[Minimal cardiac transit time in thyroid disorders and in the effort syndrome]

Minimal transit times (MTTs) were determined with the Fucks-Knipping gamma camera from differences between arrival times in consecutive cardiac compartments of blood radioactively labelled with 113m-In-DTPA Measurements were made on 50 patients with effort syndrome, 59 patients with hyperthyroidism before and after thyroid suppression therapy partly suffering from associated heart disease, and 25 patients with hypothyroidism before and after therapy with thyroid hormone. In patients with effort syndrome and hyperthyroidism, MTTs were often, but not always shortened below the control values; consequently, in case of associated heart disease, MTT-prolongation may be masked in such instances where hyperthyroidism causes MTT shortening. Hypothyroidism caused MTTs to be prolonged. The prolonged MTTs reverted to normal values upon adequate therapy with thyroid hormone.