Defining the System-Contributors to exercise Limitations in Heart Failure

One of the primary hallmarks of patients diagnosed with heart failure (HF), from all etiologies, is a reduced tolerance to exercise and compromised functional capacity. The physiological contributors of this limitation stems from poor pumping capacity but also major changes in functioning of the vasculature, skeletal muscle, and respiratory systems. There is a major body of literature that supports the relevance of each of these systems to our understanding of exercise intolerance during HF. While the literature has not yet identified the primary contributor to exercise intolerance in the context of HF, advances in our understanding of the central and peripheral mechanisms of exercise intolerance during HF (with preserved and reduced ejection fraction) are critical for the future design of therapeutic modalities that will improve this outcome. The interrelatedness between systems cannot be discounted. Therefore, the current review summarizes the current body of literature related to the pathophysiology of HF contributing to poor exercise tolerance and potential mechanisms involved.