Pulmonary Hypertension: Definition, Classification, and Diagnosis

Abstract

Pulmonary hypertension (PH) is a hemodynamic condition characterized by the presence of mean pulmonary artery pressure ≥ 25 mm Hg. Many different baseline conditions and/or risk factors are associated with the development of PH, increasing the complexity for the appropriate diagnosis and classification. Since it was first proposed, PH classification has been adapted to incorporate the increasing knowledge about the disease gathered along the past two decades. Current classification groups together the patients with similar pathophysiological mechanisms, clinical presentation, and management. Nevertheless, correct classification is only possible after a comprehensive diagnostic approach, assessing the most prevalent conditions associated with PH. Most importantly, left ventricular function, lung parenchyma, and the presence of chronic thromboembolic disease have to be evaluated by means of different diagnostic tools. The aim of this review is to summarize the current definitions of PH, which in turn is necessary for determination of the appropriate diagnostic approach.