedures such as percutaneous coronary intervention (PCI) or coronary artery bypass grafts (CABG) may cause

2106-426: Is one of the most common symptoms of acute myocardial infarction and is often described as a sensation of tightness, pressure, or squeezing. Pain radiates most often to the left arm, but may also radiate to the lower jaw, neck, right arm, back, and upper abdomen . The pain most suggestive of an acute MI, with the highest likelihood ratio , is pain radiating to the right arm and shoulder. Similarly, chest pain similar to

2184-412: Is recommended in those with low oxygen levels or shortness of breath. In a STEMI, treatments attempt to restore blood flow to the heart and include percutaneous coronary intervention (PCI), where the arteries are pushed open and may be stented , or thrombolysis , where the blockage is removed using medications. People who have a non-ST elevation myocardial infarction ( NSTEMI ) are often managed with

2262-464: Is stabilized with anticoagulation , recently formed emboli may be treated with catheter-directed thrombolysis using intra-arterial infusion of a thrombolytic agent (e.g., recombinant tissue plasminogen activator ( tPA ), streptokinase , or urokinase ). A percutaneous catheter inserted into the femoral artery and threaded to the site of the clot is used to infuse the drug. Unlike anticoagulants , thrombolytic agents work directly to resolve

2340-410: Is still unable to be distributed to the affected myocardium despite clearing the occlusion—also contributes to myocardial injury. Topical endothelial swelling is one of many factors contributing to this phenomenon. A myocardial infarction, according to current consensus, is defined by elevated cardiac biomarkers with a rising or falling trend and at least one of the following: A myocardial infarction

2418-780: Is the dangerous type of Acute coronary syndrome . Other symptoms may include shortness of breath , nausea , feeling faint , a cold sweat , feeling tired , and decreased level of consciousness . About 30% of people have atypical symptoms. Women more often present without chest pain and instead have neck pain, arm pain or feel tired. Among those over 75 years old, about 5% have had an MI with little or no history of symptoms. An MI may cause heart failure , an irregular heartbeat , cardiogenic shock or cardiac arrest . Most MIs occur due to coronary artery disease . Risk factors include high blood pressure , smoking , diabetes , lack of exercise , obesity , high blood cholesterol , poor diet, and excessive alcohol intake . The complete blockage of

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2496-551: Is the narrowing of the blood vessel by contraction of the muscle wall rather than an external force (e.g., cocaine vasoconstriction leading to myocardial infarction ). Hypertension and atherosclerosis are risk factors for both atherosclerotic plaques and thromboembolism . In atherosclerotic formations, a plaque develops under a fibrous cap. When the fibrous cap is degraded by metalloproteinases released from macrophages or by intravascular shear force from blood flow, subendothelial thrombogenic material ( extracellular matrix )

2574-437: Is the result of the build-up of metabolic waste products, inability to maintain cell membranes , mitochondrial damage, and eventual leakage of autolyzing proteolytic enzymes into the cell and surrounding tissues. Restoration of blood supply to ischemic tissues can cause additional damage known as reperfusion injury that can be more damaging than the initial ischemia. Reintroduction of blood flow brings oxygen back to

2652-471: Is tissue death ( necrosis ) due to inadequate blood supply to the affected area. It may be caused by artery blockages , rupture, mechanical compression, or vasoconstriction . The resulting lesion is referred to as an infarct (from the Latin infarctus , "stuffed into"). Infarction occurs as a result of prolonged ischemia , which is the insufficient supply of oxygen and nutrition to an area of tissue due to

2730-454: Is usually clinically classified as an ST-elevation MI (STEMI) or a non-ST elevation MI (NSTEMI). These are based on ST elevation , a portion of a heartbeat graphically recorded on an ECG . STEMIs make up about 25–40% of myocardial infarctions. A more explicit classification system, based on international consensus in 2012, also exists. This classifies myocardial infarctions into five types: There are many different biomarkers used to determine

2808-442: Is varying evidence about the importance of saturated fat in the development of myocardial infarctions. Eating polyunsaturated fat instead of saturated fats has been shown in studies to be associated with a decreased risk of myocardial infarction, while other studies find little evidence that reducing dietary saturated fat or increasing polyunsaturated fat intake affects heart attack risk. Dietary cholesterol does not appear to have

2886-481: The circulatory system , where they may lead to pulmonary embolus , an acute arterial occlusion causing the oxygen and blood supply distal to the embolus to decrease suddenly. The degree and extent of symptoms depend on the size and location of the obstruction , the occurrence of clot fragmentation with embolism to smaller vessels, and the degree of peripheral arterial disease (PAD). Traumatic injury to an extremity may produce partial or total occlusion of

2964-656: The elderly , in those with diabetes mellitus and after heart transplantation . In people with diabetes, differences in pain threshold , autonomic neuropathy , and psychological factors have been cited as possible explanations for the lack of symptoms. In heart transplantation, the donor heart is not fully innervated by the nervous system of the recipient. The most prominent risk factors for myocardial infarction are older age, actively smoking , high blood pressure , diabetes mellitus , and total cholesterol and high-density lipoprotein levels. Many risk factors of myocardial infarction are shared with coronary artery disease ,

3042-478: The health impact assessment of regional and local plans and policies. Most guidelines recommend combining different preventive strategies. A 2015 Cochrane Review found some evidence that such an approach might help with  blood pressure ,  body mass index  and  waist circumference . However, there was insufficient evidence to show an effect on mortality or actual cardio-vascular events. Statins , drugs that act to lower blood cholesterol, decrease

3120-523: The large intestine (colon) is called ischemic colitis . Ischemia of the small bowel is called mesenteric ischemia . Brain ischemia is insufficient blood flow to the brain , and can be acute or chronic . Acute ischemic stroke is a neurological emergency typically caused by a blood clot blocking blood flow in a vessel in the brain. Chronic ischemia of the brain may result in a form of dementia called vascular dementia . A sudden, brief episode (symptoms lasting only minutes) of ischemia affecting

3198-520: The single nucleotide polymorphisms that are implicated are within a non-coding region. The majority of these variants are in regions that have not been previously implicated in coronary artery disease. The following genes have an association with MI: PCSK9 , SORT1 , MIA3 , WDR12 , MRAS , PHACTR1 , LPA , TCF21 , MTHFDSL , ZC3HC1 , CDKN2A , 2B , ABO , PDGF0 , APOA5 , MNF1ASM283 , COL4A1 , HHIPC1 , SMAD3 , ADAMTS7 , RAS1 , SMG6 , SNF8 , LDLR , SLC5A3 , MRPS6 , KCNE2 . The risk of having

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3276-475: The subendocardial region, and tissue begins to die within 15–30 minutes of loss of blood supply. The dead tissue is surrounded by a zone of potentially reversible ischemia that progresses to become a full-thickness transmural infarct. The initial "wave" of infarction can take place over 3–4 hours. These changes are seen on gross pathology and cannot be predicted by the presence or absence of Q waves on an ECG. The position, size and extent of an infarct depends on

3354-549: The sympathetic nervous system , which occurs in response to pain and, where present, low blood pressure . Loss of consciousness can occur in myocardial infarctions due to inadequate blood flow to the brain and cardiogenic shock , and sudden death , frequently due to the development of ventricular fibrillation . When the brain was without oxygen for too long due to a myocardial infarction, coma and persistent vegetative state can occur. Cardiac arrest, and atypical symptoms such as palpitations , occur more frequently in females,

3432-523: The United States. In the developed world, the risk of death in those who have had a STEMI is about 10%. Rates of MI for a given age have decreased globally between 1990 and 2010. In 2011, an MI was one of the top five most expensive conditions during inpatient hospitalizations in the US, with a cost of about $ 11.5 billion for 612,000 hospital stays. Myocardial infarction (MI) refers to tissue death ( infarction ) of

3510-431: The acute diagnostic algorithm; however, it can confirm a clinical suspicion of Chronic Coronary Syndrome when the patient's history, physical examination (including cardiac examination ) ECG, and cardiac biomarkers suggest coronary artery disease. Echocardiography , an ultrasound scan of the heart, is able to visualize the heart, its size, shape, and any abnormal motion of the heart walls as they beat that may indicate

3588-475: The aerobic metabolic rate of the affected cells, reducing the immediate effects of hypoxia . Reduction of body temperature also reduces the inflammation response and reperfusion injury. For frostbite injuries, limiting thawing and warming of tissues until warmer temperatures can be sustained may reduce reperfusion injury . Ischemic stroke is at times treated with various levels of statin therapy at hospital discharge, followed by home time, in an attempt to lower

3666-407: The affected artery, totality of the blockage, duration of the blockage, the presence of collateral blood vessels , oxygen demand, and success of interventional procedures. Tissue death and myocardial scarring alter the normal conduction pathways of the heart and weaken affected areas. The size and location put a person at risk of abnormal heart rhythms (arrhythmias) or heart block , aneurysm of

3744-641: The blood thinner heparin , with the additional use of PCI in those at high risk. In people with blockages of multiple coronary arteries and diabetes, coronary artery bypass surgery (CABG) may be recommended rather than angioplasty . After an MI, lifestyle modifications, along with long-term treatment with aspirin, beta blockers and statins , are typically recommended. Worldwide, about 15.9 million myocardial infarctions occurred in 2015. More than 3 million people had an ST elevation MI, and more than 4 million had an NSTEMI. STEMIs occur about twice as often in men as women. About one million people have an MI each year in

3822-422: The brain is called a transient ischemic attack (TIA), often called a mini-stroke. TIAs can be a warning of future strokes, with approximately 1/3 of TIA patients having a serious stroke within one year. Inadequate blood supply to a limb may result in acute limb ischemia or chronic limb threatening ischemia . Reduced blood flow to the skin layers may result in mottling or uneven, patchy discoloration of

3900-552: The clot over a period of 24 to 48 hours. Direct arteriotomy may be necessary to remove the clot. Surgical revascularization may be used in the setting of trauma (e.g., laceration of the artery). Amputation is reserved for cases where limb salvage is not possible. If the patient continues to have a risk of further embolization from some persistent source, such as chronic atrial fibrillation , treatment includes long-term oral anticoagulation to prevent further acute arterial ischemic episodes. Decrease in body temperature reduces

3978-412: The coronary arteries can be detected with CT scans . Calcium seen in coronary arteries can provide predictive information beyond that of classical risk factors. High blood levels of the amino acid homocysteine is associated with premature atherosclerosis; whether elevated homocysteine in the normal range is causal is controversial. In people without evident coronary artery disease , possible causes for

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4056-401: The day of exposure. Extremes of temperature are also associated. A number of acute and chronic infections including Chlamydophila pneumoniae , influenza , Helicobacter pylori , and Porphyromonas gingivalis among others have been linked to atherosclerosis and myocardial infarction. Myocardial infarction can also occur as a late consequence of Kawasaki disease . Calcium deposits in

4134-402: The diagnosis and characterisation of myocardial infarction. Tests such as chest X-rays can be used to explore and exclude alternate causes of a person's symptoms. Echocardiography may assist in modifying clinical suspicion of ongoing myocardial infarction in patients that can't be ruled out or ruled in following initial ECG and Troponin testing. Myocardial perfusion imaging has no role in

4212-607: The diagnostic accuracy of troponin testing is improving over time. One high-sensitivity cardiac troponin can rule out a heart attack as long as the ECG is normal. Other tests, such as CK-MB or myoglobin , are discouraged. CK-MB is not as specific as troponins for acute myocardial injury, and may be elevated with past cardiac surgery, inflammation or electrical cardioversion; it rises within 4–8 hours and returns to normal within 2–3 days. Copeptin may be useful to rule out MI rapidly when used along with troponin. Electrocardiograms (ECGs) are

4290-411: The elderly, those with diabetes, in people who have just had surgery, and in critically ill patients. "Silent" myocardial infarctions can happen without any symptoms at all. These cases can be discovered later on electrocardiograms , using blood enzyme tests, or at autopsy after a person has died. Such silent myocardial infarctions represent between 22 and 64% of all infarctions, and are more common in

4368-627: The greatest support is the Mediterranean diet . Vitamins and mineral supplements are of no proven benefit, and neither are plant stanols or sterols . Public health measures may also act at a population level to reduce the risk of myocardial infarction, for example by reducing unhealthy diets (excessive salt, saturated fat, and trans-fat) including food labeling and marketing requirements as well as requirements for catering and restaurants and stimulating physical activity. This may be part of regional cardiovascular disease prevention programs or through

4446-462: The heart is not contracting at all or so poorly that all vital organs cease to function, thus leading to death. It is also distinct from heart failure , in which the pumping action of the heart is impaired. However, an MI may lead to heart failure. Chest pain that may or may not radiate to other parts of the body is the most typical and significant symptom of myocardial infarction. It might be accompanied by other symptoms such as sweating. Chest pain

4524-409: The heart muscle ( myocardium ) caused by ischemia , the lack of oxygen delivery to myocardial tissue. It is a type of acute coronary syndrome , which describes a sudden or short-term change in symptoms related to blood flow to the heart. Unlike the other type of acute coronary syndrome, unstable angina , a myocardial infarction occurs when there is cell death , which can be estimated by measuring by

4602-460: The heart muscle, or myocardium , receives insufficient blood flow. This most frequently results from atherosclerosis , which is the long-term accumulation of cholesterol-rich plaques in the coronary arteries . In most Western countries, Ischemic heart disease is the most common cause of death in both men and women, and a major cause of hospital admissions. Both large and small intestines can be affected by ischemia. The blockage of blood flow to

4680-439: The heart ventricles , inflammation of the heart wall following infarction, and rupture of the heart wall that can have catastrophic consequences. Injury to the myocardium also occurs during re-perfusion. This might manifest as ventricular arrhythmia. The re-perfusion injury is a consequence of the calcium and sodium uptake from the cardiac cells and the release of oxygen radicals during reperfusion. No-reflow phenomenon—when blood

4758-724: The heart, lungs , gastrointestinal tract , aorta , and other muscles, bones and nerves surrounding the chest. In addition to myocardial infarction, other causes include angina , insufficient blood supply ( ischemia ) to the heart muscles without evidence of cell death, gastroesophageal reflux disease ; pulmonary embolism , tumors of the lungs, pneumonia , rib fracture , costochondritis , heart failure and other musculoskeletal injuries. Rarer severe differential diagnoses include aortic dissection , esophageal rupture , tension pneumothorax , and pericardial effusion causing cardiac tamponade . The chest pain in an MI may mimic heartburn . Causes of sudden-onset breathlessness generally involve

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4836-400: The incidence and mortality rates of myocardial infarctions. They are often recommended in those at an elevated risk of cardiovascular diseases. Aspirin has been studied extensively in people considered at increased risk of myocardial infarction. Based on numerous studies in different groups (e.g. people with or without diabetes), there does not appear to be a benefit strong enough to outweigh

4914-662: The lungs or heart – including pulmonary edema , pneumonia, allergic reactions and asthma , and pulmonary embolus, acute respiratory distress syndrome and metabolic acidosis . There are many different causes of fatigue, and myocardial infarction is not a common cause. There is a large crossover between the lifestyle and activity recommendations to prevent a myocardial infarction, and those that may be adopted as secondary prevention after an initial myocardial infarction, because of shared risk factors and an aim to reduce atherosclerosis affecting heart vessels. The influenza vaccine also appear to protect against myocardial infarction with

4992-605: The myocardial infarction are coronary spasm or coronary artery dissection . The most common cause of a myocardial infarction is the rupture of an atherosclerotic plaque on an artery supplying heart muscle. Plaques can become unstable, rupture, and additionally promote the formation of a blood clot that blocks the artery; this can occur in minutes. Blockage of an artery can lead to tissue death in tissue being supplied by that artery. Atherosclerotic plaques are often present for decades before they result in symptoms. The gradual buildup of cholesterol and fibrous tissue in plaques in

5070-401: The only symptom, occurring when damage to the heart limits the output of the left ventricle , with breathlessness arising either from low oxygen in the blood or pulmonary edema . Other less common symptoms include weakness, light-headedness , palpitations , and abnormalities in heart rate or blood pressure . These symptoms are likely induced by a massive surge of catecholamines from

5148-406: The organs must be resolved either by treating the cause of the inadequate delivery or reducing the oxygen demand of the system that needs it. For example, patients with myocardial ischemia have a decreased blood flow to the heart and are prescribed with medications that reduce chronotropic and inotropic effect to meet the new level of blood delivery supplied by the stenosed vasculature so that it

5226-414: The physician confirm a person is at high risk for Chronic Coronary Syndrome before conducting diagnostic non-invasive imaging tests to make a diagnosis, as such tests are unlikely to change management and result in increased costs. Patients who have a normal ECG and who are able to exercise, for example, most likely do not merit routine imaging. There are many causes of chest pain , which can originate from

5304-469: The plaque and act to stabilize it. A stable plaque may have a thick fibrous cap with calcification . If there is ongoing inflammation, the cap may be thin or ulcerate. Exposed to the pressure associated with blood flow, plaques, especially those with a thin lining, may rupture and trigger the formation of a blood clot (thrombus). The cholesterol crystals have been associated with plaque rupture through mechanical injury and inflammation. Atherosclerotic disease

5382-485: The presence of cardiac muscle damage. Troponins , measured through a blood test, are considered to be the best, and are preferred because they have greater sensitivity and specificity for measuring injury to the heart muscle than other tests. A rise in troponin occurs within 2–3 hours of injury to the heart muscle, and peaks within 1–2 days. The level of the troponin, as well as a change over time, are useful in measuring and diagnosing or excluding myocardial infarctions, and

5460-499: The primary cause of myocardial infarction, with other risk factors including male sex, low levels of physical activity, a past family history , obesity , and alcohol use . Risk factors for myocardial disease are often included in risk factor stratification scores, such as the Framingham Risk Score . At any given age, men are more at risk than women for the development of cardiovascular disease. High levels of blood cholesterol

5538-408: The risk of adverse events. The Infarct Combat Project (ICP) is an international nonprofit organization founded in 1998 to fight ischemic heart diseases through education and research. The word ischemia ( / ɪ ˈ s k iː m i ə / ) is from Greek ἴσχαιμος iskhaimos 'staunching blood', from ἴσχω iskhο 'keep back, restrain' and αἷμα haima 'blood'. Infarction Infarction

5616-540: The risk of excessive bleeding. Nevertheless, many clinical practice guidelines continue to recommend aspirin for primary prevention, and some researchers feel that those with very high cardiovascular risk but low risk of bleeding should continue to receive aspirin. Ischemia Ischemia causes not only insufficiency of oxygen, but also reduced availability of nutrients and inadequate removal of metabolic wastes . Ischemia can be partial (poor perfusion ) or total blockage. The inadequate delivery of oxygenated blood to

5694-483: The risk of myocardial infarction, although there is not universal agreement. Dietary modifications are recommended by some national authorities, with recommendations including increasing the intake of wholegrain starch, reducing sugar intake (particularly of refined sugar), consuming five portions of fruit and vegetables daily, consuming two or more portions of fish per week, and consuming 4–5 portions of unsalted nuts , seeds , or legumes per week. The dietary pattern with

5772-409: The skin. Kidney ischemia is a loss of blood flow to the kidney cells. Several physical symptoms include shrinkage of one or both kidneys, renovascular hypertension , acute renal failure , progressive azotemia, and acute pulmonary edema . It is a disease with high mortality rate and high morbidity. Failure to treat could cause chronic kidney disease and a need for renal surgery. Ischemia

5850-850: The start of daylight saving time . Women who use combined oral contraceptive pills have a modestly increased risk of myocardial infarction, especially in the presence of other risk factors. The use of non-steroidal anti inflammatory drugs (NSAIDs), even for as short as a week, increases risk. Endometriosis in women under the age of 40 is an identified risk factor. Air pollution is also an important modifiable risk. Short-term exposure to air pollution such as carbon monoxide , nitrogen dioxide , and sulfur dioxide (but not ozone ) has been associated with MI and other acute cardiovascular events. For sudden cardiac deaths, every increment of 30 units in Pollutant Standards Index correlated with an 8% increased risk of out-of-hospital cardiac arrest on

5928-421: The studies showing these differences had high variability. Females are less likely to report chest pain during a heart attack and more likely to report nausea, jaw pain, neck pain, cough, and fatigue, although these findings are inconsistent across studies. Females with heart attacks also had more indigestion, dizziness , loss of appetite , and loss of consciousness. Shortness of breath is a common, and sometimes

6006-499: The tissues, causing a greater production of free radicals and reactive oxygen species that damage cells. It also brings more calcium ions to the tissues causing further calcium overloading and can result in potentially fatal cardiac arrhythmias and also accelerates cellular self-destruction . The restored blood flow also exaggerates the inflammation response of damaged tissues, causing white blood cells to destroy damaged cells that may otherwise still be viable. Early treatment

6084-527: The wall of the coronary arteries or other arteries, typically over decades, is termed atherosclerosis . Atherosclerosis is characterized by progressive inflammation of the walls of the arteries. Inflammatory cells, particularly macrophages , move into affected arterial walls. Over time, they become laden with cholesterol products, particularly LDL , and become foam cells . A cholesterol core forms as foam cells die. In response to growth factors secreted by macrophages, smooth muscle and other cells move into

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