title: Various routes of septal propagation in common atrial flutter.
abstract: BACKGROUND
  Although in the treatment of common atrial flutter, the isthmus between the tricuspid valve annulus and the eustachian ridge is often chosen as the site for conduction block by radiofrequency ablation, the precise path of the flutter circuit remains unknown. We therefore investigated the propagation of the atrial flutter wave front around the coronary sinus ostium and how its path is altered by application of radiofrequency current.
  
  
  RESULTS
  To assess activation pattern, activation in the region surrounding the coronary sinus ostium was mapped using a deflectable decapolar catheter under basal conditions and while applying radiofrequency current to the septal isthmus, between the tricuspid valve annulus and the eustachian ridge. In five of eleven patients studied, the eustachian ridge side, below the coronary sinus ostium, was activated earlier, and the flutter wave exited from either the tricuspid valve annulus side or the eustachian ridge side, above the coronary sinus ostium. In four patients, a partial line of block created by applying radiofrequency current between the tricuspid valve annulus and the coronary sinus ostium or between the coronary sinus ostium and the eustachian ridge led to a shift in the direction of propagation of the flutter wave front from anterior to posterior or from posterior to anterior of the coronary sinus ostium, and prolongation of the cycle length.
  
  
  CONCLUSIONS
  Application of radiofrequency current to the septal isthmus, between the tricuspid valve annulus and the eustachian ridge, can shift both the anterior and posterior propagation of flutter around the coronary sinus ostium.
authors: Department of Internal Medicine, Jikei University School of Medicine, 3-25-8 Nishi-shinbashi, Minato-ku, Tokyo 105-8461, Japan. datet@jikei.ac.jp
authors: Taro
authors: T
authors: Date
authors: Kunihiko
authors: K
authors: Abe
authors: Hidekazu
authors: H
authors: Miyazaki
authors: Teiichi
authors: T
authors: Yamane
authors: Kenichi
authors: K
authors: Sugimoto
authors: Junichi
authors: J
authors: Mogi
authors: Youichi
authors: Y
authors: Honda
authors: Kenji
authors: K
authors: Noma
authors: Shinichiro
authors: S
authors: Ishikawa
authors: Seibu
authors: S
authors: Mochizuki
mesh_terms: D000368:Aged; D001282:Atrial Flutter / Q000503:physiopathology*; D017115:Catheter Ablation; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006331:Heart Diseases / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D014261:Tricuspid Valve / Q000503:physiopathology