Dexmedetomidine and Adenosine: Therapeutic Use for SVT

Not Applicable

Completed

Brief Summary: The purpose of this study is to evaluate the efficacy and safety of dexmedetomidine in the acute termination of Supraventricular Tachycardia (SVT).

Detailed Description: In 2006 the investigator found that dexmedetomidine, an alpha-2 adrenergic agonist with primarily sedative properties, possesses additional anti-arrhythmic properties. So far the investigator has found that dexmedetomidine has the ability to prevent or terminate arrhythmias like atrial ectopic tachycardia (85% success) and junctional ectopic tachycardia (75% success). The most dramatic effect however was observed in the acute termination of reentrant SVT with a success rate of \> 96%. More importantly we found that dexmedetomidine terminates SVT without causing any sinus pause or asystole (frequently seen with adenosine) and thus avoiding the feeling of "impending doom". In this study adenosine is being compared head to head with dexmedetomidine in a cross over study, for both safety and efficacy when given for the termination of SVT in the electrophysiology (EP) lab. Additional EP parameters will be measured to elucidate the exact site of dexmedetomidine's mechanism of action.

Recruitment & Eligibility

Inclusion Criteria

Patients between the age of 5 - 30 years old, who are scheduled for cardiac electrophysiology study for evaluation of reentrant SVT

Exclusion Criteria

Severe Heart Failure
Presence of of any other antiarrhythmic medication within 24 hours of enrollment
Third degree heart block
Sick Sinus Syndrome

Arm && Interventions

Group	Intervention	Description
Adenosine and Dexmedetomidine	Dexmedetomidine	Patients will receive adenosine and then dexmedetomidine for the termination of SVT
Adenosine and Dexmedetomidine	Adenosine	Patients will receive adenosine and then dexmedetomidine for the termination of SVT

Primary Outcome Measures

Name	Time	Method
Termination of SVT	Within 3 minutes	Number of participants with SVT Termination within 3 minutes of medication administration

Secondary Outcome Measures

Name	Time	Method
Number of Participants With Sinus Pause >2.5 Sec After Termination of SVT	1 minute	Evaluation of the number of participants with sinus pause \> 2.5 sec, after dexmedetomidine vs. adenosine induced SVT termination
Number of Participants With Tachyarrhythmias After Medication Administration	10 minutes	Number of participants with tachyarrhythmias, including Ventricular (Ventricular Tachycardia \& Fibrillation)and supraventricular (Atrial Flutter \& Fibrillation) after dexmedetomidine vs. adenosine administration
Number of Participants With Hypotension by Non-invasive Cuff in First 10 Minutes After Medication Administration	10 minutes	Blood pressure changes after dexmedetomidine vs. adenosine. Blood pressure measured by non-invasive cuff prior to medication administration, and then at 1 min, 3 min, 5 min after medication administration. Number of participants with a significant drop in blood pressure (mmHg) compared to baseline would be counted for hypotension.