Hk. Pedersen et al., CONTRAST-MEDIUM-INDUCED VENTRICULAR-FIBRILLATION - ARRHYTHMOGENIC MECHANISMS AND THE ROLE OF ANTIARRHYTHMIC DRUGS IN DOGS, Academic radiology, 2(12), 1995, pp. 1082-1088
Rationale and Objectives. Small electrolyte additions re, a nonionic c
ontrast medium reduce the risk of ventricular fibrillation (VF) during
wedged catheter injection of a contrast medium. The current study was
designed to further investigate contrast-medium-induced VF by studyin
g the effect of pretreatment with different antiarrhythmic drugs. Meth
ods. During a simulated wedged catheter situation, iohexol was injecte
d into the anterior descending branch of the left coronary artery in f
ive open-chest, anesthetized dogs pretreated with lidocaine, propranol
ol. amiodarone, almokalant, or verapamil. Results. Wedging the cathete
r far 60 sec did not induce VF. However. all 15 wedged catheter inject
ions with iohexol induced VF within 28 sec (19 +/- 1 [mean +/- standar
d error of the mean]) despite pretreatment with antiarrhythmic drugs.
Prior to VF. conduction was slowed and monophasic action potential dur
ation lengthened in the contrast-medium-perfused myocardium. although
no significant changes occurred in the control area. Conclusion. The c
ombination of catheter wedging and long-lasting contrast medium inject
ion has a high risk of causing VF. Although adding a small amount of e
lectrolytes to nonionic contrast media can reduce the risk of VF, anti
arrhythmic drug therapy may not have a protective effect.