Pulmonary Arterial Hypertension: An Overview

Pulmonary hypertension (PH) is a hemodynamic state defined by a resting mean pulmonary artery pressure (PAP) at or above 25 mm Hg.[1] with normal left ventricular filling pressure (mean pulmonary wedge pressure) 15 mmHg or less. Pre-capillary PH is defined as mean PAP ≥25 mm Hg in association with PAOP ≤15 mm Hg and a pulmonary vascular resistance (PVR) >3 Wood units. This include group 1, 3, 4 and 5 (Table 1). [2] Post-capillary PH (group 2 as shown in Table 1) is characterized by a mean PAP ≥25 mm Hg in association with PAOP >15 mm Hg and PVR ≤3 Wood units.[3] This differen‐ tiation in preand post-capillary PH is important as it narrows the differential diagnosis and also has treatment implications.