Contrast media-induced side effects on excitation and conduction of electrical activity in the heart on intracardiac application. Investigations in anaesthetized dogs.

In several series of experiments with intracardiac application in anaesthetized dogs, the following contrast media were tested for their adverse effects on excitation and conduction of electrical activity in the heart. Diatrizoate, lysine-diatrizoate, lysine-sodium-diatrizoate, ioxaglate, iopamidol, iodamide, ioxitalamate, ioglicinate and metrizamide. Blood pressure and, using the His' bundle-ECG technique, the parameters P0-P1 (heart rate), A1-H1 period (conduction time in the AV-node), and H1-V1 period (conduction time in the TAWARA branches) were measured. A statistical correlation exists between osmolarity and blood pressure (higher osmolarity causes a greater decrease in blood pressure), as well as between osmolality and decrease in heart rate (higher osmolarity causes a greater decrease in heart rate). The delay in conduction time in the AV-node correlates only with viscosity and sodium content (increased viscosity with increased sodium content delays the time of conduction). A tendency towards delay in conduction in the TAWARA branches could not be correlated to any one of the physico-chemical parameters studied.