title: [Heart rate variability and vasovagal syncope].
abstract: OBJECTIVE
  Tilt Table testing is widely used for the diagnosis and evaluation of vasovagal syncope. By evaluating the fluctuations of the autonomic nervous system that play an important role in syncope genesis, heart rate variability (HRV) can be considered as a tool of added value.
  
  
  METHODS
  We evaluated prospectively 123 patients admitted for recurrent syncope with a positive tilt Table testing. A time domain analysis of a 24 hours ambulatory electrocardiography was used in all patients to asses the particularities of their autonomic function. We compared their results with those obtained from a group of 82 healthy volunteers.
  
  
  RESULTS
  Statistical analysis of the results showed a significant increase of all HRV parameters in the group of vasovagal syncope compared to the healthy volunteers. SDNNidx (58 vs 42; p < 0.001), rMSSD (40 vs 27; p < 0.001), SDNN (102 vs 83; p < 0.001), SDANN (79 vs 67; p< 0.001), pNN50 (11 vs 4.9; p <0.001).
  
  
  CONCLUSIONS
  Time domain analysis of heart rate variability reveals increased values in patients with vasovagal syncope. It seems to be an interesting, easy and complementary test in the evaluation of syncope of unknown etiology.
authors.affiliation: Service de cardiologie, Hôpital Hôtel-Dieu de France, rue Alfred-Naccache, Beyrouth, Liban. etsalame@hotmail.com
authors.forename: E
authors.initials: E
authors.lastname: Salameh
authors.forename: Z
authors.initials: Z
authors.lastname: Kadri
authors.forename: R
authors.initials: R
authors.lastname: Neemtallah
authors.forename: R
authors.initials: R
authors.lastname: Azar
authors.forename: G
authors.initials: G
authors.lastname: Badaoui
authors.forename: S Abou
authors.initials: SA
authors.lastname: Jaoude
authors.forename: R
authors.initials: R
authors.lastname: Kassab
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D015716:Electrocardiography, Ambulatory; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D013575:Syncope / Q000503:physiopathology*; D018667:Tilt-Table Test