EFFECTS OF SHORT-TERM EXERCISE TRAINING AND ACTIVITY RESTRICTION ON FUNCTIONAL-CAPACITY IN PATIENTS WITH SEVERE CHRONIC CONGESTIVE-HEART-FAILURE

Previous exercise training studies in patients with chronic congestive heart failure (CHF) were performed for periods lasting > 2 months, an d effects of activity restriction on exercise induced-benefits were no t systematically assessed. With one exception study, patients were not reported to be transplant candidates. In this random-order crossover study, effects of 3 weeks of exercise training and 3 weeks of activity restriction on functional capacity in 18 hospitalized patients with s evere CHF [(mean +/- SEM) age 52 +/- 2 years; ejection fraction 21 +/- 1%; half of them on a transplant waiting list] were assessed. The tra ining program consisted of interval exercise with bicycle ergometer (1 5 minutes) 5 times weekly, interval treadmill walking (10 minutes), an d exercises (20 minutes), each 3 times weekly. With training, the onse t of ventilatory threshold was delayed (p <0.001), with increased work rate by 57% (p <0.001) and oxygen uptake by 23.7% (p <0.001). On aver age, there was a 14.6% decrease in slope of ventilation/carbon dioxide production before the onset of ventilatory threshold (p <0.05), and v entilatory equivalent of carbon dioxide production by 10.3% (p <0.01). At the highest comparable work rate (56 +/- 5 W) the following variab les were decreased: heart rare (7.3%; p <0.05), lactate (26.6%; p <0.0 01), and ratings of perceived leg fatigue and dyspnea (14.5% and 16.5% ; p <0.001 each). At peak exercise, oxygen uptake was increased by 19. 7% (p <0.01) and oxygen pulse by 14.2% (p <0.01). There was a correlat ion of baseline peak oxygen uptake and increase of peak oxygen uptake due to training (r = -0.75; p <0.004). Independently of the random ord er, data after activity restriction did not differ significantly from data measured at baseline. Patients with stable, severe CHF con achiev e significant improvements in aerobic and ventilatory capacity and sym ptomology by short-term exercise training using interval exercise meth ods. impairments due to activity restriction suggest the need for long -term exercise training. (C) 1996 by Excerpta Medica, Inc.