PULMONARY-FUNCTION AND SYMPTOM-LIMITED EXERCISE STRESS-TESTING IN SUBJECTS WITH LATE SEQUELAE OF POLIOMYELITIS

Sixty-eight subjects, consecutively admitted to our rehabilitation hos pital with a presumptive postpolio syndrome, were examined by pulmonar y function and symptom-limited exercise stress testing. The purpose of this investigation was to study how many of these subjects could be c lassified as suffering from cardiorespiratory deconditioning. The subj ects had moderately reduced lung function of restrictive type, and non e of the subjects had forced expiratory volume for one second (FEV1) b elow 30% of predicted value, indicating that hypoventilation would pro bably not occur. A pronounced reduction in maximal oxygen uptake (max VO2) was seen, especially in women. The maximal heart rate (max HR) va lues were above 70% of predicted values in all but one subject, indica ting that the subjects might benefit from endurance training. Fifteen subjects had a suspected pulmonary limitation due to the exercise, wit h the ratio ventilation/maximal voluntary ventilation (V/MVV) above 70 %. However, max HR in these subjects did not differ from that in the s ubjects 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 a nd/or capillary lactate concentration > 4 mmol/l during exercise, indi cating that muscular factors limited the exercise. These results indic ate that cardiorespiratory deconditioning was considerable in most of our subjects with postpolio syndrome.