title: Pacemaker prevention therapies for the control of drug-refractory paroxysmal atrial fibrillation.
abstract: OBJECTIVE
  Atrial septal pacing has been shown to prevent paroxysmal atrial fibrillation (PAF) refractory to drugs in patients without inappropriate bradycardia. This study assesses the effects of atrial septal pacing using new pacing algorithms designed to prevent the initiation or maintenance of PAF.
  
  
  RESULTS
  Eleven Medtronic AT500 and 6 Guidant Pulsar Max pacemakers were implanted. The incremental benefit of prevention pacing therapies was compared with DDDR pacing by analysis of pacemaker-stored electrograms, ambulatory electrocardiography, symptoms and quality of life questionnaires.
  
  
  RESULTS
  Atrial septal pacing reduced AF burden by >50% in 13/17 patients (76.5%). Activation of a combined pacing algorithm (atrial pacing preference; atrial rate stabilization; and post mode-switch overdrive pacing) in patients with AT500 pacemakers produced a marginal reduction in AF burden (mean %AF 0.61 ON, 0.73 OFF, P=0.53 ns). Conversely in the Pulsar Max group when atrial pacing preference was activated, AF burden was slightly increased (mean %AF 5.84 ON, 3.73 OFF,P =0.13). Symptoms improved with atrial septal pacing but did not change when prevention algorithms were activated.
  
  
  CONCLUSIONS
  Atrial septal pacing resulted in a marked improvement in AF burden and symptoms. Activation of specific prevention pacing algorithms provided more continuous atrial pacing but had limited and heterogeneous effects on AF burden.
authors.affiliation: Regional Cardiac Centre, Wythenshawe Hospital, Manchester, UK. mkale@onetel.net.uk
authors.forename: M
authors.initials: M
authors.lastname: Kale
authors.forename: D H
authors.initials: DH
authors.lastname: Bennett
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D001281:Atrial Fibrillation / Q000150:complications / Q000503:physiopathology / Q000517:prevention & control*; D018592:Cross-Over Studies; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006346:Heart Septum / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D010138:Pacemaker, Artificial; D011446:Prospective Studies; D011788:Quality of Life; D012720:Severity of Illness Index