Estimation of systolic time intervals and timing of arterial sounds in hyperthyroidism during antithyroid medication

During antithyroid drug therapy hyperthyroid patients with border-line elevated serum T3 had shortening of pre-ejection period (PEP) and QKd interval (period between the onset of QRS complex and the onset of the Korotkoff arterial sound). There was a significant relationship between PEP and QKd interval with serum T3 concentration in a group of patients under medical therapy; PEP and QKd were normalized later than serum thyroid hormone concentration in such patients. Propranolol induced a prolongation of PEP and QKd interval in hyperthyroid patients. PEP and QKd are sensitive measures of metabolic status in thyrotoxic patients during antithyroid treatment.