Systemic hemodynamic pattern in primary hyperparathyroidism and its changes after parathyroidectomy.

Twelve patients (7 men and 5 women) with an average age of 53 years (range 37-69) were hospitalized for renal stones and found to have primary hyperparathyroidism. Five were hypertensive and 7 normotensive. The systemic hemodynamics, plasma renin activity and glomerular filtration rate were evaluated before and at least 6 months after removal of a parathyroid adenoma. After surgery the mean intra-arterial blood pressure fell in almost all patients, due to some reduction in the peripheral vascular resistance index with no change in the cardiac index. However, the hemodynamic variations were not uniform in all patients. No change was seen in plasma renin activity and glomerular filtration rate. A positive correlation between the percent change in mean arterial pressure and percent decrease in total serum calcium was found. The results obtained indicate that it is likely that hypercalcemia plays some role both in patients with high and those with normal blood pressure. The systemic hemodynamic changes after parathyroidectomy indicate that the fall in peripheral vascular resistance could have a certain influence.