Physical performance of patients with numerous psychosomatic complaints suggestive of hyperventilation

In some patients exercise induces numerous complaints which cannot be attri buted to an organic disorder, and which are suggestive of hyperventilation. The study was designed to investigate in this type of patient: 1) exercise capacity and muscle force; 2) breathing pattern and symptoms during maxima l exercise and recovery; 3) relationships between symptoms and breathing pa ttern. Twenty-four patients mere compared with 20 healthy subjects. They performed a maximal incremental cycle ergometer test and peripheral and respiratory muscle strength were measured. Patients tended to have a decreased exercise capacity and presented with mo derately reduced muscle strength. At comparable minute ventilation, breathi ng frequency was higher (mean: 24 versus 21 per minute) and tidal volume sm aller (mean: 1.42 versus 1.67 L). End-tidal partial pressure of carbon diox ide (PET,CO2) was not significantly different. A significant relation was o bserved between PET,CO2 and respiratory frequency during recovery in patien ts, suggesting a reduced flexibility of the ventilatory response to exercis e. In patients respiratory complaints and paresthesias were weakly correlat ed to PET,CO2 at moderate exercise. It is suggested that the physical deconditioning observed in those patients is rather a consequence than a cause of the response to exercise. The link between symptoms and breathing pattern might be explained by a psychologic al conditioning process.