Pathophysiology of exercise capacity after heart transplantation

Abstract

Heart transplantation is a life-saving treatment option for patients with end-stage heart failure. The improvement in exercise capacity of patients can vary to a great extent following transplant surgery. This review outlines the pathophysiology behind the changes in exercise capacity after heart transplantation. Reasons for exercise intolerance can be classified as central (cardiac) and peripheral (vascular and skeletal muscle). Cardiac mechanisms that limit exercise capacity are chronotropic incompetence due to denervation of the heart and diastolic dysfunction. Peripheral mechanisms are endothelial dysfunction and morphological alterations in the skeletal muscle. Some of the pathophysiological changes can be recovered with exercise therapy after the transplantation surgery. Research should be directed to reveal the safest and most effective exercise prescription to heart transplant recipients, targeting all of the mechanisms that contribute to exercise intolerance in a holistic approach.