title: Validating optimal function of the closed loop stimulation sensor with high right septal ventricular electrode placement in 'ablate and pace' patients.
abstract: OBJECTIVE
  The study aim was to validate the closed loop stimulation (CLS) vs. accelerometer (ACC) rate-responsive sensors with electrodes placed in the right ventricular high septal (RVHS) or right ventricular apical (RVA) lead positions in patients following 'ablate and pace' therapy for persistent atrial fibrillation.
  
  
  METHODS
  'Ablate and pace' patients were randomised to either RVHS or RVA electrode placement with a dual sensor device. A double-blind crossover study comparing CLS vs. ACC rate-response pacing modes was undertaken. Subjects undertook cardiopulmonary testing with constant workload light exercise followed by a ramp protocol in addition to activity of daily living assessments.
  
  
  RESULTS
  Twenty subjects (14 male; age, 74 +/- 8 years) were studied. Heart rate increase was greater from lying to sitting with ACC. With mental stress, heart rate increase was greater with CLS. Peak heart rates were similar for stair ascent and descent in ACC mode. With CLS mode, however, the peak heart rate was significantly lower for stair descent. There was no difference between modes in mean response time, oxygen deficit, peak VO(2), VO(2) at anaerobic threshold, peak heart rate, total exercise time and total workload. CLS function was equally optimal at both electrode sites.
  
  
  CONCLUSIONS
  CLS rate adaptive pacing is appropriate for 'ablate and pace' patients, and this sensor functions equally well using RVA or RVHS lead positions.
authors.affiliation: Department of Cardiology, Eastbourne General Hospital, East Sussex NHS Trust, Kings Drive, Eastbourne, BN21 2UD, UK. johnsilberbauer@lycos.com
authors.forename: John
authors.initials: J
authors.lastname: Silberbauer
authors.forename: Paul S G
authors.initials: PS
authors.lastname: Hong
authors.forename: Rick A
authors.initials: RA
authors.lastname: Veasey
authors.forename: Nadeem A
authors.initials: NA
authors.lastname: Maddekar
authors.forename: Wasing
authors.initials: W
authors.lastname: Taggu
authors.forename: Nikhil R
authors.initials: NR
authors.lastname: Patel
authors.forename: Guy W
authors.initials: GW
authors.lastname: Lloyd
authors.forename: Neil
authors.initials: N
authors.lastname: Sulke
mesh_terms: D000054:Acceleration; D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods; D017115:Catheter Ablation; D003131:Combined Modality Therapy; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004567:Electrodes, Implanted; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006346:Heart Septum / Q000601:surgery*; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D014159:Transducers; D016896:Treatment Outcome