title: Effect of rate-adaptive pacing on performance and physiological parameters during activities of daily living in the elderly: results from the CLEAR (Cylos Responds with Physiologic Rate Changes during Daily Activities) study.
abstract: OBJECTIVE
  For most elderly pacemaker patients, evaluation of rate-adaptive pacing using treadmill and bicycle tests is impractical and not representative of typical daily activities. This study was designed to compare the performance and physiological response of the closed-loop stimulation (CLS) rate-adaptive sensor to accelerometer (XL) and no rate sensor (DDD) during typical daily activity testing.
  
  
  RESULTS
  Subjects recently implanted with a Cylos pacemaker completed timed activities of daily life testing, which included walking, sweeping, and standing from a seated position. Activity performance and physiological response from each sensor mode was evaluated for subjects requiring ≥80% pacing. Overall, 74 subjects needed ≥80% pacing during at least one test. An increase in the area swept (CLS vs. XL, 1.67 m(2) difference, P = 0.009; CLS vs. DDD, 1.59 m(2) difference, P = 0.025) and a decrease in the prevalence of orthostatic hypotension (OH) after standing 1 min (CLS vs. XL, odds ratio = 0.16, P = 0.006; CLS vs. DDD, odds ratio = 0.18, P = 0.012) was observed in the CLS mode as compared with XL and DDD. No statistical difference in walk distance was observed between CLS and XL or CLS and DDD.
  
  
  CONCLUSIONS
  In acute testing, as compared with XL and DDD, CLS provides a more physiological response during the performance of activities of daily living for subjects with ≥80% pacing. This is clinically reflected in better performance during the sweep test as well as a decrease in the prevalence of OH in our elderly population. Clinicaltrials.gov identifier: NCT00355797.
authors: Ochsner Medical Center, 1514 Jefferson Hwy, New Orleans, LA 70121, USA. fabisamra@ochsner.org
authors: Freddy M
authors: FM
authors: Abi-Samra
authors: Narendra
authors: N
authors: Singh
authors: Benjamin L
authors: BL
authors: Rosin
authors: Jerome V
authors: JV
authors: Dwyer
authors: Crystal D
authors: CD
authors: Miller
mesh_terms: D056044:Actigraphy / Q000379:methods*; D000203:Activities of Daily Living; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory / Q000379:methods*; D009043:Motor Activity; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014481:United States
keywords: Accelerometer; Closed-loop stimulation; Orthostatic hypotension; Rate-adaptive pacing