Characteristics of pulmonary function in patients with pulmonary hypertension

Objective To study the pulmonary function characteristics of patients with pulmonary hypertension (PH).Methods Impulse Oscillmetory system testing (IOS) and pulmonary function testing (PFT) were performed in 51 PH patients (including 30 IPAH patients and 21 CTEPH patients) diagnosed by right heartcatheterization and in 20 healthy control.Results DLCO％pred in IPAH patients was significant lower than that in CTEPH patients (76.60± 19.98 vs 93.62 ± 18.77,P ＜0.01).FEV1 ％ pred,FVC％ pred,FEV1/FVC,MMEF％ pred,MVV％ pred,DLCO ％ pred in PH group were significant lower than those in control group (82.17±16.19 vs 98.38±7.95,88.13±16.64 vs 97.93±9.17,78.66±7.47 vs 84.47±4.58,57.34±16.14 vs 81.18±17.82,83.08±30.41 vs 108.21±27.04,83.61±21.07vs 109.86±15.73,P ＜0.01),Rtot％pred,Z5％pred,R5％pred,R5-R20 (cmH2O · L-1 · s-1),X5,(cmH2O· L-1 · s-1),AX(cmH2O/L),Fres(L/s)in PH group were significant higher than those in control group (131.16±-46.22 vs 90.90± 28.99,146.98 ± 59.22 vs 104.21 ± 19.93,139.57± 53.68 vs 100.10±18.79,1.68±1.52 vs 0.45±0.25,1.37± 1.19 vs 0.89±0.20,12.78± 15.63 vs 5.73±2.49,17.22±5.94 vs 10.33±1.87,P ＜0.01).R5-R20(cmH2O · L-1 · s-1),X5,(cmH2O · L-1 · s-1),AX (cmH2O/L),Fres(L/s) in PH patients with WHO cardiac function level Ⅲ] were significant higher than those inPH patients with cardiac function level Ⅱ (2.28±1.88 vs 1.11±0.73,1.77±1.55 vs 0.98±0.45,18.27±20.47 vs 7.50±5.20,18.92±6.50 vs 15.58±4.93,P ＜0.05)Conclusions The average age of diagnosis in IPAH patients is lower than in CTEPH patients,but the indexes of hemodynamics are more severely impaired.Pulmonary function changes with similar in IPAH patients and in CTEPH patients except for diffuse function.Pulmonary hypertension in patients with mild restrictive and obstructive ventilatory disorder and diffusion dysfunction,airway obstruction mainly consider the peripheral small airway caused,and WHO FC grade is higher,the peripheral small airway obstruction is more serious.To the high-risk population of pulmonary hypertension,regular DLCO monitoring may be helpful in the early detection of pulmonary hypertension. Key words: Idiopathic pulmonary arterial hypertension;  Chronic thromboembolic pulmonary hypertension ;  Pulmonary function testing ;  Impulse oscillmetory system