Acute myocardial infarction (AMI or MI), more commonly known as a heart attack, is a medical condition that occurs when the to a part of the is interrupted, most commonly due to rupture of a . The resulting or , if left untreated for a sufficient period, can cause damage and/or death of heart tissue. It is a , and the leading cause of death for both men and women all over the world. Important are a history of vascular disease such as and/or , a previous heart attack or , any previous episodes of or , older age—especially men over 40 and women over 50, , excessive alcohol consumption, the abuse of certain drugs, high triglyceride levels, high (low-density lipoprotein, "bad cholesterol") and low (high density lipoprotein, "good cholesterol"), , , , and chronic high stress levels. and a history of are also significant risk factors which may indicate a hightened disposition towards suffering a MI.
The term myocardial infarction is derived from (the heart muscle) and (tissue death due to oxygen starvation). The phrase "heart attack" is sometimes used incorrectly to describe , which may or may not be the result of acute myocardial infarction. A heart attack is different from, but can be the cause of , which is the stopping of the heartbeat, and , an abnormal heartbeat. It is also distinct from , in which the pumping action of the heart is impaired; severe myocardial infarction may lead to heart failure, but not necessarily.
Classical symptoms of acute myocardial infarction include (typically radiating to the left arm or left side of the neck), , , , , , and (often described as a sense of impending doom). Patients frequently feel suddenly ill. Women may experience less typical symptoms than men. The most common symptoms of MI in women include shortness of breath, weakness, a feeling of indigestion, and . Approximately one fourth of all myocardial infarctions are silent, without chest pain or other symptoms. A history of diabetes should heighten the index of suspicion, particularly if the patient has (diabetes-related nerve damage).
Immediate treatment for suspected acute myocardial infarction includes , , and sublingual (colloquially referred to as and abbreviated as NTG or GTN). is also often given, classically .
The patient will receive a number of diagnostic tests, such as an (ECG, EKG), a chest and to detect elevations in the -MB (CK-MB) fraction or in I (TnI) or T (TnT) levels (these are chemical markers specific to the myocardium and are often referred to as ). On the basis of the ECG, a distinction is made between ST elevation MI (STEMI) or non-ST elevation MI (NSTEMI). Most cases of STEMI are treated with or if possible with (PCI, angioplasty and stent insertion), provided the hospital has facilities for . NSTEMI is managed with medication, although PCI is often performed during hospital admission. In patients who have multiple blockages and who are relatively stable, or in a few extraordinary emergency cases, of the blocked coronary artery performed by a cardiothoracic surgeon is an option. Once admitted to hospital, the patient is observed on a , as the incidence of or in the case of MI is high. In cases where the patient is unstable, more intensive nursing care may be warranted.