PULMONARY-HYPERTENSION - RESPONSE OF VASOACTIVE PEPTIDES TO A NONIONIC CONTRAST-MEDIUM IN PATIENTS UNDERGOING PULMONARY ANGIOGRAPHY

RATIONALE AND OBJECTIVES. The degree to which pulmonary angiography ma y contribute to serious complications in patients with pulmonary hyper tension has not been clarified and remains a matter of debate. Accordi ngly, this study was designed (1) to detect the potential release of v asoactive peptides and (2) to investigate the hemodynamic response aft er administration of a nonionic contrast medium in patients with pulmo nary hypertension undergoing pulmonary angiography. Allergy-mediating substances also were measured to monitor for possible anaphylactoid re actions. METHODS. Pulmonary digital subtraction angiography was perfor med in 20 patients with pulmonary hypertension (mean pulmonary arteria l pressure more than 20 mm Hg). Iopromide was administered as a total of 100 mL via a 7F catheter inserted from the right femoral vein. The injected volume and duration of injection (15 to 20 mL/sec) were kept constant. Hemodynamic parameters were continuously monitored, includin g electrocardiogram, heart rate, phasic and mean pulmonary arterial an d peripheral arterial pressures. Blood samples were obtained before an d after administration of contrast media to assay for the concentratio n of the following vasoactive peptides using radioimmunoassay techniqu es: renin, angiotensin-I-converting enzyme, angiotensin II, aldosteron e, atrial natriuretic peptide, antidiuretic hormone, cyclic-guanosine monophosphate, and myoglobin, as well as allergy-mediating substances such as tryptase, eosinophil protein X, and eosinophil cationic protei n. RESULTS. Administration of iopromide caused significant increases i n atrial natriuretic peptide (from 61.3 +/- 11.8 to 94.0 +/- 16.7) and antidiuretic hormone (from 6.6 +/- 1.9 to 12.3 +/- 3.1), whereas reni n significantly decreased (from 3.0 +/- 0.6 to 1.3 +/- 0.5). After adm inistration of contrast media, there were no significant changes in th e other measured vasoactive peptides, allergy-mediating substances, an d monitored cardiovascular parameters. CONCLUSION. Administration of i opromide for pulmonary angiography in patients with pulmonary hyperten sion resulted in no appreciable hemodynamic alterations associated wit h the observed changes in atrial natriuretic peptide, antidiuretic hor mone, and renin. No allergy-mediated reactions were observed in these patients.