Influence of a radiographic contrast media (Iopentol) with different viscosities on capillary perfusion in patients with coronary artery disease.

Radiographic contrast media (RCM) are widely used to visualize blood vessels. Their effects on blood vessels should be minimal so that the object of the measurement - the vessel lumen - is not influenced by the RCM molecules. However, all RCMs exhibit a more or less strong effect on endothelial cells as well as on erythrocytes. These effects are discussed to induce a significant and relevant deceleration of the microcirculation. For some RCMs this could be demonstrated in animal or clinical studies. Therefore, this study investigated the role of the viscosity of a RCM on the mean erythrocyte velocity in nail fold capillaries in patients with coronary artery disease after a bolus injection of the RCM directly into the A. axillaris. Iopentol-350 is a high-viscous Xray contrast medium and induced a short-lasting imbalance of the microcirculation already in vascular regions not affected by atherosclerosis. This effect was - in the early phase after injection - significantly stronger than after application of the low viscous Iopentol-150. In patients with severe coronary artery disease and a myocardial perfusion at its limits, the injection of high-viscous X-ray contrast media could induce massive perturbations in the microcirculation and even ischemia. As a consequence a further impairment of both systolic and diastolic functions may occur.