title: P wave dispersion on 12-lead electrocardiography in adolescents with neurocardiogenic syncope.
abstract: OBJECTIVE
  Neurocardiogenic syncope (NCS) is the most frequent cause of fainting during adolescence. Inappropriate cardiovascular autonomic control may be responsible for this clinical event. The head-up tilt test has been considered a diagnostic standard, but it is cumbersome and has a high false-positive rate. We performed a study to evaluate whether P-wave dispersion (PWD) could be a useful electrocardiographic parameter of cardiac autonomic dysfunction in children with NCS.
  
  
  METHODS
  Fifty-four patients with NCS (28 boys and 26 girls; mean age, 12.3±1.4 years) and 55 age- and sex-matched healthy controls were enrolled. PWD was obtained as the difference between maximum and minimum durations of the P wave on standard 12-lead electrocardiography in all patients and controls.
  
  
  RESULTS
  The value of PWD was significantly higher in the syncope group than in the control group (69.7±19.6 msec vs. 45.5±17.1 msec, respectively;P<0.001). The minimum duration of P wave was shorter in the syncope group than in the control group (43.8±16.8 msec vs. 53.5±10.7 msec, respectively;P<0.001). Left atrial volume was not different between the groups on transthoracic echocardiography.
  
  
  CONCLUSIONS
  PWD on echocardiography could be used as a clinical parameter in patients with NCS.
authors.affiliation: Department of Pediatrics, Konyang University College of Medicine, Daejeon, Korea.
authors.forename: Dong-Hyuk
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Konyang University College of Medicine, Daejeon, Korea.
authors.forename: Kyung-Min
authors.initials: KM
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Konyang University College of Medicine, Daejeon, Korea.
authors.forename: Jung-Min
authors.initials: JM
authors.lastname: Yoon
authors.affiliation: Department of Pediatrics, Konyang University College of Medicine, Daejeon, Korea.
authors.forename: Jae-Woo
authors.initials: JW
authors.lastname: Lim
authors.affiliation: Department of Pediatrics, Konyang University College of Medicine, Daejeon, Korea.
authors.forename: Kyung-Ok
authors.initials: KO
authors.lastname: Kho
authors.affiliation: Department of Pediatrics, Chungnam National University College of Medicine, Daejeon, Korea.
authors.forename: Hong-Ryang
authors.initials: HR
authors.lastname: Kil
authors.affiliation: Department of Pediatrics, Konyang University College of Medicine, Daejeon, Korea.
authors.forename: Eun-Jung
authors.initials: EJ
authors.lastname: Cheon
keywords: Autonomic dysregulation; Neurocardiogenic syncope; P wave dispersion