Purpose: This study compares the responses of 20 male patients (mean age 51 +/- 11 years) with stable heart failure during peak and submaximal arm and leg exercise.
Methods: On day 1, subjects completed two symptom-limited graded exercise tests, one with their arms and one with their legs. On day 2, subjects performed arm only and leg only exercise at a matched power output of 30 Watts (W). Ten age-matched healthy subjects served as controls.
Results: During peak arm exercise power output, oxygen consumption (VO2), ventilation, and rate-pressure product were higher in healthy subjects than in patients with heart failure. However, when a subject's peak VO2 or power output during arm exercise was expressed as a percentage of that achieved during peak leg exercise, no significant differences were noted between patients with heart failure and healthy subjects. Among both groups, rate-pressure product, VO2, ventilation, the ventilatory equivalent for O2, and respiratory exchange ratio were all higher when exercising at 30 W with the arms versus 30 W with the legs. Also, in patients with heart failure heart rate was higher (+6 min-1) and stroke volume index lower (-4 mL/m2) during submaximal arm than leg exercise.
Conclusions: Although peak exercise capacity (Watts, VO2) during arm exercise is lower in patients with heart failure than healthy subjects, when expressed as a percentage of peak leg capacity, the extent of the exercise intolerance they experience during arm exercise does not differ from healthy subjects.