Low-osmolality contrast media-induced ventricular fibrillation.

We evaluated the incidence of ventricular fibrillation with low-osmolality contrast media by right coronary arteriography in eleven adult mongrel dogs. Following insertion of the catheter into the right coronary artery, a test solution was infused for 25 seconds (total 11 mL) or until fibrillation occurred. The test solutions included 20% mannitol, ioxaglate, iopamidol, iotrolan, and sodium iopamidol, which contained 150 mEq/L sodium in solution. The incidences of ventricular fibrillation were 0% with iotrolan, 8.3% with sodium iopamidol, 10% with ioxaglate, and 100% with iopamidol and mannitol. These observations suggest that the absence of sodium ions is a critical factor in fibrillation, even in low-osmolality contrast media. The fact that iotrolan had the least arrhythmogenic property may be attributed to the 8 mEq/L of sodium ions in that agent.