title: Does a high percentage of right ventricular pacing influence the incidence of paroxysmal atrial fibrillation in myotonic dystrophy type 1 patients?
abstract: BACKGROUND
  Paroxysmal atrial tachyarrhythmias occur frequently in myotonic dystrophy type 1 (MD1) patients. Pacemakers, implanted for the treatment of bradyarrhythmias and including detailed diagnostic functions, may facilitate the diagnosis and management of frequent paroxysmal atrial fibrillation (AF) that may remain undetected during a conventional clinical follow-up. The effect of right ventricular pacing on AF incidence is still controversial.
  
  
  OBJECTIVE
  To evaluate the influence of a high percentage of right ventricular pacing on AF in MD1 patients during a 12-month follow-up period.
  
  
  METHODS
  We enrolled in the present study 70 MD1 patients (age 51.3 ± 5 years; 32 females) who underwent dual chamber pacemaker implantation. At 12 months of follow-up, the study population was divided into three groups according to the percentage of atrial and ventricular stimulation: Group 1, the atrial sensing ventricular sensing group (ASVS; n = 22; age 52 ± 7.7; eight female) with a percentage of atrial and ventricular stimulation lower than 50%; Group 2, the atrial sensing ventricular pacing group (ASVP; n = 24; age 50.5 ± 7.6; 13 female) with a percentage of atrial stimulation lower than 50% and percentage of ventricular stimulation higher than 80%; and Group 3, the atrial pacing ventricular pacing group (APVP; n = 24; age 56 ± 4.3; 11 female) with a percentage of atrial and ventricular stimulation higher than 80%. We counted the number of episodes of atrial arrhythmia that occurred during the observation period and the duration of each episode.
  
  
  RESULTS
  We found a statistically significant difference in the number and duration of AF episodes between the three groups at the 12-month follow-up. In particular, there were more episodes (253 ± 30 vs. 80 ± 27 vs. 53 ± 32; p < 0.03) and longer durations of AF (8,700 ± 630 vs. 4,480 ± 975 vs. 3,853 ± 870 min; p < 0.03) in the ASVP group than in the ASVS group and the APVP group. Lead parameters remained stable over time and there were no displacements of the electrodes after implantation.
  
  
  CONCLUSIONS
  In a 12-month follow-up comparison, we showed a statistically significant increase in paroxysmal AF episodes in MD1 patients with a high percentage of right ventricular pacing and a lower percentage of atrial stimulation.
authors.affiliation: andreaantoniopapa@libero.it.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Russo
authors.forename: Anna
authors.initials: A
authors.lastname: Rago
authors.forename: Andrea Antonio
authors.initials: AA
authors.lastname: Papa
authors.forename: Luisa
authors.initials: L
authors.lastname: Politano
authors.forename: Paolo
authors.initials: P
authors.lastname: Golino
authors.forename: Maria Giovanna
authors.initials: MG
authors.lastname: Russo
authors.forename: Raffaele
authors.initials: R
authors.lastname: Calabrò
authors.forename: Gerardo
authors.initials: G
authors.lastname: Nigro
mesh_terms: D000465:Algorithms; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy*; D002304:Cardiac Pacing, Artificial / Q000706:statistics & numerical data*; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009223:Myotonic Dystrophy / Q000453:epidemiology*; D013614:Tachycardia, Paroxysmal / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy*