Slow-infusion of calcium channel blockers in the emergency management of supraventricular tachycardia.

OBJECTIVE

To compare the efficacy of verapamil and diltiazem as slow infusions in terminating spontaneous supraventricular tachycardia (SVT) in the emergency department (ED).

METHOD: Patients of at least 10 years of age who presented to our ED with regular narrow complex tachycardia not converted with a vagal manoeuvre with an ECG diagnosis of SVT were included. Those who were haemodynamically unstable were excluded. Patients were randomized to undergo either verapamil infusion at a rate of 1 mg/min to a maximum of 20 mg or diltiazem infusion at a rate of 2.5 mg/min to a maximum of 50 mg.

RESULTS

Eighty-one patients were randomized to receive verapamil infusion and 80 were randomized to receive the diltiazem infusion. There is no difference in success rate between verapamil (98.8%) and diltiazem (96.3%) infusion. The dose of medication required to convert 25,50 and 75% of SVTs were 4.0,5.0 and 8.0 mg for the verapamil infusion and 10.0,12.5 and 17.5 mg for the diltiazem infusion. There was one complication in each group.

CONCLUSION

Calcium channel blockers infusions were safe and efficacious in terminating spontaneous SVT. There was no difference between the success rates of verapamil and diltiazem infusions.