Acute myocardial infarction (AMI) is one of the leading causes of death in the developed world. The prevalence of the disease approaches 3 million people worldwide, with more than 1 million deaths in the United States annually. AMI can be divided into 2 categories: non–ST-segment elevation myocardial infarction (NSTEMI) and ST-segment elevation myocardial infarction (STEMI). Unstable angina resembles an NSTEMI, but normal cardiac markers distinguish it.
Myocardial infarction (MI) causes permanent damage to the heart muscle due to inadequate oxygen supply. MI can impair diastolic and systolic function, increasing the risk of arrhythmias. Additionally, an MI can lead to various serious complications. Prompt reperfusion and restoration of blood flow to the heart are crucial. Early treatment within 6 hours of symptom onset significantly improves prognosis.
An MI is diagnosed when 2 of the following criteria are met:
Symptoms of ischemia
New ST-segment changes or a left bundle branch block (LBBB)
Presence of pathological Q waves on electrocardiogram (ECG)
New regional wall motion abnormality on imaging study
Presence of an intracoronary thrombus at autopsy or angiography
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