Acute coronary syndromes (ACS), and specifically myocardial infarction (MI), are a major cause of morbidity and mortality in the intensive care unit. Type 1 MI is most often caused by transient or prolonged occlusion of an epicardial coronary artery. Type 2 MI is caused by an imbalance between myocardial supply and demand in the absence of an acute coronary occlusion and is frequently precipitated by other critical illness, such as sepsis, trauma, acute anemia, severe hypertension, and others. Both result in myocardial injury due to tissue ischemia. Bedside echocardiography is an essential tool in triaging the critically ill patient with chest pain. Ischemia or infarction can be diagnosed in the proper clinical context when a pattern of abnormal myocardial wall motion is seen in a typical vascular territory of an epicardial coronary artery. Acute deterioration of a patient with MI in the ICU may be caused by mechanical complications, which are also most efficiently diagnosed with bedside ultrasound. Formal echocardiography should be incorporated along with bedside echocardiography into the evaluation of a patient with diagnosed or suspected acute coronary syndrome for advanced chamber, valvular, and hemodynamic assessment.