Suppression of cerebral hemodynamics is associated with reduced functional capacity in patients with heart failure

Am J Physiol Heart Circ Physiol. 2011 Apr;300(4):H1545-55. doi: 10.1152/ajpheart.00867.2010. Epub 2011 Jan 28.


This investigation elucidated the underlying mechanisms of functional impairments in patients with heart failure (HF) by simultaneously comparing cardiac-cerebral-muscle hemodynamic and ventilatory responses to exercise among HF patients with various functional capacities. One hundred one patients with HF [New York Heart Association HF functional class II (HF-II, n = 53) and functional class III (HF-III, n = 48) patients] and 71 normal subjects [older control (O-C, n = 39) and younger control (Y-C, n = 32) adults] performed an incremental exercise test using a bicycle ergometer. A recently developed noninvasive bioreactance device was adopted to measure cardiac hemodynamics, and near-infrared spectroscopy was employed to assess perfusions in the frontal cerebral lobe (Δ[THb](FC)) and vastus lateralis muscle (Δ[THb](VL)). The results demonstrated that the Y-C group had higher levels of cardiac output, Δ[THb](FC), and Δ[THb](VL) during exercise than the O-C group. Moreover, these cardiac/peripheral hemodynamic responses to exercise in HF-III group were smaller than those in both HF-II and O-C groups. Although the change of cardiac output caused by exercise was normalized, the amounts of blood distributed to frontal cerebral lobe and vastus lateralis muscle in the HF-III group significantly declined during exercise. The HF-III patients had lower oxygen-uptake efficiency slopes (OUES) and greater Ve-Vo(2) slopes than the HF-II patients and age-matched controls. However, neither hemodynamic nor ventilatory response to exercise differed significantly between the HF-II and O-C groups. Cardiac output, Δ[THb](FC), and Δ[THb](VL) during exercise were directly related to the OUES and Vo(2peak) and inversely related to the Ve-Vco(2) slope. Moreover, cardiac output or Δ[THb](FC) was an effect modifier, which modulated the correlation status between Δ[THb](VL) and Ve-Vco(2) slope. We concluded that the suppression of cerebral/muscle hemodynamics during exercise is associated with ventilatory abnormality, which reduces functional capacity in patients with HF.

Publication types

  • Controlled Clinical Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Carbon Dioxide / blood
  • Cardiac Output / physiology
  • Cerebral Cortex / blood supply*
  • Cerebral Cortex / physiopathology
  • Cognition Disorders / etiology*
  • Cognition Disorders / physiopathology
  • Exercise / physiology
  • Exercise Test
  • Female
  • Heart Failure / complications*
  • Heart Failure / physiopathology
  • Hemodynamics / physiology
  • Humans
  • Male
  • Middle Aged
  • Oxygen / blood
  • Oxygen Consumption / physiology
  • Pulmonary Ventilation / physiology
  • Regional Blood Flow / physiology*


  • Carbon Dioxide
  • Oxygen