“…A review of the literature by Lemann & Donatelli (1964) has shown that in cases of acute hyperparathyroidism while the pulse rate may be as high as 120, tachycardia is not a constant feature. When hyperparathyroidism co-existed with thyrotoxicosis, tachycardia was always present and ranged from 120 to 160/min (Bryant, Wulsin & Altemeirer, 1964). While undue reliance cannot be placed on the presence of tachycardia in very ill dehydrated patients, we suggest that in such patients suffering also from hypercalcaemia, a pulse rate of over 120/min should suggest the possibility of coexisting thyrotoxicosis.…”