Critical care cardiology refers to the practice focus of and subspecialty training for the comprehensive management of life-threatening cardiovascular diseases and comorbid conditions that require advanced critical care in an intensive care unit. The development of coronary care units is often credited for a dramatic decline in mortality rates after acute myocardial infarction throughout the 1960s. As the underlying patient population became progressively sicker, changes in organizational structure, staffing, care delivery, and training paradigms lagged. The coronary care unit gradually evolved from a focus on rapid resuscitation from ventricular arrhythmias in acute myocardial infarction into a comprehensive cardiac intensive care unit designed to care for the sickest patients with cardiovascular disease. Over the past decade, the cardiac intensive care unit has continued to transform with an aging population, increased clinical acuity, burgeoning cardiac and noncardiac comorbidities,