Multicenter Study of Antiarrhythmic Medications for Treatment of Infants With Supraventricular Tachycardia
Condition: Supraventricular Tachycardia
MeSH terms: Tachycardia; Tachycardia, Supraventricular
Intervention: Digoxin; Propranolol
Intervention MeSH terms: Propranolol; Digoxin
Phase: Phase 3
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Enrollment: 72.0
Sex: All
Maximum age: 4 Months
Healthy volunteers: No

Summary:

      This is a randomized, double-blind, multi-centered study to compare 6 months of medical
      treatment with digoxin or propranolol in infants with SVT Background: SVT is the most common
      sustained arrhythmia of infancy. Neither digoxin nor propranolol has been evaluated for
      pediatric use in a controlled trial in the context of SVT, yet both medications are used
      frequently.

      Specific aims of the study:

      To determine whether propranolol and digoxin differ in the:

        1. Incidence of recurrent SVT in infants after 6 months of treatment with propranolol or
           digoxin

        2. Time to first recurrence of SVT in infants treated with propranolol or digoxin.

        3. Incidence of adverse outcomes in infants treated with propranolol or digoxin.
    

Eligibility criteria:

        Inclusion Criteria:

          1. Presentation with SVT due to AVRT or AVNRT.

          2. Age 4 months or less at presentation.

          3. No major structural heart disease (patent foramen ovale and patent ductus arteriosus
             are allowable.

          4. No other significant co-morbid condition likely to result in non-compliance or death
             in next 6 months.

        The SVT mechanism will be presumed to be AVRT or AVNRT if the ECG shows:

          -  Normal complex tachycardia with abrupt onset and offset;

          -  The RR interval remains relatively constant during tachycardia with heart rates of
             220-310 bpm;

          -  VA (ventriculo-atrial) association [i.e., there is a 1:1 AV relationship (except for
             cases of proven AV nodal reentry with a 2:1 relationship between atrium and
             ventricle)]; and

          -  Termination of tachycardia with vagal maneuvres or adenosine with AV block or VA
             block.

        Additional supportive information:

          -  The presence of a P wave in either the ST segment or T wave, or the presence of a P
             wave altering the terminal portion of the QRS complex;

          -  Spontaneous termination of the tachycardia with a P wave;

          -  Onset with prolongation of the PR interval;

          -  Altered rate with resolution of temporary bundle branch block;

          -  Esophageal or electrophysiology study confirming tachycardia mechanism.

        Exclusion Criteria:

          1. Failure to obtain consent;

          2. Known hypersensitivity to either study medication or suspension;

          3. Structural heart disease other than a patent foramen ovale or patent ductus
             arteriosus;

          4. Persistent abnormal cardiac function documented by echocardiogram (shortening fraction
             <28%) in sinus rhythm;

          5. Pre-excitation (Wolff Parkinson White syndrome);

          6. Permanent junctional reciprocating tachycardia;

          7. Ectopic atrial tachycardia;

          8. Atrial flutter;

          9. Sick sinus syndrome or significant bradycardia;

         10. Long QT syndrome;

         11. Digoxin > 40 micrograms/kg total received within past 7 days

         12. Amiodarone >50 milligrams/kg total received within past month

         13. Asthma or obstructive airway disease;

         14. Renal failure.