Intravenous diltiazem for the treatment of supraventricular tachycardia.

To determine the effects of diltiazem hydrochloride on patients with paroxysmal supraventricular tachycardia, we administered intravenous diltiazem, 0.25 mg/kg to patients who presented to the Stanford Medical Center Emergency Department with this rhythm. Blood pressure was recorded prior to administration, and monitored for 20 min thereafter. Six of the ten patients converted to sinus rhythm a mean of 7.75 min (+/- 4.4) after drug administration. The remaining four experienced slowing of heart rates from a mean of 177 to 166 beats/min. Systolic blood pressure fell a mean of 12.4 mmHg during treatment, but returned to pretreatment level or higher within 20 min following diltiazem administration. This mean degree of blood pressure reduction compares favorably with effects produced by intravenous verapamil under comparable circumstances. Intravenous diltiazem appears to be a safe and effective drug for the conversion of paroxysmal supraventricular tachycardia.