Tachycardia induction with ventricular extrastimuli differentiates atypical atrioventricular nodal reentrant tachycardia from orthodromic reciprocating tachycardia

Heart Rhythm. 2012 Mar;9(3):335-41. doi: 10.1016/j.hrthm.2011.10.015. Epub 2011 Oct 13.

Abstract

Background: Differentiating atypical atrioventricular nodal reentrant tachycardia (AVNRT) from septal orthodromic reentrant tachycardia (ORT(Septal)) is challenging in nonsustained tachycardia. When sustained, the postpacing interval minus tachycardia cycle length following entrainment (PPI(Entrainment) - TCL) and stimulation to atrial interval minus ventriculoatrial interval (Stim-A(Entrainment) - VA) are utilized.

Objective: We hypothesized that the first tachycardia cycle after tachycardia induction with right ventricular apical extrastimulation would yield comparable information to entrainment, precluding the need for sustained tachycardia.

Methods: Twenty-four patients with AVNRT (age 47 ± 18 years), 19 with ORT(Septal) (age 42 ± 17 years), and 15 with ORT over a left lateral accessory pathway (ORT(Left)) (age 41 ± 16 years) were included. The ventricular extrastimulus to atrial depolarization at tachycardia initiation (Stim-A(Initiation)) and tachycardia VA interval were measured to establish the Stim-A(Initiation) minus VA interval (Stim-A(Initiation) - VA). The ventricular extrastimulus to the subsequent right ventricular apical depolarization (postpacing interval at initiation, PPI(Initiation)) was utilized to obtain the PPI(Initiation) minus TCL (PPI(Initiation) - TCL). The AH interval associated with the PPI(Initiation) minus the AH in tachycardia was utilized to establish a corrected PPI(Initiation) minus TCL (cPPI(Initiation) - TCL).

Results: The intervals after tachycardia initiation were longer for AVNRT than for ORT: mean PPI(Initiation) - TCL (193 ± 44 vs 91 ± 73; P <.001), cPPI(Initiation) - TCL (174 ± 44 ms vs 88 ± 50 ms; P <.001), and Stim-A(Initiation) - VA (161 ± 45 ms vs 69 ± 53 ms; P <.001). The correlation coefficient for Stim-A(Initiation) minus VA against Stim-A(Entrainment) minus VA was 0.79 and for cPPI(Initiation) minus TCL against PPI(Entrainment) minus TCL was 0.71. cPPI(Initiation) minus TCL <115 ms or Stim-A(Initiation) - VA <85 ms was observed only in ORT. The converse was observed in AVNRT but also in ORT(Septal) over decremental accessory pathways and ORT(Left).

Conclusion: Stim-A(Initiation) - VA < 85 ms or cPPI(Initiation) - TCL < 115 ms excludes AVNRT.

MeSH terms

  • Accessory Atrioventricular Bundle* / complications
  • Accessory Atrioventricular Bundle* / diagnosis
  • Accessory Atrioventricular Bundle* / physiopathology
  • Adult
  • Aged
  • Diagnosis, Differential
  • Electric Stimulation / methods
  • Electrocardiography / methods
  • Electrophysiologic Techniques, Cardiac / methods*
  • Female
  • Heart Conduction System / physiopathology*
  • Heart Rate
  • Heart Septum / physiopathology*
  • Humans
  • Male
  • Middle Aged
  • Tachycardia, Atrioventricular Nodal Reentry* / diagnosis
  • Tachycardia, Atrioventricular Nodal Reentry* / etiology
  • Tachycardia, Atrioventricular Nodal Reentry* / physiopathology