Effects of contrast media on pulmonary hemodynamics: comparison of ionic and non-ionic agents.

Abstract

Injection of ionic contrast media into the main pulmonary artery induces an acute increase in pressure which was proposed as the underlying mechanism behind the morbidity and mortality associated with arteriography of the lungs in patients with pulmonary hypertension. Hemodynamic effects of pulmonary arterial injections of ionic (sodium methylglucamine diatrizoate) and non-ionic contrast media (iohexol) were compared in 9 anesthetized dogs which were maintained with an open thorax in a resting control state. Both increased pulmonary arterial pressure and cardiac output. Both resulted in decreased systemic vascular resistance, though the effect was significantly less with the non-ionic agent. Aortic pressure did not change with the non-ionic agent but fell drastically with the ionic agent. The predominant response of the pulmonary circulation to contrast media was a fall rather than a rise in pulmonary vascular resistance.