Hypaque-76 (H76) and Renografin-76 (R76) are nearly identical ionic contrast media, except that R76 binds more calcium than H76 because of the presence of sodium citrate and EDTA in R76. To determine whether the calcium-binding additives in ionic contrast media contribute to the hemodynamic effects of contrast media during coronary angiography, left coronary angiography was performed in anesthetized dogs. In nine closedchest dogs, 10 cc of H76 and R76 were injected in each dog in a blinded, randomized fashion. The effect of H76 and R76 on left ventricular systolic pressure (LVSP) and left ventricular diastolic pressure (LVDP), on mean aortic pressure (MAP), and on left ventricular (LV) dpldt was recorded. Compared with H76, R76 produced a greater decrease in the LVSP (77 * 25 mmHg vs 48 f 17 mmHg P< .05), MAP (72 f 24 mmHg vs 38 f 18 mmHg P< .Ol), and LV dpldt (747 * 87 mmHglsec vs 460 f 81 mmHglsec P< .01).
In nine additional open-chest dogs, left coronary angiography was performed 1 hour after occlusion of the proximal LAD coronary artery. Seven cc R76 produced a 35 f 15 mmHg decrease in LVSP, compared with 20 & 9 mmHg with H76 (P< .01). The LV dpldt decreased 720 f 387 mmHglsec with R76, compared with 462 f 222 mmHglsec with H76 (P< 0.05). Thus, R76 produces significantly greater hemodynamic abnormalities than H76. Contrast media lacking calcium-binding agents may be preferable for coronary angiography.