title: Ventricular rate-adaptive pacing in the elderly.
abstract: The role of ventricular rate-adaptive pacing (VVIR) in the elderly was investigated in 12 patients with a mean age of 85 +/- 2 years (range 75-95 years) with implanted activity-initiated VVIR pacemakers. Although four patients had significant extracardiac diseases, all were capable of independent walking and self care. The pacing rate achieved during structured daily activities (walking, climbing stairs, washing, bed-making and scrubbing floors) were compared with those achieved by 10 age-matched healthy subjects. Apart from the more strenuous activities (ascending stairs and floor-scrubbing), the pacing rates achieved by the patients were comparable to those of the healthy subjects and occurred within an appropriate time. In a 4-weekly randomized, double-blind crossover protocol in the VVI and VVIR pacing modes, all patients underwent assessments in a 12-min walking distance test, a 24 h non-invasive ambulatory blood pressure recording and a symptomatic documentation. During VVIR pacing, the 12-min walking distance was significantly improved compared to VVI pacing (556 +/- 52 vs. 545 +/- 55 m, P less than 0.05). There was no difference between the recorded blood pressure and symptom scores between the two pacing modes, although most patients preferred VVIR pacing (P less than 0.05). It is concluded that VVIR pacing in this elderly population can improve exercise capacity, and the patients' preference for the VVIR mode was documented despite the absence of a measurable difference in symptomatology.
authors.affiliation: Division of Cardiology, University Department of Medicine, Queen Mary Hospital, University of Hong Kong.
authors.forename: C P
authors.initials: CP
authors.lastname: Lau
authors.forename: C K
authors.initials: CK
authors.lastname: Wong
authors.forename: Y T
authors.initials: YT
authors.lastname: Tai
authors.forename: P C
authors.initials: PC
authors.lastname: Fong
authors.forename: J P
authors.initials: JP
authors.lastname: Li
authors.forename: F L
authors.initials: FL
authors.lastname: Chung
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure / Q000502:physiology; D001919:Bradycardia / Q000503:physiopathology / Q000628:therapy*; D004311:Double-Blind Method; D015716:Electrocardiography, Ambulatory / Q000295:instrumentation; D005080:Exercise Test; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D012984:Software