Pulmonary hypertension: Newer concepts in diagnosis and management

Pulmonary hypertension comprises a family of disorders occurring as a primary disease or as a complication of a large number of respiratory and cardiac diseases. Pulmonary hypertension is present when pulmonary artery pressure or mean pressure exceeds 30 mmHg or 20 mmHg, respectively. Underlying the hemodynamic changes that result in pulmonary hypertension, whether from hypoxia, acidosis, increased pulmonary blood flow, increased shear stress, or idiopathic causes, is a dysfunctional vascular endothelium. In this review, the role of the history and physical examination in the initial assessment is emphasized. Newer diagnostic modalities, such as subselective pulmonary angiography and ultrafast computed tomography scanning, are reviewed. Low-flow oxygen, anticoagulation, and calcium-channel blockade are presented as accepted therapeutic modalities. Inhaled nitric oxide and prostacyclin infusion are presented as newer therapies that may be useful given the limited availability of donor organs for heart-lung transplantation. Future therapeutic strategies are likely to develop from advances in vascular biology.