[Intracellular microelectrode study of the electrophysiological effects of contrast media]

Intracellular microelectrodes were used to study the electrophysiological effects on action and resting potentials, refractory periods and conduction velocities of four contrast media administered either as 1/100 and 1/1000 solutions or as 20 mg bolus injections. The products studied were Telebrix, which has high osmolality (2100 mOsm/kg) and three other contrast media with lower osmolatity (700 mOsm/kg), including Hexabrix, which contains sodium, and Iopamidol and Iohexol which are sodium-free. The parameters measured were not modified by Hexabrix and Telebrix, whereas Omnipaque and Iopamiron induced varied and significant changes in these parameters, notably in concentrations of 1/100 and as bolus injections. It is suggested that the latter contrast media should be used in non-cardiovascular explorations and in patients without confirmed heart disease.