<Tr> <Th> Prognosis </Th> <Td> STEMI 10% risk of death (developed world) </Td> </Tr> <Tr> <Th> Frequency </Th> <Td> 15.9 million (2015) </Td> </Tr> <P> 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 . The most common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck, or jaw . Often it occurs in the center or left side of the chest and lasts for more than a few minutes . The discomfort may occasionally feel like heartburn . Other symptoms may include shortness of breath, nausea, feeling faint, a cold sweat, or feeling tired . About 30% of people have atypical symptoms . Women more often have atypical symptoms than men . 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 . </P> <P> 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, among others . The complete blockage of 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, and extreme cold, among others . A number of tests are useful to help with diagnosis, including electrocardiograms (ECGs), blood tests, and coronary angiography . An ECG, which 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 . </P>

St segment elevation myocardial infarction signs and symptoms