Subjective and Objective Response to Single- Versus Dual-Chamber Pacing

With two different questionnaires, we analyzed the feeling of well-being during dual chamber pacing mode and VVI mode in 25 randomly selected patients, mean age 66.7 years (range 22–84). All patients had high degree AV block and received either a DDD pacemaker (23 patients) or a VDD pacemaker. Under each pacing mode exercise tests were performed as well. Questionnaire 1 was answered during DDD or VDD mode. According to questionnaire 1, 76% of the patients remembered their symptoms before PM implantation. Eighty-two percent of the patients felt an improvement of their symptoms after the installation of the pacemaker. Questionnaire 2 was answered after a three-week period of VVI pacing. Fifty-six of the patients indicated a deterioration of their general conditions, 36% of the patients noted dizziness, 58% dyspnea, 40% reduced effort tolerance, and 22% a sleep disturbance. After a change to dual-chamber pacing, general well-being was better in 74% of the patients, dyspnea was noted in only 15%, effort tolerance was improved in 61%, and sleep was undisturbed in 97%. The physical work capacity (expressed as a product of Watts multiplied by minutes) tested on a bicycle ergometer was 400 ± 190 Wmin in VVI mode and 414 ± 272 Wmin in DDD/VDD mode (p = ns). The double products were 14,600 ± 4,934 and 22,066 ± 5,585 (p < 0.05), respectively. We conclude that dual-chamber pacing leads to a significant improvement in the quality of life for patients with symptomatic AV block.