Comparative Hemodynamic Effects of Equiosmolar Injections of Angiographic Contrast Materials

Abstract

Hemodynamic responses to angiocardiography have been attributed to marked hyper tonicity of radiocontrast agents. So that the importance of osmolarity in these responses could be determined, equiosmolar amounts of three radiopaque materials (Hypaque-M, Renografin-76 and Angio-Conray) and a hypertonic solution of mannitol were injected into ten dogs. Rapid left ventricular injections were made at 30-mIn intervals. Cardiac output, systemic arterial pressure and pulse rate were measured before and 15 sec, 2μmim and 5 min after injection. The characteristic hemodynamic effects of angiocardiography-transient systemic hypotension, increased cardiac output and diminished systemic resistance-occurred consistently with each material. Quantitative differences in responses between materials were inconsistent and infrequently significant. Mannitol differed from the contrast media only in evoking less hypotension at 15 sec and less cardiac output increase after 2μ min than Hypaque. The findings support the concept that osmolarity is the major determinant of the hemodynamic effects of angiocardiography.