HEMODYNAMIC-EFFECTS OF NONIONIC CONTRAST BOLUS INJECTION AND OXYGEN INHALATION DURING PULMONARY ANGIOGRAPHY IN PATIENTS WITH CHRONIC MAJOR-VESSEL THROMBOEMBOLIC PULMONARY-HYPERTENSION

Background Pulmonary angiography is the gold standard for the diagnosi s of chronic thromboembolic pulmonary hypertension; however, major com plications have been reported. This study evaluates the hemodynamic ef fects of direct pulmonary nonionic contrast bolus injection and oxygen inhalation in patients with chronic thromboembolic pulmonary hyperten sion. Methods and Results In 33 patients, hemodynamic parameters were measured after oxygen inhalation and during bolus injection of nonioni c contrast medium in a control group (group 1, n=11), in a group of pa tients with moderately severe pulmonary hypertension (group 2, n=9), a nd in a group with severe pulmonary hypertension (group 3, n=13). Oxyg en inhalation significantly improved oxygen supply. Pulmonary artery p ressure and heart rate were reduced, but pulmonary vascular resistance and total pulmonary resistance were not significantly affected. One h undred ninety-eight angiograms were performed selectively on both pulm onary arteries in the posterior-anterior, oblique, and lateral views. Before contrast bolus injection, RAP and PAP significantly increased b ecause of initial inspiration. Contrast bolus injection caused only a minor pressure increase (Delta PA systolic, 2.3+/-1.4, 2.5+/-1.8, and 5.0+/-5.2 mm Hg, groups 1, 2, and 3, respectively) without significanc e between the groups. After the angiography, pulmonary artery pressure was moderately increased, predominantly in group 3, but pulmonary vas cular resistance was not significantly changed. Systemic vascular resi stance was decreased. Cardiac index increased in groups 1 and 2 but wa s unchanged in group 3. Systemic pressure there fore decreased in grou p 3. Conclusions We concluded that bolus injection of nonionic contras t medium causes no major hemodynamic effects even in patients with sev ere chronic thromboembolic pulmonary hypertension. Oxygen contributes to safety during the procedure.