Eating disorders (anorexia nervosa and bulimia) are associated with the highest mortality rate of any psychiatric disorder. Much of this mortality and morbidity stem from cardiovascular complications such as arrhythmia related to a prolonged QTc interval and/or electrolyte disorders, hypotension, and bradycardia. Structurally, the heart in patients with eating disorders is atrophic, which may relate to longstanding hypovolemia. These patients have low cardiac output and demonstrate increased peripheral vascular resistance despite the presence of hypotension. The treatment of eating disorders is incremental caloric feeding, which can have its own intrinsic cardiovascular risk (refeeding syndrome) manifested by arrhythmia, tachycardia, congestive heart failure, and sudden cardiac death. Patients will require close monitoring and slower refeedings to minimize the risk of these complications.