Benefit of Single Setting Rate Responsive Ventricular Pacing Compared with Fixed Rate Demand Pacing in Elderly Patients

In order to assess the value of a simple, single setting rate response option to VVI pacing, 12 patients (mean age 75.1 ± 6,2, range 62–83 years, seven males, five females) with symptomatic complete heart block were entered into a double-blind, randomized crossover trial of VVI versus VVIR (single setting rate responsive) pacing using Medtronic Activitrax pacemakers. Assessment was by time taken in seconds (sec) and Borg scale symptom score (6–20) for simple activities (standing from chair x 30; walking 800 meters; 52 steps on stairs slow and fast pace], and incremental, noninclined maximal treadmill exercise), performed after a 4-week period with the patient in each pacing mode. Times were significantly improved in VVIR mode for standing from chair mean ± SD] (78.7 ± 22.5 vs 70.7 ± 19.5 sec; P < 0.05), for 800 m walk (1032 ± 80 vs 885 ± 59 sec; P < 0.05), fast ascent of stairs (29.5 ± 7.7 vs 26.5 ± 5.6 sec; P < 0.02), and treadmill exercise (626.7 ± 189.5 vs 741.0 ± 170.2 sec, P < 0.005) although no difference in time for slow stair ascent was demonstrated. Symptom scores were significantly less in VVIR for standing from chair (12.7 ± 2.8 vs 10.3 ± 1.8; P < 0.01), 800 m walk (10.9 ± 2.7 vs 9.0 ± 2.4; P < 0.01), slow ascent of stairs (11.6 ± 2.1 vs 10.0 ± 2.0; P < 0.01), and fast ascent of stairs (13.0 ± 2.0 vs 11.7 ± 1.9; P < 0.02) but unchanged for treadmill exercise. Single setting VVIR pacing increases maximum exercise capacity and decreases perceived difficulty of submaximal exercise in elderly patients with symptomatic heart block. This would be a beneficial addition to most limited and multiprogrammable VVI systems for use in the elderly.