Effect of sodium addition to non-ionic contrast media on cardiac contractile force. Perfusion of the isolated rabbit heart with iohexol and iopentol containing 0 to 154 mmol Na+/l added as NaCl.

Cardiac contractile force after adding NaCl to the non-ionic contrast media iohexol and iopentol was investigated in the isolated rabbit heart. Iodine concentrations of 150, 300 and 350 mg I/ml were used with sodium concentrations ranging from 0 to 154 mmol/l. From physiologic experiences of nutrient solutions it should follow that a sodium-free solution of a non-ionic contrast medium, which also has the lowest hypertonicity, should cause the smallest decrease in contractile force. However, a small amount of sodium added to the contrast medium solutions, in the range of 19.25 to 38.5 mmol/l, caused the least decrease in contractile force. The decrease in contractile force was significantly more pronounced when no sodium was added or when larger amounts of sodium were added. A small amount of sodium also decreases the risk of ventricular fibrillation. Thus there is a possibility that addition of sodium could reduce the adverse effects of cardioangiography.