title: Electrophysiological effects of biatrial pacing evaluated by means of signal-averaged P wave time-domain parameters. The significance of persistent atrial late potentials in right atrium during biatrial pacing.
abstract: BACKGROUND
  Atrial conduction disturbances are a known substrate of re-entrant atrial arrhythmia, and their detection is important for the selection of proper therapy. Time-domain analysis of P-wave in signal-averaged ECG (SA-ECG) recorded from chest leads is an accepted method evaluating inhomogeneity of atrial excitation, predictive for atrial arrhythmias. Biatrial (BiA) pacing created a new therapeutic option for patients with atrial arrhythmias. The aim of our study was to estimate the effect of BiA pacing on SA-ECG recorded from conventional external and from intraatrial leads.
  
  
  METHODS
  Recordings were performed on 24 patients during BiA pacing system implantation. A surface SA-ECG was obtained from orthogonal leads, and intraatrial signals were recorded and averaged separately from the right and left atria at sinus rhythm and BiA pacing. We analyzed standard SA-ECG parameters (P/A wave duration, RMS20 and LAS5) and the presence of atrial late potentials (ALP-Pdur > 125 ms and RMS20 < 2.40 mV).
  
  
  CONCLUSIONS
  BiA pacing favorably modifies SA-ECG parameters in the right and left atrium. BiA pacing significantly shortens P duration, significantly increases RMS20 and reduces atrial late potentials (ALP) occurrence in most patients in comparison to sinus rhythm both atria. ALP are still present in 46% of patients in spite of effective BiA pacing, which can be observed mainly in the right atrium and is connected with increased risk of atrial fibrillation recurrence. This phenomenon suggests a limited effect of RAA-based BiA pacing on the synchrony of atrial activation, and a search is needed for another right atrial lead location for permanent BiA pacing.
authors.affiliation: Department of Cardiology, Medical University of Lublin, Poland. a_kutarski@yahoo.com
authors.forename: Andrzej
authors.initials: A
authors.lastname: Kutarski
authors.forename: Andrzej
authors.initials: A
authors.lastname: Głowniak
authors.forename: Dorota
authors.initials: D
authors.lastname: Szcześniak
authors.forename: Piotr
authors.initials: P
authors.lastname: Ruciński
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000503:physiopathology*; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial