This study aims to investigate the exercise profile in pulmonary hypertension patients with either pulmonary arterial hypertension, chronic thromboembolic pulmonary hypertension or pulmonary hypertension due to left heart disease and in disease control.

This is a dual-center observational prospective study in patients with pulmonary arterial hypertension, chronic thromboembolic pulmonary hypertension, pulmonary hypertension due to left heart disease. Patients undergoing right heart catheterisation due to dyspnoe with invasive exclusion of pulmonary hypertension will be recruited as disease control.

The study comprises a 1-day screening period, followed by a right heart catheterization with exercise challenge.

The study starts with screening, information of the patients and Informed Consent Form signature at day -1. Screening and inclusion of the patient can be performed on the same day. On the day of the planned right heart catheterization based on clinical grounds, exercise right heart catheterisation (RHC) using Swan-Ganz and/or Conductance catheters with simultaneous echocardiography will be performed. End of study is defined as a complete exercise RHC. Adverse events will be assessed until 1 day after the exercise RHC.

After placement of the Swan-ganz or Conductance catheter patients will undergo an exercise challenge using the following protocol in semi-supine position until exhaustion:

• Incremental workload increase of 20Watt every 2-4 min.
• For patients not able to start a 20 Watt, initial workload can be adjusted to a minimum of 5 Watt with 5 Watt increase every 2-4 min until exhaustion
• Maximal exercise duration is 10-12 minutes
• Symptoms of dyspnoea during exercise will be rated by subjects at baseline, after 6 minutes and at maximum according to the Borg perceived dyspnoea (0-10) scale.

Simultaneously, echocardiography and lung ultrasound will be performed before exercise (baseline), after 6 minutes of exercise and at maximum.

After assessment of right ventriclure pressure-volume loops during maximum exercise, guided by echocardiographic the conductance catheter will be placed in the right atrium to obtain right atrium pressure-volume loops during maximum exercise.

Optional, the exercise RHC will be performed without the Conductance catheter and only with the Swan-Ganz catheter. In this case, pressure values and cardiac output will be measured using the thermodilution method, averaging 3-5 measurements at baseline, 6 minutes and maximum. Detailed assessment of right atrial pressure curves (with a and v wave) will be performed at baseline, 6 minutes and maximum exercise.

Inclusion Criteria:

• Confirmed diagnosis of pulmonary arterial hypertension (World Health Organization group 1)
• Pulmonary hypertension due to left heart disease (World Health Organization group 2)
• Chronic thromboembolic pulmonary hypertension (World Health Organization group 4)
• Invasive exclusion of pulmonary hypertension
• Age ≥ 18 years
• Planned right heart catheterization based on clinical grounds
• Stable specific PAH medications
• Ability to undergo cycle ergometry
• Signed informed consent

Exclusion Criteria:

• Other etiologic groups of pulmonary hypertension (World Health Organization group 3, 5)
• Unstable or severe coronary artery disease
• Uncontrolled arterial hypertension
• Left ventricular ejection fraction < 30%
• Severe congenital or acquired valvular or myocardial disease
• Progressive left heart failure
• History of severe ventricular arrhythmias
• Severe, terminal renal impairment
• Severe obstructive or restrictive lung disease
• Severe lung emphysema or interstitial lung disease

Confirmed diagnosis of either pulmonary arterial hypertension; pulmonary hypertension due to left heat disease; chronic thromboembolic pulmonary hypertension; or invasive exclusion of pulmonary hypertension (control group)

Data will be shared upon request.