Epperlein S, Treese N, Stegmaier A, Coutinho M, Meyer J
II. Medizinische Klinik und Poliklinik, Johannes-Gutenberg-Universität, Mainz.
Z Kardiol. 1994 May;83(5):343-50.
This study was designed to assess the effect of acute minute ventilation sensing, rate-responsive pacing on cardiopulmonary exercise capacity in 27 patients (mean age 60 years) with chronotropic incompetence. The exercise protocol consisted of bicycle exercise in semisupine position with breath-to-breath analysis of gas exchange. At the anaerobic threshold heart rate increased from 75 +/- 9 in the VVI-mode to 113 +/- 21 beats/min in the VVI-R-mode (p < 0.001), oxygen uptake from 9.3 +/- 3.4 to 10.9 +/- 4.3 ml/kg/min (p < 0.001) and work rate from 52 +/- 20 to 65 +/- 24 watts (p < 0.001). Compared to 41 normal subjects, VVI-R pacing increased oxygen uptake up to 75% and work rate up to 79% of normal values, while heart rate increased similarly in both groups. The VO2 to work rate ratio (dVO2/dWR), calculated as the slope of the relation of oxygen uptake to work rate below the anaerobic threshold, improved from 7.9 +/- 2.3 to 10.2 +/- 2.4 ml/min/watts (p < 0.001) in the VVI-R-mode; so it did not differ from normal values. Thus, acute respiratory dependent rate-responsive pacing results in substantial improvement in cardiopulmonary exercise capacity in patients with chronotropic incompetence. The VO2 to work rate ratio demonstrated to be a reliable parameter for assessing this improvement.
本研究旨在评估27例（平均年龄60岁）变时性功能不全患者中急性分钟通气量感知、频率应答性起搏对心肺运动能力的影响。运动方案包括半卧位自行车运动，并对气体交换进行逐次呼吸分析。在无氧阈时，心率从VVI模式下的75±9次/分钟增加到VVI-R模式下的113±21次/分钟（p<0.001），摄氧量从9.3±3.4增加到10.9±4.3毫升/千克/分钟（p<0.001），工作负荷从52±20瓦增加到65±24瓦（p<0.001）。与41名正常受试者相比，VVI-R起搏使摄氧量增加至正常值的75%，工作负荷增加至正常值的79%，而两组心率的增加情况相似。在VVI-R模式下，无氧阈以下摄氧量与工作负荷关系的斜率计算得出的VO2与工作负荷比值（dVO2/dWR）从7.9±2.3提高到10.2±2.4毫升/分钟/瓦（p<0.001）；因此与正常值无差异。因此，急性呼吸依赖性频率应答性起搏可使变时性功能不全患者的心肺运动能力得到显著改善。VO2与工作负荷比值被证明是评估这种改善的可靠参数。
