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ST-elevation myocardial infarction: Difference between revisions
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An '''ST-elevation myocardial infarction''' (STEMI) is a clinical form of [[acute myocardial infarction]] and one form of [[acute coronary syndrome]]. It is defined as the presence of ischaemic symptoms, ST-elevations in a pattern consistent with the blood supply of one coronary artery and a rise and/or fall in [[troponin]] levels. Ischaemic symptoms are classically [[Chest pain|angina]], but may also be dyspnoea, nausea, sweating, anxiety, or non-anginal chest pain. For initial evaluation, see [[acute coronary syndrome]]. | <section begin="A&IC" />An '''ST-elevation myocardial infarction''' (STEMI) is a clinical form of [[acute myocardial infarction]] and one form of [[acute coronary syndrome]]. It is defined as the presence of ischaemic symptoms, ST-elevations in a pattern consistent with the blood supply of one coronary artery and a rise and/or fall in [[troponin]] levels. Ischaemic symptoms are classically [[Chest pain|angina]], but may also be dyspnoea, nausea, sweating, anxiety, or non-anginal chest pain. <section end="A&IC" />For initial evaluation, see [[acute coronary syndrome]]. | ||
STEMI must be immediately transferred to a [[Percutaneous intervention|PCI]] centre for treatment. | STEMI must be immediately transferred to a [[Percutaneous intervention|PCI]] centre for treatment. | ||
<section begin="A&IC" /> | |||
== Diagnosis and evaluation == | == Diagnosis and evaluation == | ||
If a patient has typical chest pain and the ECG shows ST-elevations in a pattern consistent with the blood supply of one coronary artery, we do not waste time with a troponin test, as the probability that it is a STEMI is high. However, in many cases a blood test can be performed in the ambulance, thereby not delaying the time to <abbr>PCI</abbr>. | If a patient has typical chest pain and the ECG shows ST-elevations in a pattern consistent with the blood supply of one coronary artery, we do not waste time with a troponin test, as the probability that it is a STEMI is high. However, in many cases a blood test can be performed in the ambulance, thereby not delaying the time to <abbr>PCI</abbr>. | ||
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ST-elevation or depression in the inferior leads (II, III, aVF) suggests inferior wall infarct. In these cases, the right-sided leads V4R, V5R, and V6R should be obtained to assess for a possible right ventricular infarct. In this case, ST-elevation would be present in leads V4R – V6R. | ST-elevation or depression in the inferior leads (II, III, aVF) suggests inferior wall infarct. In these cases, the right-sided leads V4R, V5R, and V6R should be obtained to assess for a possible right ventricular infarct. In this case, ST-elevation would be present in leads V4R – V6R. | ||
<section end="A&IC" /> | |||
ST-elevations can be present in other conditions which may present similarly, like [[pericarditis]], [[myocarditis]], [[left ventricular hypertrophy]], etc. Care must be used in ambiguous cases, but it’s often better to perform a PCI to be safe. | ST-elevations can be present in other conditions which may present similarly, like [[pericarditis]], [[myocarditis]], [[left ventricular hypertrophy]], etc. Care must be used in ambiguous cases, but it’s often better to perform a PCI to be safe. | ||
== Pathomechanism == | == Pathomechanism == | ||
See [[acute myocardial infarction]]. | See [[acute myocardial infarction]]. | ||
<section begin="A&IC" /> | |||
== Initial management == | == Initial management == | ||
If the expected time to a PCI lab is < 120 minutes, the patient is rushed straight there, with as low time from symptom onset to catheter insertion as possible. If the expected time is > 120 minutes, the patient should receive [[thrombolysis]] and then be rushed to a PCI lab. | If the expected time to a PCI lab is < 120 minutes, the patient is rushed straight there, with as low time from symptom onset to catheter insertion as possible. If the expected time is > 120 minutes, the patient should receive [[thrombolysis]] and then be rushed to a PCI lab. | ||
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In the ambulance, [[Aspirin]] (300 mg) should be administered to all patients to be chewed and swallowed in all cases of STEMI. In addition to this, a loading dose of a [[P2Y12 inhibitor]] like clopidogrel (Plavix®) or ticagrelor should be administered. [[Unfractionated heparin]] (<abbr>UFH</abbr>) is administered to all patients unless they’re already anticoagulated. | In the ambulance, [[Aspirin]] (300 mg) should be administered to all patients to be chewed and swallowed in all cases of STEMI. In addition to this, a loading dose of a [[P2Y12 inhibitor]] like clopidogrel (Plavix®) or ticagrelor should be administered. [[Unfractionated heparin]] (<abbr>UFH</abbr>) is administered to all patients unless they’re already anticoagulated. | ||
<section end="A&IC" /> | |||
Following entry to the hospital, the following two medications may be considered. They are secondary prophylaxis but can usually be started the same day or the day after: | Following entry to the hospital, the following two medications may be considered. They are secondary prophylaxis but can usually be started the same day or the day after: | ||
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High intensity statin ([[Atorvastatin]] 40-80 mg or [[rosuvastatin]] 20-40 mg) should be administered to all patients as soon as possible. | High intensity statin ([[Atorvastatin]] 40-80 mg or [[rosuvastatin]] 20-40 mg) should be administered to all patients as soon as possible. | ||
<section begin="A&IC" /> | |||
If the anatomy is unsuitable for PCI and the infarcted myocardial area is large, or there is cardiogenic shock, emergency [[coronary artery bypass surgery]] (<abbr>CABG</abbr>) should be performed. | If the anatomy is unsuitable for PCI and the infarcted myocardial area is large, or there is cardiogenic shock, emergency [[coronary artery bypass surgery]] (<abbr>CABG</abbr>) should be performed.<section end="A&IC" /> | ||
Summary: | Summary: | ||