Myocardial Infarction
An Introduction to Myocardial Infarction
Acute myocardial infarction (MI) is one of the leading causes of death in the developed world, and affects three million people a year. All MIs involve a decrease in coronary blood flow, resulting in necrosis of the heart muscle, and are classified as non-ST-segment elevation MI (NSTEMI) or ST-segment elevation MI (STEMI). Prompt diagnosis by 12-lead electrocardiogram and measurement of troponin are essential. Treatment for STEMI requires immediate reperfusion, most often with percutaneous coronary intervention (PCI), though fibrinolysis can be used if immediate PCI is not available. In stable patients, NSTEMI can be managed with antiplatelet agents. Evolving strategies such as intravascular ultrasound (IVUS)-guided PCI, advances in stent technology, and improved antiplatelet therapy have increased survival.