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AND CDNDUCllON DtSTUR6ANCES
Acute Conversion of Paroxysmal Supraventricular Tachycardia with Intravenous Diltiazem Anne Hamilton Dougherty, MD, Warren M. Jackman, MD, Gerald V. Naccarelli, MD, Karen J. Friday, MD, and Virgil C. Dias, PharmD, for the IV Diltiazem Study Group Dfltiazem has electrophysiologic effects similar to those of verapamil. Its efftcacy and safety in 4 doses for treatment of induced supraventricutar tachycardia (SVT) were examined and compared with those of placebo in 87 patients (25 with atrtoventricular [AV] nodal reentry tachycardia, 60 with AV reentry associated with an accessory AV connection, and 2 with atrial tachycardia). Conversion to sinus rhythm occurred in 4 of 14 patients (29%) with 0.05 mg/kg of dlttiaxem, 16 of 19 (64%) with 0.15 mg/kg, 13 of 13 (100%) with 0.25 mg/kg, and 14 of 17 (62%) with 0.45 mg/kg compared with 6 of 24 (25%) treated with placebo. Converston rates in groups recetving doses of 0.15 to 0.45 mg/kg of dilttazem were superior to that in the placebo group (p 80?6 of ca~es.i-~However, becauseof verapamil’s negative inotropic and vasodilator effects, profound hypotension and even cardiac arrest may occasionally complicate its use.*-12Diltiazem is a calcium antagonist with electrophysiologic effects similar to those of verapamil, but with minimal negative inotropic potential and possibly less hypotensive effect.11J3-19 It has been used intravenously to convert SVT to sinus rhythm, with an overall efficacy of 90% in varying doses and schedules.20This multicenter, randomized, doubleblinded, placebo-controlled,doseranging study was performed to determine the safety and efficacy of intravenous diltiazem for the acute conversionof induced SVT in the setting of diagnostic electrophysiologic testing.
A
MISHODS Study patkntar In all, 170 patients with clinical history of paroxysmal SVT were screenedfor eligibility; 87 entered and completed the study. Inclusion required induction of SVT with programmed stimulation during formal electrophysiologictesting. Eligible SVT was required to have a rate of I1 20 beats/mm and to persist for 115 minutes. Patients with severecongestiveheart failure, sinus node dysfunction, pregnancy, myocardial infarction within 2 weeksof study, or hypotension (systolic pressure
AND CDNDUCllON DtSTUR6ANCES
Acute Conversion of Paroxysmal Supraventricular Tachycardia with Intravenous Diltiazem Anne Hamilton Dougherty, MD, Warren M. Jackman, MD, Gerald V. Naccarelli, MD, Karen J. Friday, MD, and Virgil C. Dias, PharmD, for the IV Diltiazem Study Group Dfltiazem has electrophysiologic effects similar to those of verapamil. Its efftcacy and safety in 4 doses for treatment of induced supraventricutar tachycardia (SVT) were examined and compared with those of placebo in 87 patients (25 with atrtoventricular [AV] nodal reentry tachycardia, 60 with AV reentry associated with an accessory AV connection, and 2 with atrial tachycardia). Conversion to sinus rhythm occurred in 4 of 14 patients (29%) with 0.05 mg/kg of dlttiaxem, 16 of 19 (64%) with 0.15 mg/kg, 13 of 13 (100%) with 0.25 mg/kg, and 14 of 17 (62%) with 0.45 mg/kg compared with 6 of 24 (25%) treated with placebo. Converston rates in groups recetving doses of 0.15 to 0.45 mg/kg of dilttazem were superior to that in the placebo group (p 80?6 of ca~es.i-~However, becauseof verapamil’s negative inotropic and vasodilator effects, profound hypotension and even cardiac arrest may occasionally complicate its use.*-12Diltiazem is a calcium antagonist with electrophysiologic effects similar to those of verapamil, but with minimal negative inotropic potential and possibly less hypotensive effect.11J3-19 It has been used intravenously to convert SVT to sinus rhythm, with an overall efficacy of 90% in varying doses and schedules.20This multicenter, randomized, doubleblinded, placebo-controlled,doseranging study was performed to determine the safety and efficacy of intravenous diltiazem for the acute conversionof induced SVT in the setting of diagnostic electrophysiologic testing.
A
MISHODS Study patkntar In all, 170 patients with clinical history of paroxysmal SVT were screenedfor eligibility; 87 entered and completed the study. Inclusion required induction of SVT with programmed stimulation during formal electrophysiologictesting. Eligible SVT was required to have a rate of I1 20 beats/mm and to persist for 115 minutes. Patients with severecongestiveheart failure, sinus node dysfunction, pregnancy, myocardial infarction within 2 weeksof study, or hypotension (systolic pressure
