title: The importance of daily physical activity for improved exercise tolerance in heart failure patients with limited access to centre-based cardiac rehabilitation.
abstract: BACKGROUND
  Supervised cardiac rehabilitation provided at dedicated centres ameliorates exercise intolerance in patients with chronic heart failure.
  
  
  OBJECTIVE
  To correlate the amount of physical activity outside the hospital with improved exercise tolerance in patients with limited access to centre-based programs.
  
  
  METHODS
  Forty patients (median age 69 years) with stable heart failure due to systolic left ventricular dysfunction participated in cardiac rehabilitation once per week for five months. Using a validated single-axial accelerometer, the number of steps and physical activity-related energy expenditures on nonrehabilitation days were determined.
  
  
  RESULTS
  Median (interquartile range) peak oxygen consumption was increased from 14.4 mL/kg/min (range 12.9 mL/kg/min to 17.8 mL/kg/min) to 16.4 mL/kg/min (range 13.9 mL/kg/min to 19.1 mL/kg/min); P<0.0001, in association with a decreased slope of the minute ventilation to carbon dioxide production plot (34.2 [range 31.3 to 38.1] versus 32.7 [range 30.3 to 36.5]; P<0.0001). Changes in peak oxygen consumption were correlated with the daily number of steps (P<0.01) and physical activity-related energy expenditures (P<0.05). Furthermore, these changes were significantly correlated with total exercise time per day and time spent for light (≤3 metabolic equivalents) exercise, but not with time spent for moderate/vigorous (>3 metabolic equivalents) exercise.
  
  
  CONCLUSIONS
  The number of steps and energy expenditures outside the hospital were correlated with improved exercise capacity. An accelerometer may be useful for guiding home-based cardiac rehabilitation.
authors.affiliation: Department of Rehabilitation;
authors.forename: Noriaki
authors.initials: N
authors.lastname: Sato
authors.forename: Hideki
authors.initials: H
authors.lastname: Origuchi
authors.forename: Umpei
authors.initials: U
authors.lastname: Yamamoto
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takanaga
authors.forename: Masahiro
authors.initials: M
authors.lastname: Mohri
keywords: Accelerometer; Cardiac rehabilitation; Heart failure