[Changes in atrial natriuretic peptide in patients with lung embolism and obstructive respiratory tract disease].

Plasma levels of atrial natriuretic peptide (ANP) correlate closely with the pressure and mural tension of the right atrium and with pulmonary arterial pressure. We determined ANP levels in eight patients with scintigraphically confirmed pulmonary embolism, before and after reperfusion. Furthermore, ANP was measured in ten patients with acute obstruction of the airways, and during the course of clinical recovery. Peripheral venous blood was saved for determination of ANP plasma levels. The hormone concentrations were measured by radioimmunoassay. In ten patients with scintigraphically confirmed pulmonary embolism clearly higher ANP plasma levels were determined than after complete reperfusion (p less than 0.05). In patients with acutely exacerbated airways obstruction, hormone levels were measured which were significantly higher than those observed after clinical improvement (p less than 0.01). Since it is known, that ANP reduces pulmonary arterial smooth muscle tone and resistance, the hormone appears to be of physiological significance in pulmonary embolism and acute airways obstruction by lowering right ventricular afterload.