Effect of angiographic contrast agents on the mechanical performance of the isolated rat papillary muscle preparations.

The effects of the radiographic contrast agents Renografin, Isopaque, and Hypaque on the mechanical performance of isometrically contracting rat papillary muscle was compared to a new contrast agent, Amipaque. It was found that exposure to Amipaque resulted in significantly less depression of contractile activity than any of the other agents. Changes in mechanical performance associated with exposure to Renografin, Isopaque, or Hypaque could not be attributed to either hypocalcemia or hypoxia. The decrease in developed tension and increase in resting tension was similar to that produced by Krebs-Henseleit containing hypertonic (1420 mmol) glucose or sucrose. Thus, the data support the concept that hyperosmolarity of the radiographic contrast agents may be primarily responsible for the adverse effects on mechanical performance of the myocardium associated with angiography.