Effects of metrizamide, a new nonionic contrast medium, on cardiac function during coronary angiography in the dog.

Metrizamide is a new non-ionic radiopaque agent with low osmolarity and low intravenous toxicity. Hyperosmolarity is one of the factors involved in the decrease of myocardial contracility, alterations of aortic pressure, and disturbances in the cardiac rhythm which contrast media induce during coronary angiography. Metrizamide has been compared to other commonly used contrast media and was shown to produce fewer changes on the cardiac functions recorded.