Comparison of the electrocardiographic and hemodynamic responses to ionic and nonionic radiocontrast media during...

The ECG and hemodynamic responses to a standard ionic radiographic contrast agent (diatrizoate) were measured and compared to those induced by iopamidol, a newly developed nonionic agent, during left ventriculography. Studies were performed using randomized double-blind techniques in 46 patients with suspected coronary artery disease who were scheduled for cardiac catheterization. A nuclear probe was used to measure left ventricular ejection fraction and relative ventricular volume before and immediately after left ventriculography. Bolus injections of diatrizoate and iopamidol induced similar significant decreases in left ventricular end-diastolic and end-systolic volume and similar significant increases in both left ventricular end-diastolic pressure (p less than 0.05) and systolic ejection fraction (p less than 0.01 vs baseline). Both agents induced modest increases in heart rate, but only the increase induced by diatrizoate was significant (p less than 0.01). The maximal rate of left ventricular pressure rise was not significantly altered by either agent. Iopamidol induced a slight increase in QRS duration (p less than 0.05); neither agent effected a significant change in QT duration. We conclude that the hemodynamic effects during left ventriculography using diatrizoate and iopamidol are similar. These findings do not justify the large-scale substitution of more expensive nonionic radiographic contrast agents for standard ionic agents such as diatrizoate in left ventriculography.