Benefit of Single Setting Rate Responsive Ventricular Pacing Compared with Fixed Rate Demand Pacing in Elderly Patients MICHAEL GAMMAGE, STEPHEN SGHOFIELD,* IAN RANKIN,* MARTIN BENNETT, PAULA GOLES. and BRIAN PENTEGOST From the Department of Cardiology. General Hospital. Birmingham; and *Medtronic Pacing Products. Watford, United Kingdom GAMMAGE, M., ET AL: 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 siinpJe, single setting rate response option to VVI pacing, 12 patients (mean age 75.1 ± 6.2, range 62-83 years, seven maJes, five females) with symptomatic complete heart block were entered into a double-hiind, randomized cross- over triaJ of VVI versus VVIR fsingJe setting rate responsive) pacing using Medtronic Activitrax pace- makers. 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, noninciined 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 ±SD1(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 treadmiJl 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 Jess in WIR 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 elderjy patients with symptomatic heart block. This would be a beneficial addition to most limited and multiprogrammable WI systems for use in the elderly. fPACE, Vol. 14, February, Part I 1991) Introduction A number of randomized, double-blind, crossover studies have demonstrated clearly that rate responsive pacing offers significant improve- ment in exercise-related symptoms and exercise capacity,^"^ with a more marked improvement being evident between VVI and VVIR as compared to DDD and DDDR pacing.^ This has resulted in an increase in the implantation rate of VVIR sys- tems throughout the world [around 16% in Address for reprints: Dr M.D. Gammage. Dept, of Cardiovas- cular Medicine, University of Birmingham and Queen Eliza- beth Hospital. Edgbaston, Birmingham B15 2TH, United King- dom. Fax.: 021-414-1045, Received November 6, 1990; accepted November 30. 1990. although surprising numbers of standard VVI sys- tems continue to be implanted. This may relate to the higher cost of VVIR compared to VVI gener- ators but may also result from the concern regard- ing follow-up time needed to program these units for optimum benefit.^ As a result of these real or imagined problems, rate responsive pacemakers are often reserved for younger, more active pa- tients and while many studies have included older patients,^ none has examined the elderly as a spe- cific group in order to assess the potential benefit of rate response in this largest part of the pacing population. In addition, most studies have ex- amined the effect of rate responsive pacing on hemodynamics^ or maximal exercise capacity^'^'^ over varying periods of time despite the fact that these parameters may have little relevance to the 174 February 1991, Parti PAGE, Vol. 14