CARDIAC EFFECTS OF IODIXANOL COMPARED TO THOSE OF OTHER NONIONIC AND IONIC CONTRAST-MEDIA IN THE ISOLATED RAT-HEART

This study was designed to compare the cardiac electrophysiological an d mechanical effects of iodixanol to those of iotrolan, iopromide, iox aglate and diatrizoate. Two consecutive injections of contrast media ( CM) (0.3 g I/kg and 0.9 g I/kg b.w.) were given to spontaneously beati ng, LANGENDORFF-perfused rat hearts. CM were given as a single, short- lasting bolus injection (i.e., over 2 and 5 s). Changes in aortic pres sure, left ventricular pressures and ECG were continuously recorded du ring constant volume perfusion. The nonionic CM had less pronounced ef fects on aortic pressure than had the ionic media. The peak rate of is ovolumetric contraction (LV dP/dt(max)) was slightly decreased by iodi xanol and iotrolan, slightly more decreased by iopromide and markedly decreased by ioxaglate and diatrizoate. Similarly, the peak rate of pr essure decline (LV dP/dt(min)) was only slightly decreased by iodixano l and iotrolan. Also, the 2 nonionic dimers had the smallest effects o n left ventricular enddiastolic pressure (LVEDP) and heart rate. Ioxag late lengthened the PQ-interval, but less so than diatrizoate. The QT- interval was only slightly lengthened by iodixanol and iotrolan, as co mpared to the lenghtening caused by iopromide, ioxaglate and diatrizoa te. Single ventricular extrasystoles were seen in all groups. Extrasys toles up to 3 coupled beats were registered after ioxaglate and diatri zoate. No episodes of ventricular fibrillation occurred with any CM. I n conclusion, the nonionic dimers, and in particular iodixanol, induce only minor changes in cardiac function, whereas the ionic dimer ioxag late and the ionic monomer diatrizoate induce pronounced effects.