CARDIOVASCULAR PARAMETERS IN TRANSITORY H YPOTHYROIDISM

Cardiovascular manifestations are a frequent finding in hypothyroidism . Thus, blood-pressure measurements, longtime electrographic monitorin g, and spiroergometry were examined in 20 patients with transitory hyp othyroidism. In the patients with thyroid carcinoma, total thyroidecto my was performed. Measurements were made in hypothyroidism and after T SH-suppression with L-thyroxine. Thirty-five patients in whom intracar diac catheter examination ruled out cardiopulmonary disease served as controls. Cardiopulmonary exercise was done by bicycle exercise testin g. In transitory hypothyroidism an increase of diastolic blood pressur e was found at rest (p = 0.02) and during exercise (p = 0.002), which was reversible after T4-therapy. Compared to the controls diastolic bl ood pressure in hypothyroidism was increased at rest (p = 0.014) and d uring exercise (p = 0.005). EGG-monitoring showed a day-night differen ce in heart rate in hypothyroid patients and after therapy. The mean h eart rate (74 vs. 88 beats per minute; p = 0.0006), the minimal (p = 0 .0062) and the maximal heart rate (p = 0.0016) during the day were dec reased in hypothyroidism compared to euthyroidism. There were no atrio ventricular blocks in transitory hypothyroidism and no increase of ven tricular or supraventricular premature beats after high-dose T4-treatm ent. Spiroergometry showed no change in ventilation and an increased g rowth in heart rate (p = 0.021) associated with good working capacity in hypothyroid patients. Heart rate at rest (p = 0.004) and at the ana erobic threshold (p = 0.03) were decreased in transitory hypothyroidis m.