Effects of intravenous administration of a new nonionic dimeric contrast medium on the coronary circulation. Comparison with monomeric ionic and nonionic media.

Contrast media injected into the circulation produce a variety of cardiovascular effects. Agents with low osmolality and low concentrations of cations cause considerably less hemodynamic effects. This study compared the effects of a nonionic dimer, iotrol, which has an osmolality (340 mosm/kg) close to that of serum (290 mosm/kg), with a standard ionic monomer, meglumine diatrizoate, and a nonionic monomer, iosimide. The effects of intravenous bolus injection of these three contrast agents on coronary and systemic hemodynamics were studied in eight anesthetized dogs. The influence of the contrast media on subendocardial and subepicardial perfusion was assessed by injecting radioactive microspheres into the left atrium 30 seconds after injection of the media. Alterations in coronary hemodynamics occurred with both iosimide and meglumine diatrizoate. Iotrol produced minimal changes in coronary hemodynamics. Thus, iotrol is the least perturbing contrast indicator and seems the best for use in quantitative digital subtraction and dynamic computed tomography studies designed to measure myocardial perfusion.