Capucci A, Boriani G, Specchia S, Marinelli M, Santarelli A, Magnani B
Institute of Cardiovascular Diseases, University of Bologna, Italy.
Pacing Clin Electrophysiol. 1992 Nov;15(11 Pt 2):1908-13. doi: 10.1111/j.1540-8159.1992.tb02992.x.
In eight patients (age 62 +/- 6 years) a DDDR pacemaker was implanted for sick sinus syndrome (three cases) or second- and third-degree AV block (five cases). In five subjects chronotropic incompetence (maximal heart rate on effort < 110 beats/min) was present before implantation. One month after implantation the patients were randomized to DDDR or DDD pacing for 3 weeks each, with subsequent crossover, and at the end of each period a symptom limited cardiopulmonary exercise test (25 watts/2 min) was performed and the patients were requested to fill a symptoms questionnaire.
DDDR pacing, compared to DDD, was associated with higher maximal heart rates (127 +/- 20 vs 110 +/- 27 beats/min, P < 0.02), higher [VO2 max (25.4 +/- 6.1 vs 21.5 +/- 7.8 mL/kg/per min, P < 0.03) and higher VO2 at the anaerobic threshold (20.3 +/- 5.0 vs 15.8 +/- 4.9 mL/kg per min, P < 0.03), without significant differences in mean exercise time (526 +/- 193 vs 472 +/- 216 sec, NS). The increase in VO2 max obtained in DDDR versus DDD was significantly related to the increase in maximal heart rate (r = 0.72, P < 0.05) and the increase in VO2 at the anaerobic threshold obtained in DDDR versus DDD was related to the increase in heart rate at the anaerobic threshold (r = 0.81, P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)
8例患者（年龄62±6岁）因病态窦房结综合征（3例）或二度及三度房室传导阻滞（5例）植入DDDR起搏器。5例患者在植入前存在变时性功能不全（运动时最大心率<110次/分钟）。植入后1个月，患者被随机分为DDDR或DDD起搏组，每组3周，随后交叉，在每个阶段结束时进行症状限制性心肺运动试验（25瓦/2分钟），并要求患者填写症状问卷。
与DDD起搏相比，DDDR起搏的最大心率更高（127±20对110±27次/分钟，P<0.02），[最大摄氧量更高（25.4±6.1对21.5±7.8毫升/千克/分钟，P<0.03），无氧阈时的摄氧量更高（20.3±5.0对15.8±4.9毫升/千克/分钟，P<0.03），平均运动时间无显著差异（526±193对472±216秒，无统计学意义）。DDDR与DDD相比最大摄氧量的增加与最大心率的增加显著相关（r=0.72，P<0.05），DDDR与DDD相比无氧阈时摄氧量的增加与无氧阈时心率的增加相关（r=0.81，P<0.02）。（摘要截短至250字）
