The risk of contrast media-induced ventricular fibrillation is low in canine coronary arteriography with ioxilan

Previous studies have proposed that sodium supplement to nonionic contrast media (CM) can decrease the risk of ventricular fibrillation (VF). This stu dy was designed to compare the occurence of VF induced by ioxilan (containi ng 9 mmol/LNa+) with other nonionic CMs. After wedging a catheter in the ri ght coronary artery, test solutions including ioxilan, ioversol, iomeprol, and iopromide were infused for 30 sec at the rate of 0.4 ml/sec or until VF occurred. Then, incidence of VF, contact time (i.e. the time required to p roduce VF), and QTc were measured. Also, the CMs other than ioxilan were in vestigated at sodium levels adjusted to 9 and 20 mmol/L Na+. The incidence of VF with ioxilan (0%) was the lowest of all. In the other CMs, the incide nce decreased in accordance with increase of sodium. Iomeprol and iopromide showed significant reduction of VF incidence at the sodium level of 20 mmo l/L. The higher sodium supplements also prolonged the contact times. The in crease of QTc was the greatest in ioxilan. Ioxilan has the least arrythmoge nic property among the current low-osmolality nonionic CMs. This property m ight be attributable to an optimal sodium concentration of 9 mmol/L in the CM.