Wasserman Karlman, Sun Xing-Guo, Hansen James E
Department of Medicine, Los Angeles Biomedical Research Institute at Harbor--UCLA Medical Center, 1124 W Carson St, Torrance, CA 90502, USA.
Chest. 2007 Jul;132(1):250-61. doi: 10.1378/chest.06-2872. Epub 2007 May 15.
Biventricular pacing (BVP) is used for cardiac resynchronization therapy in wide-QRS-complex heart failure. We sought to quantify the effect of BVP on the exercise pathophysiology of heart failure patients.
Using cardiopulmonary exercise testing, we analyzed exercise data for a multicenter study sponsored by St. Jude Medical. Patients had pacemaker electrodes implanted in both ventricles in the standard manner and were randomized by St. Jude before exercise testing. Exercise measurements included peak oxygen uptake (Vo(2)), peak O(2) pulse, anaerobic threshold (AT), and ventilatory equivalent for CO(2) (reflecting change in peak exercise cardiac output, stroke volume, maximal sustainable exercise capacity, and ventilation-perfusion mismatching, respectively) at baseline and at a 6-month follow-up. The studies included progressively and uniformly increasing work rate to maximum tolerance. The investigators were blinded both to sponsor-controlled randomization and pacemaker status. There were 239 paired 6-month studies, as follows: 47 studies served as the control with the pacemaker off (ie, the BVP-OFF group); and 192 patients received pacing (ie, the BVP-ON group).
The BVP-ON group significantly improved in all exercise parameters in contrast to the control group (p < 0.0001). When baseline measurements for the BVP-ON group were ranked in quintiles, only patients in the three functionally worst quintiles improved significantly at 6 months (peak Vo(2) < 11.6 mL/min/kg, AT < 7.6 mL/min/kg, peak O(2) pulse < 12.0 mL/beat, and minute ventilation/Vco(2) ratio at AT > 38.1) [p < 0.01 to < 0.0001].
BVP benefited aerobic function and ventilation-perfusion mismatching most in those patients with the greatest physiologic impairment.
双心室起搏（BVP）用于宽QRS波群心力衰竭的心脏再同步治疗。我们试图量化BVP对心力衰竭患者运动病理生理学的影响。
通过心肺运动试验，我们分析了圣犹达医疗公司赞助的一项多中心研究的运动数据。患者以标准方式在双心室植入起搏器电极，并在运动试验前由圣犹达公司进行随机分组。运动测量指标包括基线时和6个月随访时的峰值摄氧量（Vo₂）、峰值氧脉搏、无氧阈（AT）以及二氧化碳通气当量（分别反映运动峰值心输出量、每搏输出量、最大可持续运动能力和通气/灌注不匹配的变化）。研究包括逐渐且均匀地增加工作负荷至最大耐受程度。研究人员对赞助方控制的随机分组和起搏器状态均不知情。共有239项为期6个月的配对研究，具体如下：47项研究作为起搏器关闭的对照组（即BVP关闭组）；192例患者接受起搏治疗（即BVP开启组）。
与对照组相比，BVP开启组的所有运动参数均有显著改善（p < 0.0001）。当将BVP开启组的基线测量值按五分位数排序时，只有功能最差的三个五分位数组的患者在6个月时显著改善（峰值Vo₂ < 11.6 mL/min/kg，AT < 7.6 mL/min/kg，峰值氧脉搏 < 12.0 mL/次搏动，AT时的分钟通气量/二氧化碳排出量比值 > 38.1）[p < 0.01至 < 0.0001]。
BVP对生理功能损害最大的患者的有氧功能和通气/灌注不匹配改善最为明显。
