Clinical relevance of endothelial dysfunction in cardiovascular disorders.

The potential role of endothelial dysfunction, defined by an imbalance in the production of endothelium-derived vasodilator and constrictor factors is discussed. Evidence is presented that increased endothelin-1 production plays an important role in the clinical and morphological manifestations of pulmonary hypertension, particularly in primary disease. As well, the potential contribution of a relative decrease in nitric oxide production to inappropriately elevated pulmonary vascular resistance in patients with secondary causes of pulmonary hypertension, particularly those with congestive heart failure is discussed.