[Isotopic study of cardiac hemodynamics after multiple valve prothesis (author's transl)]

The radiocardiography of the minimal transit times (MTTs) produces cardiologically useful hemodynamic data also in such instances where invasive techniques with the cardiac catheter are technically difficult, as is the case in patients with multiple valve prothesis. The present study reports on MTT measurements in 9 patients with tricuspidal prothesis, 8 of which had additional mitralvalve prothesis and 2 additional aortic valve prothesis. The measurements were made with Tc-99m Pertechnetate, and an Anger camera with electronic data processing was used as detector system. The results indicate that following implantation of valve prothesis the hemodynamic state remained essentially disturbed. The pathologically altered transit times are an expression of disturbed volume ratios. The transit times in the atria remained prolonged by an average factor of 4-5. The ejection of the left ventricle stayed diminished more pronounced than on the right. The values of one patient who was examined before and after implantation of the prothesis in mitral and tricuspidal position, also showed a worsening of the data especially in the atria. Because the cardiac function study with radioisotopes is non invasive, simple, and fast, and leads to only a minor radiation burden, the method may be repeated and without hazard used for control follow-ups.