title: Left atrial conduction along the coronary sinus during ectopic atrial tachycardia and atrial fibrillation: a study using correlation function analysis.
abstract: BACKGROUND
  Correlation function analysis was applied to endocardial electrograms to investigate conduction patterns along the coronary sinus (CS) during sinus rhythm (SR) and atrial tachycardias.
  
  
  RESULTS
  Eighteen recordings were obtained from 14 patients with supraventricular tachycardias. Five atrial fibrillation (AF) recordings were compared to 10 SR recordings and 3 ectopic atrial tachycardia (EAT) recordings. The maximum correlation coefficient was used to assess similarity between signals, i.e., if they originate from the same wavefront. The cumulative time delay, calculated as pairwise summation of interelectrode time delays, was used as an indicator of activation sequence along the CS. Method validation using SR showed right-to-left conduction with high correlations in 8 of 10 recordings indicating one single wavefront. EAT recordings showed consistent left-to-right conduction with left atrial foci and right-to-left with right atrial focus and lower correlations than SR. All 5 AF recordings showed predominantly left-to-right conduction direction, also with correlations lower than SR.
  
  
  CONCLUSIONS
  (1) Correlation function analysis can be used to assess agreement between signals and direction of activation spread. (2) Due to the position of CS, the results can be used to derive mechanisms of interatrial conduction. (3) Consistency in electrical activity propagation along CS is common in AF.
authors.affiliation: Department of Cardiology, University Hospital, Lund University, Lund, Sweden. Jonas.Carlson@kard.lu.se
authors.forename: Jonas
authors.initials: J
authors.lastname: Carlson
authors.forename: Susana
authors.initials: S
authors.lastname: Santos
authors.forename: Pyotr G
authors.initials: PG
authors.lastname: Platonov
authors.forename: Ole Kongstad
authors.initials: OK
authors.lastname: Rasmussen
authors.forename: Rolf
authors.initials: R
authors.lastname: Johansson
authors.forename: S Bertil
authors.initials: SB
authors.lastname: Olsson
mesh_terms: D000465:Algorithms; D001281:Atrial Fibrillation / Q000503:physiopathology*; D004562:Electrocardiography; D006321:Heart / Q000502:physiology*; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D016014:Linear Models; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012815:Signal Processing, Computer-Assisted; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000503:physiopathology; D013612:Tachycardia, Ectopic Atrial / Q000503:physiopathology*