Differentiating junctional tachycardia and atrioventricular node re-entry tachycardia based on response to atrial extrastimulus pacing

J Am Coll Cardiol. 2008 Nov 18;52(21):1711-7. doi: 10.1016/j.jacc.2008.08.030.


Objectives: The purpose of this study was to differentiate non-re-entrant junctional tachycardia (JT) and typical atrioventricular node re-entry tachycardia (AVNRT).

Background: JT may mimic AVNRT. Ablation of JT is associated with a lower success rate and a higher incidence of heart block. Electrophysiologic differentiation of these tachycardias is often difficult.

Methods: We hypothesized that JT can be distinguished from AVNRT based on specific responses to premature atrial complexes (PACs) delivered at different phases of the tachycardia cycle: when a PAC is timed to His refractoriness, any perturbation of the subsequent His indicates that anterograde slow pathway conduction is involved and confirms a diagnosis of AVNRT. A PAC that advances the His potential immediately after it without terminating tachycardia indicates that retrograde fast pathway is not essential for the circuit and confirms a diagnosis of JT. This protocol was tested in 39 patients with 44 tachycardias suggesting either JT or AVNRT based on a short ventriculo-atrial interval and apparent AV node dependence. Tachycardias were divided into 3 groups: clinically obvious AVNRT, clinically obvious JT, and clinically indeterminate rhythm.

Results: In the 26 cases of clinically obvious AVNRT, the sensitivity and specificity of the test were 61% and 100%, respectively. In the 9 cases of clinically obvious JT, the sensitivity and specificity were 100% and 100%, respectively. In the 9 cases of clinically indeterminate rhythm, the technique indicated AVNRT in 1 patient and JT in 7 patients, and the test was indeterminate in 1 patient.

Conclusions: The response to PACs during tachycardia can distinguish JT and AVNRT with 100% specificity in adult patients.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Cardiac Pacing, Artificial / methods*
  • Cardiac Pacing, Artificial / mortality
  • Catheter Ablation / methods
  • Catheter Ablation / mortality
  • Cohort Studies
  • Diagnosis, Differential
  • Electrocardiography*
  • Electrophysiologic Techniques, Cardiac / methods
  • Female
  • Follow-Up Studies
  • Heart Conduction System / physiopathology
  • Humans
  • Male
  • Middle Aged
  • Risk Assessment
  • Sensitivity and Specificity
  • Severity of Illness Index
  • Survival Analysis
  • Tachycardia, Atrioventricular Nodal Reentry / diagnosis*
  • Tachycardia, Atrioventricular Nodal Reentry / mortality
  • Tachycardia, Atrioventricular Nodal Reentry / surgery*
  • Tachycardia, Ectopic Junctional / diagnosis*
  • Tachycardia, Ectopic Junctional / mortality
  • Tachycardia, Ectopic Junctional / surgery*
  • Treatment Outcome