title: Right atrial modification of maze surgery does not affect refractoriness and conduction patterns of human lone atrial fibrillation.
abstract: BACKGROUND
  Tissue mass and structure are relevant for initiation and persistence of fibrillation. Modification of the right atrium during maze surgery may change the arrhythmogenic substrate of atrial fibrillation (AF).
  
  
  RESULTS
  Epicardial mapping was performed in 9 patients undergoing unmodified maze III surgery for lone paroxysmal AF. Simultaneous recording of AF on the right and left atrium was carried out with two spoon-electrodes each harbouring 64 terminals. Activation maps of AF were made to study AF wavelet organization. The recording position on right and left atria was outside the surgical field and remained unchanged before and after surgery. Before surgery, mean right and left fibrillatory intervals were 174+/-23 ms, and 175+/-26 ms, respectively, and did not differ. After completed right atrial surgery, these fibrillary intervals remained unchanged. Mean right and left atrial dispersion of refractoriness (expressed as the coefficient of variation) were 4.2+/-0.8 and 5.2+/-3.8 ms. Only right atrial dispersion of refractoriness increased significantly after right-sided surgery. Prior to surgery, activation patterns of the left atrium were more complex than that of the right atrium. The left activation patterns became less complex afterwards; the right atrial activation patterns did not change.
  
  
  CONCLUSIONS
  The right atrial modification of maze III surgery neither affects atrial refractoriness during human lone AF nor changes AF wavelet organization. Thus, right atrial surgery does not modify the arrhythmogenic substrate of AF. These findings may imply that maze surgery can be restricted to the left atrium.
authors.affiliation: Departments of Cardiology and Cardio-Thoracic Surgery, St Antonius Hospital, Nieuwegein, The Netherlands.
authors.forename: E R
authors.initials: ER
authors.lastname: Jessurun
authors.forename: J M T
authors.initials: JM
authors.lastname: de Bakker
authors.forename: N M
authors.initials: NM
authors.lastname: van Hemel
authors.forename: T
authors.initials: T
authors.lastname: Opthof
authors.forename: A C
authors.initials: AC
authors.lastname: Linnenbank
authors.forename: P F H M
authors.initials: PF
authors.lastname: van Dessel
authors.forename: J J A M T
authors.initials: JJ
authors.lastname: Defauw
authors.forename: A B
authors.initials: AB
authors.lastname: de la Rivière
mesh_terms: D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D006325:Heart Atria / Q000503:physiopathology / Q000601:surgery*; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged