Acute coronary syndrome (ACS) is a major health care and economic burden in the United States and accounts for more than 1 million hospitalizations annually. The morbidity and mortality due to ACS are substantial—nearly half of all deaths due to coronary heart disease occur following an ACS. This review provides an up-to-date summary of the pathophysiology, diagnosis, and treatment of ACS. We also provide an overview of the management of common hemodynamic disturbances and myocardial infarction complications that physicians often encounter in an intensive care setting.