title: Acute testing of the rate-smoothed pacing algorithm for ventricular rate stabilization.
abstract: We evaluated the capability of a new pacemaker-based rate-smoothing algorithm (RSA) to reduce the irregular ventricular response of AF. RSA prevents sudden decreases in rate using a modified physiological band and flywheel feature. Twelve patients (51 +/- 21 years) with hemodynamically tolerated AF of 4 months to 20 years duration were studied. Atrial and ventricular leads were connected to the external pacemaker device in the electrophysiology laboratory. Consecutive RR intervals during AF were measured at baseline and after ventricular pacing with RSA ON. Ventricular pacing with the rate smoothing algorithm reduced maximum RR intervals (1,207 +/- 299 vs 855 +/- 148 ms, P = 0.0005), with no significant change in the minimum RR interval (401 +/- 55 vs 393 +/- 74 ms, P = 0.292). A small shortening of the mean RR interval (634 +/- 153 vs 594 +/- 135 ms, P = 0.007) was seen with no change in the median RR interval (609 +/- 153 vs 595 +/- 143 ms, P = 0.388). There was a 43% reduction in RR standard deviation (145 +/- 52 vs 82 +/- 28, P = 0.0005), 49% reduction in mean absolute RR interval difference (MAD) (152 +/- 64 vs 77 +/- 34, P = 0.0005) and MAD/mean RR ratio (0.23 +/- 0.05 vs 0.13 +/- 0.04, P = 0.0005). We conclude that rate-smoothed pacing effectively reduces RR variability of AF in the acute setting.
authors.affiliation: London Health Sciences Centre, Ontario, Canada.
authors.forename: J K
authors.initials: JK
authors.lastname: Lee
authors.forename: R
authors.initials: R
authors.lastname: Yee
authors.forename: M
authors.initials: M
authors.lastname: Braney
authors.forename: G
authors.initials: G
authors.lastname: Stoop
authors.forename: M
authors.initials: M
authors.lastname: Begemann
authors.forename: C
authors.initials: C
authors.lastname: Dunne
authors.forename: G J
authors.initials: GJ
authors.lastname: Klein
authors.forename: A D
authors.initials: AD
authors.lastname: Krahn
authors.forename: N M
authors.initials: NM
authors.lastname: Van Hemel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000628:therapy*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D015331:Cohort Studies; D004562:Electrocardiography; D004867:Equipment Design; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012449:Safety; D012815:Signal Processing, Computer-Assisted; D016276:Ventricular Function / Q000502:physiology*