title: "V-H-A Pattern" as a criterion for the differential diagnosis of atypical AV nodal reentrant tachycardia from AV reciprocating tachycardia.
abstract: BACKGROUND
  During ventricular extrastimulation, His bundle potential (H) following ventricular (V) and followed by atrial potentials (A), i.e., V-H-A, is observed in the His bundle electrogram when ventriculo-atrial (VA) conduction occurs via the normal conduction system. We examined the diagnostic value of V-H-A for atypical form of atrioventricular nodal reentrant tachycardia (AVNRT), which showed the earliest atrial activation site at the posterior paraseptal region during the tachycardia.
  
  
  METHODS
  We prospectively examined the response of VA conduction to ventricular extrastimulation during basic drive pacing performed during sinus rhythm in 16 patients with atypical AVNRT masquerading atrioventricular reciprocating tachycardia (AVRT) utilizing a posterior paraseptal accessory pathway and 21 with AVRT utilizing a posterior paraseptal accessory pathway. Long RP' tachycardia with RP'/RR > 0.5 was excluded. The incidences of V-H-A and dual AV nodal physiology (DP) were compared between atypical AVNRT and AVRT.
  
  
  RESULTS
  V-H-A was demonstrated in all the 16 patients (100%) in atypical AVNRT and in only 1 of the 21 (5%) in AVRT (P < 0.001). DP was demonstrated in 10 patients (63%) in atypical AVNRT and in 4 (19%) in AVRT (P < 0.05). The sensitivity of V-H-A for atypical AVNRT was higher than that of DP (P < 0.05). Positive and negative predictive values were 94% and 100%, respectively, for V-H-A and 71% and 74%, respectively, for DP.
  
  
  CONCLUSIONS
  The appearance of V-H-A during ventricular extrastimulation is a simple criterion for differentiating atypical AVNRT masquerading AVRT from AVRT utilizing a posterior paraseptal accessory pathway.
authors: Second Department of Internal Medicine, Hirosaki University School of Medicine, Hirosaki, Japan.
authors: Shingen
authors: S
authors: Owada
authors: Atsushi
authors: A
authors: Iwasa
authors: Shingo
authors: S
authors: Sasaki
authors: Takumi
authors: T
authors: Higuma
authors: Masaomi
authors: M
authors: Kimura
authors: Takao
authors: T
authors: Kobayashi
authors: Keiichi
authors: K
authors: Ashikaga
authors: Ken
authors: K
authors: Okumura
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002036:Bundle of His / Q000503:physiopathology; D017115:Catheter Ablation; D003937:Diagnosis, Differential; D004558:Electric Stimulation; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000503:physiopathology; D006329:Heart Conduction System / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000175:diagnosis* / Q000601:surgery; D013614:Tachycardia, Paroxysmal / Q000175:diagnosis*