[Alteration of coronary blood flow after injection of a contrast medium (author's transl)].

The injection of with different, energetic separable radioactive isotope labelled particles in the same coronary artery before and short after the injection of a contrast medium reveals in many cases variable scintigraphic pictures. The temporary vasodilatation caused by the contrast medium produces in presence of a coronary stenosis a disturbance of the regional blood flow. Thereby we find in the poststenotic myocardial area a transient ischemia, bringing about a decrease of the activity at the scintigram. As this transient ischemia is only demonstrable with a hemodynamic effective stenosis, in such cases a good effect of coronary surgery can be expected. On the other hand, in the presence of effective stenoses in all three coronary branches, in the double-scintigram alterations of the perfusion can be missed, showing the same scintigraphic picture as with normal coronary arteries.