Contrast media-induced ventricular fibrillation: an experimental study of the effects of dimeric contrast media during wedged catheter injection in dogs.

RATIONALE AND
OBJECTIVES: We investigated the cardiac effects of an ionic dimer, ioxaglate and two nonionic dimers, iotrolan, and iodixanol.
METHODS: During a simulated wedged catheter situation, 22 ml of each contrast medium was injected into the left anterior descending branch of the left coronary artery in seven open-chested, anesthetized dogs.
RESULTS: Of 13 injections with each contrast medium, ioxaglate induced ventricular fibrillation in 11 after 34 +/- 5 sec, iotrolan in 6 after 42 +/- 4 sec, and iodixanol in 3 after 61 +/- 1 sec. Ioxaglate markedly lengthened monophasic action potential duration in contrast medium-perfused myocardium. Iotrolan, and iodixanol induced biphasic changes, first lengthening and then shortening action potential duration. The electrophysiological changes occurred later when using iodixanol.
CONCLUSIONS: The risk of ventricular fibrillation during long-lasting contrast media exposure to the myocardium, as in a wedged catheter situation, appears to be much lower with iodixanol compared with ioxaglate and also lower than when using iotrolan.