The response of heart rate to isoproterenol in hemodialyzed patients before and after parathyroidectomy.

The response of the heart rate to intravenous isoproterenol was studied in seven chronic hemodialysis patients with severe hyperparathyroidism, before and after subtotal parathyroidectomy (PTX). Before PTX, significantly higher doses of isoproterenol were needed to achieve a standardized increase in heart rate when compared with the doses needed following PTX. A similar difference was observed before and after removal of a parathyroid adenoma in an additional nonuremic patient with primary hyperparathyroidism. This decreased cardiac responsiveness to a beta-adrenergic stimulus seemed to be related to the hyperparathyroid state.