Hemodynamic Studies in Hyperthyroid Patients

ABSTRACT

Hemodynamics in 60 normal, 15 simple goiter and 40 hyperthyroid subjects were determined from non-invasive Wezler's method. Hemodynamic changes in hyperthyroid patients were compared with those of normal subjects. The relationships of the cardiac output, aging,131I uptake rate and PEP/LVET to the hemodynamic changes in Hyperthyroid patients were also discussed. 1) The hemodynamics of normal subjects were same as those of simple goiter. 2) The heart rate and cardiac output were increased very significantly in hyperthyroid patients but they appeared to decrease with age. The stroke volume was increased slightly in the hyperthyroid patients, but remained unlateerd even with aging. Peripheral arterial resistance in hyperthyroid patients was decreased but appeared to increase with age. 3) As the131I uptake rate increased, the heart rate, cardiac output also increased, but PEP/LVET as an index of myocardial contractility and the peripheral arterial resistance decreased. 4) PEP/LVET as an index of myocardial contractility in hyperthyroid patients was markedly reduced. 5) The relationship of stroke volume and the rate of the heart to cardiac output in normal subjects were reasonably linear, and peripheral arterial resistance has negative relation to cardiac output. However the heart rate, though increased in most patients with thyrotoxicosis, bears no close relations to the level of cardiac output increment. The relationshop of stroke volume to cardiac output in hyperthyroid patients is reasonably linear and peripheral arterial resistance has negative correlation with the cardiac output.