CARDIAC HEMODYNAMIC-EFFECTS OF IODIXANOL, IOPAMIDOL, AND IOXAGLATE FOLLOWING LEFT CORONARY INJECTIONS IN ANESTHETIZED DOGS

Rationale and Objectives. Iodixanol, a dimeric, nonionic X-ray contrast medium, has been formulated at 320 mg iodine per milliliter and supplemented with Na+, Ca2+, and Cl- to produce an osmolality that approximates that of plasma. We compared the effects of left main coronary artery injections of iodixanol, ioxaglate, and iopamidol on cardiac mechanical function in dogs. Methods. Six mixed-breed dogs were anesthetized and prepared for recordings for electrocardiogram, aortic and left ventricular pressures, and the first derivative of left ventricular pressure, dP/dt. The test solutions and saline were injected into the left coronary artery in a randomized order. The series of four injections were repeated three times in each animal for a total of 12 injections per dog. Results. Iodixanol caused significantly lower (p < .05) reduction in peak left ventricular pressure (-1.7 +/- 0.9% vs -0.7 +/- 2.0%), in diastolic aortic pressure (-1.3 +/- 1.1% vs -9 +/- 1.3%), and in left ventricular dP/dt (0.3 +/- 1.3% vs -13.2 +/- 2.4%) than did ioxaglate. Iodixanol also produced smaller cardiovascular effects than did iopamidol, but the differences were not statistically significant. Injections of both iopamidol and ioxaglate caused significant decreases from baseline parameter values; however, the changes with iodixanol were not significant. Conclusion. The isotonic formulation of iodixanol caused smaller cardiovascular hemodynamic effects than did iopamidol and ioxaglate and may offer increased safety in patients with severe cardiac disease.