Determinants of exercise intolerance in patients with heart failure and reduced or preserved ejection fraction.
This mini-review summarizes the literature regarding the mechanisms of exercise intolerance in patients with heart failure and reduced or preserved ejection fraction (HFREF and HFPEF, respectively). Evidence to date suggests that the reduced peak pulmonary oxygen uptake (pulm V̇o₂) in patients with HFREF compared with healthy controls is due to both central (reduced convective O₂ transport) and peripheral factors (impaired skeletal muscle blood flow, decreased diffusive O₂ transport coupled with abnormal skeletal morphology, and metabolism). Although central and peripheral impairments also limit peak pulm V̇o₂ in HFPEF patients compared with healthy controls, emerging data suggest that the latter may play a relatively greater role in limiting exercise performance in these patients. Unlike HFREF, currently there is limited evidence-based therapies that improve exercise capacity in HFPEF patients, therefore future studies are required to determine whether interventions targeted to improve peripheral vascular and skeletal muscle function result in favorable improvements in peak pulm and leg V̇o2 and their determinants in HFPEF patients.
Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada; mhaykows@gmail.com.
Mark J
MJ
Haykowsky
College of Kinesiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada;
Corey R
CR
Tomczak
Universities Space Research Association, Houston, Texas; and.
Jessica M
JM
Scott
Faculty of Medicine (Division of Cardiology), University of Alberta, Edmonton, Alberta, Canada;
D Ian
DI
Paterson
Department of Internal Medicine, Sections on Cardiology and Geriatrics, Wake Forest University School of Medicine, Winston Salem, North Carolina.
Dalane W
DW
Kitzman
D015444:Exercise / Q000502:physiology*; D017079:Exercise Tolerance / Q000502:physiology*; D006333:Heart Failure / Q000503:physiopathology*; D006801:Humans; D018482:Muscle, Skeletal / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology
exercise physiology; heart failure and preserved ejection fraction; heart failure and reduced ejection fraction