The distribution of plasma norepinephrine concentration and the relation of plasma norepinephrine concentration to pulmonary arterial pressure in heart disease

Plasma norepinephrine (NE) concentration was measured in blood samples from the pulmonary artery (PA), the superior vena cava (SVC), the inferior vena cava (IVC) and the femoral artery (FA) in 34 patients undergoing diagnostic cardiac catheterization. In patients with pulmonary hypertension, the mean plasma NE concentrations in PA, SVC and FA were significantly higher than that of IVC, but no such difference was found in patients without such hypertension. Except in IVC, the plasma NE concentration in patients with pulmonary hypertension was significantly higher than in others. Furthermore, the plasma NE concentration was positively correlated with the mean pulmonary arterial pressure and inversely related to pulmonary arterial oxygen saturation in patients without a shunt. These results suggest the possibility that vasoconstriction by the sympathetic nervous system may contribute to the development of pulmonary hypertension in patients without the shunt.