The choice of contrast agents in the cardiac catheterization laboratory.

The availability of newer and more expensive low osmolar contrast agents for cardiac angiography has forced a comparison with the standard ionic contrast agents. The milder hemodynamic effects of low osmolar agents make them the contrast of choice for the sickest patients; however, the existence of a reduction in the rate of anaphylactoid reactions or death during catheterization seems more doubtful. Guidelines for the selective use of the agents in the cardiac catheterization laboratory are offered, based on one hospital's experience of more than 20,000 procedures.