Pulmonary function and symptom-limited exercise stress testing in subjects with late sequelae of poliomyelitis

Sixty-eight subjects, consecutively admitted to our rehabilitation hospital with a presumptive postpolio syndrome, were examined by pulmonary function and symptom-limited exercise stress testing. The purpose of this investigation was to study how many of these subjects could be classified as suffering from cardiorespiratory deconditioning. The subjects had moderately reduced lung function of restrictive type, and none of the subjects had forced expiratory volume for one second (FEV1) below 30% of predicted value, indicating that hypoventilation would probably not occur. A pronounced reduction in maximal oxygen uptake (max VO2) was seen, especially in women. The maximal heart rate (max HR) values were above 70% of predicted values in all but one subject, indicating that the subjects might benefit from endurance training. Fifteen subjects had a suspected pulmonary limitation due to the exercise, with the ratio ventilation/maximal voluntary ventilation (V/MVV) above 70%. However, max HR in these subjects did not differ from that in the subjects with the ratio V/MVV below 70%. Thirteen other subjects had a ratio V/MVV < 70% but did not achieve respiratory quotient (R) > 1.0 and/or capillary lactate concentration > 4 mmol/l during exercise, indicating that muscular factors limited the exercise. These results indicate that cardiorespiratory deconditioning was considerable in most of our subjects with postpolio syndrome.