Pulmonary hypertension in parenchymal lung disease.

The pathophysiology of pulmonary hypertension (PH) in parenchymal lung diseases is partially related to hypoxic pulmonary vasoconstriction. PH treatment is controversial for these patients. This article focuses on group III PH, namely PH attributable to lung diseases and/or hypoxia. Group III includes chronic obstructive pulmonary disease and interstitial lung diseases, the most common parenchymal lung diseases associated with PH. It also includes sleep-disordered breathing and hypoventilation from any cause. Other parenchymal lung diseases associated with PH, namely sarcoidosis and systemic vasculitides (group V), are discussed. The data describing PH in specific parenchymal diseases are reviewed.