Iodine contrast substances (CS) are used since the twenties of the 20th century. From the chemical aspect benzoic acid derivatives are involved which are classified according to their osmolality (high-low- and isoosmolar) tendency of ionization (ionic and non-ionic) and according to the molecular structure monomers and dimers).Side-effects are due to their osmotic, ionic and chemical action on tissues. They include a number of systemic and organ symptoms ( cardiovascular, immunological, haemocoagulation, neurological and renal), from the clinical aspect divided into mild, medium severe and severe. The relatively high incidence of undesirable reactions when ionic high-molecular CS are used led to the development of non-ionic preparations with a lower osmolality, the more extensive use of which is limited by economic factors. Moreover so far convincing clinical data are lacking that the higher incidence of undesirable reactions after the use of CS has a clinical impact. Objective: To summarize experience with administzration of CS in the catheterization laboratory of the Cardiocentre of the General Faculty Hospital during diagnostic and intervention procedures within 5 years with regard to the occurrence of undesirable effects when comparing ionic and non-ionic CS. Method: retrospective analysis of a group of patients examined in the catheterization laboratory to whom a CS was administered during the period between Jan.1 1995 and Dec. 31 1999. Results: In 1995-1999 (5 years) in the catheterization laboratory a total of 10 149 procedures where implemented where ionic(ioxitalam -Telebrix 350) and non-ionic (iopromide Ultravist 370, ioversol - Optiray 370 and iomeprol-Iomeron 350) contrast substances were administered. Ionic CS were administered in 4 668 (46 %) and non-ionic CS in 5 481 (54 %) instances. Undesirable effects were recorded in a total of 107 (1.1 %) patients, incl. ventricular fibrillation in 76 (0.75 %), cardiac arrest in 12 (0.12 %) and in 19 (0.19 %) there were other undesirable effects (weakness, nausea, hypotension, flush, urtica etc.). Ionic and non-ionic CS participated equally in complications: ionic CS in 53 (49.5 %) cases and non-ionic CS in 54 (50.5 %), whereby no difference was observed in the type of complications.No death in conjucntion with administration of CS was observed. Conclusion:The use of contemporary contrast substances in the catheterization laboratory for diagnostic and intervention procedures on the heart is relatively safe with a minimal risk of development of serious complications. No difference was observed between the use of ionic and non-ionic CS.

        Key words: Ionic and non-ionic contrast substances - Complications after administration of contrast substances - Cetheterization laboratory