Myocardial infarction: Difference between revisions

{{hatnotedistinguish|People commonly call this condition ''heart attack'', but they may also refer to [[cardiac arrest]] or [[|sudden cardiac death]]}}

| Name = Myocardial infarction

| Image = Heart attack-NIH.gif

| Caption = <center>'''Heart attack'''</center>

| DiseasesDB = 8664

| ICD10 = {{ICD10|I|21||i|20}}-{{ICD10|I|22||i|20}}

| ICD9 = {{ICD9|410}}

| MedlinePlus = 000195

| eMedicineSubj = med

| MeshID = D009203}}

AnA '''acute myocardial infarction''', also and commonly called a '''heart attack''', happens when a [[blood vessel]] in the [[heart]] suddenly becomes blocked. Blood vessels carry [[blood]] and [[oxygen]]. When a blood vessel in the heart gets blocked, blood cannot get to part of the [[heart]]. This part of the heart does not get enough oxygen. This is called [[Ischaemia|ischemia]]. When the heart muscle becomes ischemic (does not get enough blood and oxygen), the ischemia often causes chest pain. This is called [[angina pectoris|Angina Pectoris]]. If the ischemia lasts long enough, the heart muscle that is not getting enough oxygen dies. This is called an [[infarction]]. "[[Myocardium|Myocardial]] infarction" means "infarction (muscle death) in the heart muscle."

A heart attack is a [[medical emergency]]. The first few minutes are very important for keeping the person alive. Some of the damage from the heart attack can be repaired if the person gets treatment duringwithin the first hour of the attack.

Most heart attacks are caused by [[coronary heart disease|coronaryCoronary arteryArtery diseaseDisease]] (CAD). In coronary artery disease, a [[wax]]-like material called [[atheroma|plaque]] builds up on the inside walls of arteries in the heart. This is called [[atherosclerosis]]. Plaque is made of [[cholesterol]] and other [[cell]]s. The amount of plaque increases slowly. As more plaque builds up, the insides of the heart's blood vessels get narrower. This means that less blood can flow through the blood vessels. This can cause [[platelet]]s (which make the [[Clot|blood clot]]) to build up in front of the plaque. This causes a blood clot in the blood vessel. If the clot breaks free and gets stuck in part of the blood vessel made narrower by the plaque, the plaque and the clot together block the blood vessel completely. This makes it impossible for blood to get to part of the heart, and causes a heart attack.

[[File:Heart attack warning signs-women.PNG|thumb|left|<center>'''Heart attack<br>(''myocardial infarction'')<br> Warning signs in women.''</center>]]

[[File:Coronary heart disease.PNG|thumb|'''Coronary heart disease''': Plaque builds up in blood vessels in the heart making them narrow,<br> '''Heart attack:''' here, a blood clot suddenly gets stuck in one of the narrow blood vessels.]]

Signs that a person is having a heart attack show over several minutes, and [[wikt:rare|rare]]ly come immediately. Most people having a heart attack have chest pain. Sometimes, people also have pain in the left [[arm]], the lower [[jaw]], the [[neck]], the right arm, the [[back]], or in parts of the [[abdomen]]. Heart attacks cause increased [[troponin]].

Many women have different symptoms than men. The most common symptoms include [[Dyspnea|shortness of breath]] ([[Dyspnea|trouble breathing]]), weakness, and feeling very [[Fatigue|tired]]. Some women feel tired, do not sleep properly, and have shortness of breath for up to a month before they have a heart attack. Women may also have [[nausea]] and stomach upset when having a heart attack.

Sometimes, people have "silent heart attacks." These are heart attacks that do not cause any pain. They are more common in [[Old age|elderly]] people, women, and people with [[Diabetes mellitus|diabetes]]. In these people, suddenly feeling very tired, or [[Syncope|fainting]], may be the only sign of a heart attack.heart

Doctors or [[paramedic]]s usually start certain treatments as soon as a heart attack is suspected. These treatments include:<ref name=HeartLung>[http://www.nhlbi.nih.gov/health/health-topics/topics/heartattack/treatment How is a heart attack treated?]. National Heart, Lung, and Blood Association. Retrieved November 26, 2015.</ref>

* ''[[Aspirin|''Aspirin]].'']] Aspirin is an early and important treatment for a heart attack. Aspirin keeps platelets from sticking together, and can help prevent more blood clots from forming inside the blood vessels and the heart. Chewing an asprin tablet in the early sages of a heart attack may be helpeful

* ''[[Nitroglycerin]]'' ''(nitro).'' Nitro [[Vasodilation|widens the blood vessels]] in the heart. This makes it easier for blood to flow through those vessels to the heart.

* ''Oxygen (if needed).'' If the patient is having trouble breathing, oxygen can be given.

Once doctors are sure that a person is having a heart attack, there are two main treatments: "clot-busting medicines" ([[Thrombolytic|thrombolytics]]) and percutaneous coronary intervention.<ref name=HeartLung/>

In a percutaneous coronary intervention, a doctor threads a flexible tube into one of the patient's blood vessels, usually one in the upper thigh. The doctor threads the tube up to the blocked blood vessels in the heart. On the end of the tube is a balloon. The doctor blows up the balloon, which pushes the plaque and blood clot against the side of the blocked blood vessel. This allows blood to flow through that blood vessel again. Sometimes, a doctor might also place a small mesh tube called a stent into the blood vessel. The stent will make sure the blood vessel stays open and does not get blocked again in the future.<ref name=Cath>[http://www.heart.org/HEARTORG/Conditions/HeartAttack/SymptomsDiagnosisofHeartAttack/Cardiac-Catheterization_UCM_451486_Article.jsp# Cardiac Catheterization]. American Heart Association. Retrieved November 26, 2015.</ref>

As soon as a person thinks they may be having signs of a heart attack, they should call emergency service right away.<ref name="HeartLung" /> (Emergency services can be reached dialling 911 in the US, and 112 in most of continental Europe) However, the average person waits about three hours before asking for help.<ref name="FirstAid">[httphttps://www.nlm.nih.gov/medlineplus/ency/article/000063.htm Heart attack first aid]. [[MedlinePlus]]. Retrieved December 3, 2006.</ref> When a person waits to get help, they are more likely to have more serious damage to their heart. The American Heart Association says "time is muscle": the more time a person waits to get treatment, the more heart muscle dies.