Pulmonary hypertension and pulmonary arterial hypertension: a clarification is needed.

T he growing interest in pulmonary hypertension (PH) in many medical specialties including cardiology, rheumatology and respiratory medicine, is possibly due to the recent availability of specific drugs approved for a group of rare conditions defined as pulmonary arterial hypertension (PAH). The terms ‘‘pulmonary hypertension’’ and ‘‘pulmonary arterial hypertension’’ appear to be quite similar, and this has led to confusion and ambiguity in both common clinical practice and the medical literature [1]. It is, therefore, important to clarify the different definitions of PH, the relationship between the haemodynamic measurement and the echocardiographic estimate, and the additional diagnostic methods required for the final clinical diagnosis. In addition, it is relevant to highlight the significant role of right heart catheterisation in the diagnostic algorithm of a patient with PH.