title: P wave signal averaged electrocardiography in patients undergoing the Fontan operation.
abstract: OBJECTIVE
  Supraventricular arrhythmias are one of the most common and fatal sequelae of the Fontan operation. P wave triggered signal averaged electrocardiography was performed in patients undergoing the Fontan operation to evaluate the presence of atrial degeneration, and to clarify which factors affected the development of atrial arrhythmias.
  
  
  METHODS
  P wave triggered signal averaged electrocardiography was recorded in 14 patients after the Fontan-type operation (conventional atriopulmonary connection in 5 and total cavopulmonary connection in 9) and 15 healthy controls. The duration and area of the filtered P wave, and the signal magnitudes (M20, M30) at 20 Hz and 30 Hz obtained from the frequency domain analysis of the P wave (M20, M30) were evaluated and compared with the hemodynamic data.
  
  
  RESULTS
  The duration and area of the filtered P wave, M20 and M30 in patients after atriopulmonary connection were significantly greater than in those after total cavopulmonary connection and the control subjects (p < 0.05). M20 was significantly greater in patients after total cavopulmonary connection than in the control subjects. Right atrial volume in patients after atriopulmonary connection was significantly (p < 0.001) larger than in patients after total cavopulmonary connection (p < 0.05). There were no significant differences in other indices including atrial pressure between the two groups.
  
  
  CONCLUSIONS
  Our results suggest that the substrate for atrial arrhythmias such as atrial myocardial degeneration and fibrosis is frequently present in patients after the Fontan operation, especially after atriopulmonary connection. Thus, the enlarged right atrium may be involved in the presence of a substrate for atrial arrhythmias. The developmental risk for late atrial arrhythmias seems to be present even in patients after total cavopulmonary connection.
authors.affiliation: Department of Developmental Medicine (Pediatrics), Osaka University Graduate School of Medicine, Osaka.
authors.forename: Noboru
authors.initials: N
authors.lastname: Inamura
authors.forename: Tohru
authors.initials: T
authors.lastname: Matsushita
authors.forename: Masatake
authors.initials: M
authors.lastname: Fukunami
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Sano
authors.forename: Makoto
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Shunji
authors.initials: S
authors.lastname: Kurotobi
authors.forename: Takuya
authors.initials: T
authors.lastname: Miura
authors.forename: Hikaru
authors.initials: H
authors.lastname: Matsuda
authors.forename: Shintaro
authors.initials: S
authors.lastname: Okada
mesh_terms: D000293:Adolescent; D001281:Atrial Fibrillation / Q000175:diagnosis; D002648:Child; D004562:Electrocardiography; D005260:Female; D018729:Fontan Procedure / Q000379:methods*; D006330:Heart Defects, Congenital / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D011184:Postoperative Period; D012306:Risk