[Pulmonary function testing in Chinese patients with pulmonary arterial hypertension].

OBJECTIVE

To determine the diagnostic value of pulmonary function testing in Chinese patients with known pulmonary arterial hypertension (PAH) without history of lung/heart valve diseases.

METHODS

Pulmonary function testing was performed in 41 PAH patients diagnosed by right heart catheterization and in 17 healthy controls.

RESULTS

Normal pulmonary function testing results were found in 5 PAH patients (12.2%). Total lung capacity, vital capacity and FEV1 were significantly decreased in PAH patients [(80.27 +/- 11.46)% vs. (94.24 +/- 6.82)%; (79.09 +/- 14.89)% vs. (97.35 +/- 9.51)%; (75.40 +/- 16.58)% vs. (95.12 +/- 12.01)%, respectively, all P < 0.001], the ratio of residual volume/total lung capacity was significantly increased [(117.67 +/- 25.73)% vs. (93.39 +/- 10.87)%, P < 0.001]; FEV1/FVC and maximal expiratory flow of 25% to 75% tended to be lower (-6.0% and -19.4%, P = 0.21 and 0.09) while DLCO and DLCO/VA were significantly decreased by 36.6% and 29.8% (P < 0.001) compared with healthy controls.

CONCLUSIONS

Increased peripheral airway obstruction and normal lung resistance were found in these PAH patients. Normal pulmonary function testing results could not rule out the diagnosis of PAH.