Chronotropic Incompetence

C hronotropic incompetence (CI), broadly defined as the inability of the heart to increase its rate commensurate with increased activity or demand, is common in patients with cardiovascular disease, produces exercise intolerance that impairs quality of life, and is an independent predictor of major adverse cardiovascular events and overall mortality.However, the importance of CI is underappreciated, and CI is often overlooked in clinical practice.This may be due in part to multiple definitions, the confounding effects of aging and medications, and the need for formal exercise testing for definitive diagnosis.This review discusses the definition, mechanisms, diagnosis, and treatment of CI, with particular…