Healthy and HF subjects (ejection fraction <45%, stable conditions) underwent cardiopulmonary exercise test. All of them, carrying a wearable metabolic cart, performed a 6-minute walking test, two 4-minute treadmill exercises (at 2 and 3 km/h), and ADLs: ADL1 (getting dressed), ADL2 (folding 8 towels), ADL3 (putting away 6 bottles), ADL4 (making a bed), ADL5 (sweeping the floor for 4 minutes), ADL6 (climbing 1 flight of stairs carrying a load).
Sixty patients with HF (age 65.2±12.1 years; ejection fraction 30.4±6.7%, peakVO 14.2±4.0 mL/[min·kg]) and 40 healthy volunteers (58.9±8.2 years, peakVO 28.1±7.4 mL/[min·kg]) were enrolled. For each exercise, patients showed higher VE/VCO ratio, percentage of peakVO, and Borg scale value than controls, while absolute values of task oxygen uptake and exercise duration were lower and higher, respectively, in all activities, except for treadmill (fixed execution time and intensity). Differently from Borg Scale data, metabolic values and exercise time length changed in parallel with HF severity, except for ADL duration in very short (ADL3) and composite (ADL1) activities. Borg scale values correlated with percentage of peakVO.
During ADLs, patients self-regulated activities in parallel with HF severity by decreasing intensity (VO) and prolonging the effort.