Administration of intravenous calcium before verapamil to prevent hypotension in elderly patients with paroxysmal supraventricular tachycardia.

The aim of this study is to evaluate the effects on blood pressure and heart rate of i.v. calcium before the administration of verapamil during the treatment of paroxysmal supraventricular tachycardia (PSVT) in elderly patients. Administration of i.v. verapamil with or without preceding i.v. calcium administration was performed in elderly patients with PSVT. Verapamil (1.0 mg/min) was administered i.v. in 10 patients (Group A) and calcium (3.75 mg/kg for 5 min) followed by verapamil (1.0 mg/min), which was administered i.v. in seven patients (Group B). Blood pressure and heart rate were measured during the study every 5 minutes. Verapamil was effective in suppressing PSVT in both groups. In Group A, i.v. verapamil caused sustained decreases in blood pressure and heart rate over 25 min. In Group B, systolic blood pressure transiently fell immediately after administration of i.v. verapamil, but reversed to the baseline level in 5 min. The absolute and percentage decreases in blood pressure were significantly smaller in Group B than in Group A, whereas changes in heart rate were identical in both groups. Thus, i.v. calcium was effective in preventing hypotension during the treatment of PSVT with verapamil. This regimen was beneficial for elderly patients, since a sufficient dose of verapamil for suppressing PSVT could be administered without causing hypotension.