Diagnosis and treatment of pulmonary hypertension

### Learning objectives Pulmonary hypertension (PH) is a descriptive name for abnormally elevated pressures in the pulmonary vasculature. PH has been defined as a mean pulmonary arterial pressure (mPAP) ≥25 mm Hg at rest, measured by right heart catheterisation (RHC).1 It can be caused by an increase in pulmonary vascular resistance (PVR), pulmonary blood flow, pulmonary venous pressure or a combination of these factors. PH leads to right ventricular (RV) overload and finally RV failure and death.2 Commonly, PH is diagnosed at a late stage of the disease, and is associated with poor survival.3 This underscores the importance of early recognition and treatment of PH in order to improve the outcome in this patient population.4 PH is characterised by different pathological lesions in the pulmonary vasculature, depending on the underlying cause. The 5th World Symposium on Pulmonary Hypertension in Nice in 2013 classified PH according to these underlying aetiologies, creating five groups: (1) pulmonary arterial hypertension (PAH); (2) PH due to left sided disease; (3) PH due to lung disease; (4) chronic thromboembolic PH (CTEPH); (5) PH with unclear or multifactorial mechanisms (box 1).5 ### Box 1 Clinical classification of pulmonary hypertension5 1 Pulmonary arterial hypertension (PAH) 1′ Pulmonary veno-occlusive disease and/or pulmonary capillary haemangiomatosis 1″ Persistent pulmonary hypertension of the newborn 2 Pulmonary hypertension (PH) due to left heart disease 3 PH …