PAH is progressive and life-limiting condition making early detection and treatment vital. The symptoms are often and non-specific the condition is often confused for other more common diseases.
This page will explore and investigate the options to diagnose PAH, describing the European Respiratory Society (ERS)/European Society of Cardiology (ESC) diagnostic algorithm and the different investigations that can help diagnosis, including ECHO and right heart catheterisation (RHC).
Early diagnosis of PAH and timely therapeutic intervention is associated with improved patient outcomes. However, early diagnosis of PAH is often challenging due to the non-specific nature of early symptoms, among other factors. See below for detailed guidance on the diagnostic process for PAH.
PAH should be considered in the differential diagnosis of patients presenting with a constellation of exertional dyspnoea, syncope, angina and/or progressive limitation of exercise capacity. This is of particular concern in patients without apparent risk factors or symptoms/signs of common cardiovascular and respiratory disorders.
Special awareness should be directed towards patients with associated conditions and/or risk factors for the development of PAH, including:
• Family history
• Connective tissue disease
• Congenital heart disease
• Human immunodeficiency virus (HIV) infection
• Portal hypertension
• A history of drug or toxin intake known to induce PAH
It is recommended for patients with suspected PAH to undergo further investigation at a specialist centre, including
Adapted from Galiè et al. 2016
ECGs may provide suggestive or supportive evidence of PH by demonstrating right ventricular (RV) hypertrophy, RV strain, right axis deviation, P pulmonale and QTc prolongation.
Chest radiographs may show evidence of right atrial and RV enlargement, as well as pulmonary arterial dilatation. They may also show signs of the underlying disease (e.g. lung disease).
Pulmonary function tests and arterial blood gas samples may help identify the contribution of underlying airway or parenchymal lung disease.
CT imaging can provide information such as pulmonary arterial diameter and clues as to the type of PAH (e.g. cardiac defects, oesophageal dilation in scleroderma). High-resolution CT provides detailed views of the lung parenchyma and facilitates the diagnosis of interstitial lung disease and emphysema.
A V/Q lung scan is used to exclude CTEPH. Where there is evidence of multiple segmental perfusion defects, a diagnosis of CTEPH should be suspected. The final diagnosis of CTEPH requires CT pulmonary angiography, RHC and selective pulmonary angiography.
Learn more about PAH, including its clinical classification and various subtypes.
Find out about the different screening strategies used in at-risk patients. Patients with suspected PAH should be referred to a specialist centre for further investigation.
CT, computed tomography; CTEPH, chronic thromboembolic pulmonary hypertension; DLCO, carbon monoxide diffusing capacity; ECG, electrocardiogram; ERS, European Respiratory Society; ESC, European Society of Cardiology; HIV, human immunodeficiency virus; HPAH, heritable pulmonary arterial hypertension; HRCT, high-resolution computed tomography; mPAP, mean pulmonary arterial pressure; PA, pulmonary artery; PAH, pulmonary arterial hypertension; PAWP, pulmonary arterial wedge pressure; PFT, pulmonary function test; PH, pulmonary hypertension; PVR, pulmonary vascular resistance; RHC, right heart catheterisation; RV, right ventricular; TRV, tricuspid regurgitation velocity; V/Q, ventilation/perfusion