[en] Minimal cardiac transit times are an expression of the maximal velocity of cardiac blood flow. They are related to the mean velocity, and therefore to the ejection fraction. The transit times are easily measured with the help of short-lived radionuclides and with a fast gamma camera. Sensitivity, reproducibility and clinical of minimal cardiac transit times were proven in more than 4.000 measurements in patients with ischemic heart diesease, with myocardial insufficiency with and without digitalis therapy, in patients with valvular disease after surgical insertions of multiple protheses, and in patients with hypothyroidism. Because of the high sensitivity of the method, minor alterations of cardiac function may be detected which are otherwise clinically not easily obtainable. (orig.)