Junctional tachycardia

Background

  • Rare
  • Cardiac impulses originate at the AV junction
    • AV node
    • Bundle of His
  • Also referred to as Junctional Ectopic Tachycardia (JET) or Congenital Ectopic Tachycardia (CJET) if present at birth
  • Rate exceeds the upper limit seen in normal sinus rhythm

Junction Rhythm Classification

Arbitrarily classified by rate

Clinical Features

  • Clinical features vary widely, diagnosis usually made via ECG
  • Past medical hx may include recent cardiovascular surgery

Differential Diagnosis

Narrow-complex tachycardia

Wide-complex tachycardia

Assume any wide-complex tachycardia is ventricular tachycardia until proven otherwise (it is safer to incorrectly assume a ventricular dysrhythmia than supraventricular tachycardia with abberancy)

^Fixed or rate-related

Evaluation

ECG showing junctional tachycardia. Note narrow complex QRS, no P waves, and accelerated rate.
  • ECG findings
    • P waves
      • may be antegrade, retrograde, or absent depending on depolarization of the atrial relative to the ventricles
    • QRS complexes
      • Narrow in the absence of aberrancy
  • May be distinguished from AVNRT via Adenosine administration
    • If JET is present, atrial depolarization will briefly terminate and reveal AV dissociation
    • If AVNRT is present, conversion to sinus rhythm will likely occur
    • Avoid administration in the setting of aberrancy
    • JET will concomitant 3 degree AVB is rare
  • Consider JET underlying causes to include
    • Electrolyte abnormalities
    • Acidosis
    • Cardiovascular surgery within 24-48 hrs

Management

  • Amiodarone 2 mg/kg bolus.[1]
    • If necessary, as continuous infusion at 10 to 15 mcg/kg/min

See Also

External Links

References

  1. [pubmed.ncbi.nlm.nih.gov/19632422], Kovacikova L. Amiodarone as a First-Line Therapy for Postoperative Junctional Ectopic Tachycardia. PubMed, National Library of Medicine, Aug 30, 2009.