Category Archives: Myocardial Infarction

Clinical Relevance of Anterior Myocardial Infarction Anterior STEMI results from occlusion of the left anterior descending artery (LAD). Anterior myocardial infarction carries the worst prognosis of all infarct locations, mostly due to larger infarct size. Continue reading →

Identifying an acute myocardial infarction on the 12-lead ECG is the most important thing you can learn in ECG interpretation. Continue reading →

Half the deaths from a heart attack occur in the first 3 or 4 hours after symptoms begin. It is crucial that symptoms of a heart attack be treated as a medical emergency. Continue reading →

A syndrome of prolonged, severe chest pain was first described in medical literature in 1912 by James Bryan Herrick, who attributed the syndrome to coronary thrombosis, the development of a clot in a major blood vessel serving the heart. As a result, the disorder was termed coronary thrombosis or coronary occlusion (blockage of a coronary artery). Later evidence indicated, however, that, though thrombotic occlusion of an atheromatous lesion in a coronary artery is the most common cause of the disorder, the manifestations are the result of the death of an area of heart muscle (infarction). Continue reading →

Pathophysiology Cardiac muscle tissue death from lack of blood flow. The blood carries oxygen and nutrients to the cells. When this is decreased, cells die also called necrosis. Continue reading →

Myocardial infarctionSynonymsAcute myocardial infarction (AMI), heart attackDiagram showing the blood supply to the heart by the two major blood vessels, the left and right coronary arteries (labelled LCA and RCA). A myocardial infarction (2) has occurred with blockage of a branch of the left coronary artery (1).SpecialtyCardiologySymptomsChest pain, shortness of breath, nausea, feeling faint, cold sweat, feeling tired, arm pain, jaw pain, stomach pain[1][2]ComplicationsHeart failure, irregular heartbeat, cardiogenic shock, cardiac arrest[3][4]CausesUsually coronary artery disease[3]Risk factorsHigh blood pressure, smoking, diabetes, lack of exercise, obesity, high blood cholesterol[5][6]Diagnostic methodElectrocardiograms (ECGs), blood tests, coronary angiography[7]TreatmentPercutaneous coronary intervention, thrombolysis[8]MedicationAspirin, nitroglycerin, heparin[8][9]PrognosisSTEMI 10% risk of death (developed world)[8]Frequency15.9 million (2015)[10] Myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to a part of the heart, causing damage to the heart muscle.[1] The most common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck, or jaw.[1] Often it occurs in the center or left side of the chest and lasts for more than a few minutes.[1] The discomfort may occasionally feel like heartburn.[1] Other symptoms may include shortness of breath, nausea, feeling faint, a cold sweat, or feeling tired.[1] About 30% of people have atypical symptoms.[8] Women more often present without chest pain and instead have neck pain, arm pain, or feel tired.[11] Among those over 75 years old, about 5% have had an MI with little or no history of symptoms.[12] An MI may cause heart failure, an irregular heartbeat, cardiogenic shock, or cardiac arrest.[3][4] Most MIs occur due to coronary artery disease.[3] Risk factors include high blood pressure, smoking, diabetes, lack of exercise, obesity, high blood cholesterol, poor diet, and excessive alcohol intake, among others.[5][6] The complete blockage of a coronary artery caused by a rupture of an atherosclerotic plaque is usually the underlying mechanism of an MI.[3] MIs are less commonly caused by coronary artery spasms, which may be due to cocaine, significant emotional stress, and extreme cold, among others.[13][14] A number of tests are useful to help with diagnosis, including electrocardiograms (ECGs), blood tests, and coronary angiography.[7] An ECG, which is a recording of the heart's electrical activity, may confirm an ST elevation MI (STEMI) if ST elevation is present.[8][15] Commonly used blood tests include troponin and less often creatine kinase MB.[7] Treatment of an MI is time-critical.[16] Aspirin is an appropriate immediate treatment for a suspected MI.[9] Nitroglycerin or opioids may be used to help with chest pain; however, they do not improve overall outcomes.[8][9] Supplemental oxygen is recommended in those with low oxygen levels or shortness of breath.[9] 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.[8] People who have a non-ST elevation myocardial infarction (NSTEMI) are often managed with the blood thinner heparin, with the additional use of PCI in those at high risk.[9] In people with blockages of multiple coronary arteries and diabetes, coronary artery bypass surgery (CABG) may be recommended rather than angioplasty.[17] After an MI, lifestyle modifications, along with long term treatment with aspirin, beta blockers, and statins, are typically recommended.[8] Worldwide, about 15.9 million myocardial infarctions occurred in 2015.[10] More than 3 million people had an ST elevation MI and more than 4 million had an NSTEMI.[18] STEMIs occur about twice as often in men as women.[19] About one million people have an MI each year in the United States.[3] In the developed world the risk of death in those who have had an STEMI is about 10%.[8] Rates of MI for a given age have decreased globally between 1990 and 2010.[20] In 2011, a 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.[21] Myocardial infarction (MI) refers to tissue death (infarction) of the heart muscle (myocardium) Continue reading →

[Guideline] Amsterdam EA, Wenger NK, Brindis RG, Casey DE Jr, Ganiats TG, Holmes DR Jr, et al. Continue reading →

What is Ischemic Heart Disease? Continue reading →

Abstract VOL: 99, ISSUE: 04, PAGE NO: 28 Julia Hubbard, MSc, BSc, PGDE, DipN, RGN, is adult branch leader, School of Nursing and Midwifery, University of East Anglia For most people this occurs suddenly and is due to the rupture of an atheromatous plaque and the formation of a thrombus within the coronary circulation. Less common causes of MI include vasospasm of a coronary artery, which causes temporary occlusion of the artery lumen, or a sudden increase in oxygen demand such as a sustained rapid cardiac dysrhythmia (Julian et al, 1998). Continue reading →

Diagnosing an acute myocardial infarction by ECG is an important skill for healthcare professionals, mostly because of the stakes involved for the patient. One of the complications with using ECG for myocardial infarction diagnosis is that it is sometimes difficult to determine which changes are new and which are old. For the purposes of this learning module, we will assume that all changes are new for the patient and thus represent an acute myocardial infarction. Continue reading →