Dyspnea is a major symptom in pulmonary arterial hypertension and people with the same haemodynamic have generally different degree of dyspnea in pulmonary arterial hypertension. The hyperventilation syndrome is a frequent cause of dyspnea in general population and in respiratory diseases like asthma but has never been studied in pulmonary hypertension. The goal of this study is to measure the prevalence of pulmonary hypertension in a population of patients with controlled pulmonary arterial hypertension (PAH).

Hyperventilation syndrome has been described as a cause of dyspnea in the general population and in several chronic respiratory diseases such as asthma with 20 to 40% of asthmatics affected. However, Hyperventilation syndrome has never been sought in a population with PAH. Hyperventilation syndrome, although complex pathophysiology, may be simply corrected by a management of respiratory physiotherapy based on the control of respiration.

Inclusion Criteria:

• Non smoker or tobacco stopped for minimum 2 years ans maximum 10 year-pack. - Idiopathic, heritable, related to drug or toxics, associated with controlled pulmonary hypertension. Diagnosis and treatment of pulmonary hypertension for more than 4 months.
• Optimal control of pulmonary hypertension (no right heart failure symptom and NTproBNP < 300ng/L or Brain Natriuretic Peptide(BNP) < 50 ng/L and optimal hemodynamic results measured by a right heart catheterization in the last year: right atrial pressure < 8 mmHg, cardiac index > 2,5 L/min/m2, veinous saturation in oxygen > 65%)
• Informed and written consent
• Non-affiliation to a social security

Exclusion Criteria:

• Existence of another form of pulmonary hypertension
• Existence of vocal cord dysfunction
• Pregnancy
• Obesity> stage 2 (BMI 35 kg / m2)
• Age ≥ 75 years