Cardiac and respiratory responses to exercise in adolescent idiopathic scoliosis

Twenty girls, aged 11-15 years, with adolescent idiopathic scoliosis were studied before spinal fusion was performed. Each underwent a range of lung function tests and a standardised progressive exercise test on a bicycle ergometer. The resting lung function tests showed reduced peak flow rates, lung volumes, and maximum voluntary ventilation. The maximum oxygen uptake was slightly diminished but maximum exercise ventilation was normal. The latter was achieved by using a greater than normal fraction of the vital capacity in tidal breathing while exercising. Mild hyperventilation during submaximal exercise and a trend towards an exercise tachycardia with increasing body weight were observed.