In brief: Immediate cardiopulmonary resuscitation (CPR) is required to provide a victim of cardiac arrest with artificial ventilation and circulation. The author reviews the basic principles of CPR (establishing an airway, providing ventilation, and initiating cardiac massage) and discusses the underlying dysrhythmias associated with cardiac arrest. Depending on the dysrhythmia involved, appropriate treatment may include electrical therapy (defibrillation) and/or pharmacologic therapy (eg, intravenous epinephrine, lidocaine, bretylium, and sodium bicarbonate).