title: Global P wave duration on the 65-lead ECG: single-site and dual-site pacing in the structurally normal human atrium.
abstract: BACKGROUND
  Pacing is believed to prevent atrial fibrillation by reducing atrial activation time. Exact correlation between P wave duration (PWD) on surface ECG and endocardial atrial activation time is still unexplored.
  
  
  RESULTS
  In 15 patients without structural heart disease (9 women, age 45 +/- 14 years), single site [high right atrium (HRA), coronary sinus ostium (CSos), distal CS (CSd), high RA septum (Bachmann's bundle, BB)] and dual-site pacing (various combinations) was performed after ablation of supraventricular tachycardia. A 65-lead surface ECG was recorded simultaneously. Endocardial atrial activation time was measured off-line (stimulus - last bipolar recording), and the respective PWD was assessed using the root mean square and 65-channel summary plots. PWD during pacing from BB was significantly shorter (96 +/- 12 msec) than during HRA (121 +/- 15 msec), CSos (108 +/- 9 msec), and CSd pacing (126 +/- 14 msec; P < 0,01, respectively). PWD during dual-site pacing (HRA+BB, 91 +/- 14 msec; HRA+CSos, 96 +/- 7 msec; HRA+CSd, 90 +/- 7 msec; BB+CSd, 96 +/- 12 msec) was not significantly shorter than during pacing from BB. Correlation between endocardial atrial activation time and PWD was 0.83.
  
  
  CONCLUSIONS
  PWD during single-site and dual-site atrial pacing represents endocardial atrial activation time and can be measured precisely using the 65-lead surface ECG. The fact that high septal pacing results in the shortest PWD may have implications for preventive pacing in patients with atrial fibrillation.
authors.affiliation: Department of Clinical Cardiology, University Hospital Innsbruck, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Gozolits
authors.forename: Gerald
authors.initials: G
authors.lastname: Fischer
authors.forename: Thomas
authors.initials: T
authors.lastname: Berger
authors.forename: Fritz
authors.initials: F
authors.lastname: Hanser
authors.forename: Maria
authors.initials: M
authors.lastname: Abou-Harb
authors.forename: Bernhard
authors.initials: B
authors.lastname: Tilg
authors.forename: Otmar
authors.initials: O
authors.lastname: Pachinger
authors.forename: Florian
authors.initials: F
authors.lastname: Hintringer
authors.forename: Franz X
authors.initials: FX
authors.lastname: Roithinger
mesh_terms: D000328:Adult; D016275:Atrial Function; D002304:Cardiac Pacing, Artificial / Q000379:methods; D004562:Electrocardiography / Q000295:instrumentation; D004699:Endocardium / Q000503:physiopathology; D004867:Equipment Design; D005260:Female; D006346:Heart Septum / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011930:Reaction Time; D013617:Tachycardia, Supraventricular / Q000503:physiopathology / Q000628:therapy*