Sodium-calcium balance in nonionic contrast media. Effects on the risk of ventricular fibrillation in the isolated rabbit heart.
OBJECTIVE
During coronary arteriography the blood is replaced for a short period of time with a contrast medium (CM) solution. The CM may cause a risk of arrhythmias and ventricular fibrillation (VF). Previous investigations have shown that the addition of small amounts of sodium (10-30 mmol/L) to nonionic CM may decrease the risk of VF from these media. Calcium addition to nonionic CM may reduce a negative inotropic effect. In the current investigation, the changed risk of VF from nonionic CM with 19 to 30 mmol/L NaCl was studied when the media also contained calcium or calcium and magnesium.


METHODS
An isolated rabbit heart model was used. The risk of arrhythmias and VF from the nonionic monomer iohexol and the nonionic dimer iodixanol containing 19 to 30 mmol/L NaCl with 0 to 2.5 mmol/L calcium as CaCl2 was studied. In the series with iodixanol, 0 to 0.95 mmol/L MgCl2 also was added to the solutions with sodium and calcium, but the role of magnesium was not especially evaluated in the investigation.


RESULTS
Nonionic CM with small amounts of NaCl (19-30 mmol/L), without calcium or with calcium at the level of 0.05 to 0.3 mmol/L, caused the lowest risk of VF. When relatively higher additions of calcium reached the physiologic concentration of 2.5 mmol/L, the CM caused a greater risk of arrhythmias and VF.


CONCLUSIONS
When calcium is added to a nonionic CM, the concentration of calcium must be balanced against the NaCl concentration to minimize the risk of VF. Excessive calcium concentration will increase the risk of VF.
Bååth
L
L
Department of Experimental Research, Malmö General Hospital, University of Lund, Sweden.
Besjakov
J
J
Oksendal
A
A
D000818:Animals; D002118:Calcium / Q000009:adverse effects / Q000032:analysis*; D003287:Contrast Media / Q000009:adverse effects / Q000737:chemistry; D017023:Coronary Angiography; D066298:In Vitro Techniques; D007472:Iohexol / Q000009:adverse effects* / Q000737:chemistry; D011817:Rabbits; D012307:Risk Factors; D012964:Sodium / Q000032:analysis*; D014283:Triiodobenzoic Acids / Q000009:adverse effects* / Q000737:chemistry; D014693:Ventricular Fibrillation / Q000139:chemically induced*
D003287:Contrast Media; D014283:Triiodobenzoic Acids; D007472:Iohexol; D012964:Sodium; C044834:iodixanol; D002118:Calcium