[An intrapatient comparison of adaptation to aerobic and anaerobic exertion during 3 types of physiological cardiac stimulation in chronotropic failure of the sinus node: DDD, VVIR and DDDR].
In sick sinus syndrome with chronotropic incompetence, dual-demand rate responsive pacing (DDDR) may be better than ventricular-inhibited rate responsive pacing (VVIR) and dual-demand pacing without rate responsive function (DDD). In order to compare exercise performance during different activity-driven pacing modes, 15 patients (9 males, 6 females; mean age 59 +/- 13 years), implanted with Synchrony 2020T pacemaker (Siemens-Pacesetter Inc, USA, activity sensor) for sick sinus syndrome, randomly performed 3 treadmill tests (modified Bruce protocol) during DDD, VVIR and DDDR pacing, with pacing heart rate, oxygen consumption (Q-Plex 5000, Quinton), work time, anaerobic threshold and human atrial natriuretic peptide level monitoring. Four patients were excluded from the data results (3 for normalization of chronotropic incompetence, 1 for angina pectoris during rate responsive pacing). Heart rate at the end of exercise was significantly higher during VVIR pacing mode (131 +/- 21 b/min) and DDDR (136 +/- 14 b/min) than during DDD pacing mode (105 +/- 21 b/min), p < 0.05. During DDDR we obtained a significantly higher work tolerance (652 +/- 161 s) and a higher oxygen uptake (22.7 +/- 7.1 ml/kg/min) than during DDD (565 +/- 106 s; 20.1 +/- 6.5 ml/kg/min) and VVIR (599 +/- 155 s; 18.8 +/- 6.5 ml/kg/min), p < 0.05. Also the work time and the oxygen uptake at anaerobic threshold were better during DDDR stimulation (350 +/- 119 s; 14.2 +/- 4.9 ml/kg/min) than during DDD (280 +/- 101 s; 12.2 +/- 4.6 ml/kg/min) and VVIR pacing mode (306 +/- 122 s; 11.6 +/- 4.60 ml/kg/min), p < 0.05. On the contrary, human atrial natriuretic factor values at the maximum exercise were lower during DDD (139 +/- 100 pg/ml) than VVIR (256 +/- 182 pg/ml) and DDDR (209 +/- 195 pg/ml) pacing mode, p < 0.05. In conclusion, DDDR pacing proved to be better than VVIR and DDD in patients with sick sinus disease and chronotropic incompetence.
Occhetta
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Cattedra e Divisione Clinicizzata di Cardiologia, Facoltà di Medicina e Chirurgia, Università degli Studi, Torino--sede di Novara.
Perucca
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A
Fazzari
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Pistis
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Baduini
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Trevi
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D000222:Adaptation, Physiological; D000328:Adult; D000368:Aged; D015308:Anaerobic Threshold / Q000502:physiology*; D002304:Cardiac Pacing, Artificial / Q000379:methods* / Q000706:statistics & numerical data; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012804:Sick Sinus Syndrome / Q000503:physiopathology* / Q000628:therapy