title: A novel manoeuvre for discerning supraventricular tachycardia mechanism.
abstract: OBJECTIVE
  Discerning supraventricular tachycardia (SVT) mechanism during catheter ablation procedures can be difficult and time-consuming, which, when combined with diagnostic error, places patients at risk of unnecessary complications. Distinguishing atrial tachycardia (AT) from AV nodal re-entry tachycardia (AVNRT) may be particularly vexatious. Value-added techniques are thus always welcome, particularly if they are not time-consuming nor require complex intracardiac lead configurations. In this study, we assessed whether a new technique, simultaneous right atrial and right ventricular pacing (RA + RV) during ongoing SVT, met these criteria.
  
  
  RESULTS
  Using a simple intracardiac lead configuration (right atrial appendage, His bundle, right ventricular apex), the response to RA + RV delivered at 80-90% of the SVT cycle length, was examined in 80 patients referred for catheter ablation. In each patient, the actual tachycardia mechanism was adjudicated by standard electrophysiologic criteria ± successful catheter ablation. Mechanisms of SVT included, non-exclusively, AVNRT (24 patients), accessory pathway-mediated (orthodromic) re-entry (AVRT; 23 patients), AT (10 patients), and sinus tachycardia (ST induced with isoproterenol; 49 patients). Immediately after cessation of RA + RV pacing during persistent SVT, the first intracardiac electrogram observed was right atrial in all AT whereas it was His bundle in all AVNRT. The response during AVRT was mixed.
  
  
  CONCLUSIONS
  In this preliminary evaluation, RA + RV pacing appears to add value to the existing armamentarium of electrophysiologic indices to discern SVT mechanism, in particular with respect to discriminating between AVNRT and AT.
authors.affiliation: Cardiac Electrophysiology Section of the Cardiovascular Institute, University of Pittsburgh Medical Center, 200 Lothrop Street, UPMC Presbyterian, Suite B 535, Pittsburgh, PA 15213, USA. sabas@upmc.edu
authors.forename: Samir
authors.initials: S
authors.lastname: Saba
authors.forename: Sanjoy
authors.initials: S
authors.lastname: Bhattacharya
authors.forename: Ure
authors.initials: U
authors.lastname: Mezu
authors.forename: Eathar
authors.initials: E
authors.lastname: Razak
authors.forename: G Stuart
authors.initials: GS
authors.lastname: Mendenhall
authors.forename: Evan
authors.initials: E
authors.lastname: Adelstein
authors.forename: Sandeep
authors.initials: S
authors.lastname: Jain
authors.forename: William
authors.initials: W
authors.lastname: Barrington
authors.forename: David
authors.initials: D
authors.lastname: Schwartzman
mesh_terms: D000328:Adult; D000368:Aged; D016280:Atrial Function, Right / Q000502:physiology; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D017115:Catheter Ablation; D003937:Diagnosis, Differential; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000175:diagnosis* / Q000503:physiopathology; D013612:Tachycardia, Ectopic Atrial / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D013617:Tachycardia, Supraventricular / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D016278:Ventricular Function, Right / Q000502:physiology