REDUCED RISK OF VENTRICULAR-FIBRILLATION BY BALANCING SODIUM, CALCIUM, POTASSIUM AND MAGNESIUM ADDED TO NONIONIC CONTRAST-MEDIA - AN INVESTIGATION IN THE ISOLATED RABBIT HEART

The effect of addition of calcium, potassium and magnesium to iohexol (350 mg I/ml) enriched with 30 mM sodium was investigated with regard to ventricular fibrillation (VF) in isolated rabbit hearts. Enriching iohexol containing 30 mM sodium with increasing amounts of calcium (0- 1.2 mM) caused an increase in the frequency of VF. Increasing amounts of potassium (0-3.8 mM) to iohexol with 30 mM Na + 0.15 mM Ca + 0.1 mM Mg reduced the risk of VF. However, this protective effect of potassi um on VF was reduced if magnesium was removed from the test solution. Furthermore, increasing amounts of magnesium (0-1.2 mM) to iohexol wit h 30 mM Na + 0.15 mM Ca + 0.4 mM K led to an increased frequency of VF . Iohexol with 30 mM Na + 0.3 mM Ca + 0.9 mM K + 0.3 mM Mg caused no V F. It is of interest to add multiple cations to sodium-containing noni onic media to improve cardiac contractility following coronary perfusi on. The present study indicates that it is possible to enrich iohexol 350 mg I/ml + 30 mM Na with calcium, potassium and magnesium in small amounts, and balanced with respect to each ion, without changing the r isk of VE