title: Pacemaker prevention therapy in drug-refractory paroxysmal atrial fibrillation: reliability of diagnostics and effectiveness of prevention pacing therapy in Vitatron selection device.
abstract: BACKGROUND
  Atrial fibrillation (AF), the most common and rising disorder of cardiac rhythm, is quite difficult to control and/or to treat. Non pharmacological therapies for AF may involve the use of dedicated pacing algorithms to detect and prevent atrial arrhythmia that could be a trigger for AF onset. Selection 900E/AF2.0 Vitatron DDDRP pacemaker (1) keeps an atrial arrhythmia diary thus providing detailed onset reports of arrhythmias of interest, (2) provides us data about the number of premature atrial contractions (PACs) and (3) plots heart rate in the 5 minutes preceding the detection of an atrial arrhythmia. Moreover, this device applies four dedicated pacing therapies to reduce the incidence of atrial arrhythmia and AF events.
  
  
  OBJECTIVE
  To analyze the reliability to record atrial arrhythmias and evaluate effectiveness of its AF preventive pacing therapies.
  
  
  METHODS
  We enrolled 15 patients (9 males and 6 females, mean age of 71+/-5 years, NYHA class I-II), with a DDDRP pacemaker implanted for a "bradycardia-tachycardia" syndrome, with advanced atrioventricular conduction disturbances. We compared the number and duration of AF episodes' stored in the device with a contemporaneous 24h Holter monitoring. After that, we switched on the atrial arrhythmias detecting algorithms, starting from an atrial rate over 180 beats per minute for at least 6 ventricular cycles, and ending with at least 10 ventricular cycles in sinus rhythm. Thereafter, in order to evaluate the possible reduction in PACs number and in number and duration of AF episodes, we tailored all the four pacing preventive algorithms. Patients were followed for 24+/-8 months (from 20 to 32 months).
  
  
  RESULTS
  All 59 atrial arrhythmia episodes occurred in the first part of this trial, were correctly recorded by both systems, with a correlation coefficient (r) of 0.96. During the follow-up, we observed a significant reduction not only in PACs number (from 83+/-12/day to 2.3+/-0.8/day) but also in AF episodes (from 46+/-7/day to 0.12+/-0.03/day) and AF burden (from 93%+/-6% to 0.3%+/-0.06%). An increase in atrial pacing percentages (from 3%+/-0.5% to 97%+/-3%) was also contemporaneously observed.
  
  
  CONCLUSIONS
  In this pacemaker, detection of atrial arrhythmia episodes is highly reliable, thus making available an appropriate monitoring of heart rhythm, mainly suitable in AF asymptomatic patients. Moreover, the significant reduction of atrial arrhythmia episodes indicates that this might represent a suitable therapeutic option for an effective preventive therapy of AF in paced brady-tachy patients.
authors.affiliation: Divisione di Cardiologia, Azienda Ospedaliera Luigi Sacco - Polo Universitario, Istituto di Scienze Biomediche LITA, University of Milan, Italy. terranovapaolo@hotmail.com
authors.forename: Paolo
authors.initials: P
authors.lastname: Terranova
authors.forename: Paolo
authors.initials: P
authors.lastname: Valli
authors.forename: Peppino
authors.initials: P
authors.lastname: Terranova
authors.forename: Simonetta
authors.initials: S
authors.lastname: Dell'Orto
authors.forename: Enrico Maria
authors.initials: EM
authors.lastname: Greco