Cardiovascular Intensive Care, Saint-Luc University Hospital, Brussels, Belgium.
Artif Organs. 2011 Jul;35(7):682-90. doi: 10.1111/j.1525-1594.2011.01227.x. Epub 2011 May 25.
Exercise capacity is improved in patients supported with continuous flow rotary blood pumps (RP). The aim of this study was to investigate the mechanisms underlying this improvement. Ten patients implanted with a RP underwent cardiopulmonary exercise testing (CPET) at 6 months after surgery with hemodynamic and metabolic measurements (RP group). A group of 10 matched heart failure patients were extracted from our heart transplant database, and the results of their last CPET before transplantation were used for comparison (heart failure [HF] group). Peak VO(2) was significantly higher in RP than in HF patients (15.8 ± 6.2 vs. 10.9 ± 3 mL O(2)/kg.min) reaching 52 ± 16% of their predicted peak VO(2). The total output measured by a Swan-Ganz catheter increased from 5.6 ± 1.6 to 9.2 ± 1.8 L/min in the RP group and was significantly higher at rest and at peak exercise than in the HF group, whose output increased from 3.5 ± 0.4 to 5.6 ± 1.6 L/min. In the RP group, the estimated pump flow increased from 5.3 ± 0.4 to 6.2 ± 0.8, whereas the native cardiac output increased from 0.0 ± 0.5 to 3 ± 1.7 L/min. Cardiac output at peak exercise was inversely correlated with age (r = -0.86, P = 0.001) and mean pulmonary artery pressure (r = -0.75, P = 0.012). Maximal exercise capacity is improved in patients supported by RP as compared to matched HF patients and reaches about 50% of the expected values. Both a spontaneous increase of pump flow at constant pump speed and an increase of the native cardiac output contribute to total flow elevation. These findings may suggest that an automatic pump speed adaptation during exercise would further improve the exercise capacity. This hypothesis should be examined.
使用连续流动旋转血泵（RP）支持的患者的运动能力得到改善。本研究的目的是研究这种改善的机制。 10 名接受 RP 手术的患者在手术后 6 个月接受心肺运动测试（CPET），并进行血流动力学和代谢测量（RP 组）。从我们的心脏移植数据库中提取了一组 10 名匹配的心力衰竭患者，并使用他们移植前最后一次 CPET 的结果进行比较（心力衰竭[HF]组）。 RP 组的峰值 VO（2）显著高于 HF 组（15.8 ± 6.2 比 10.9 ± 3 mL O（2）/kg.min），达到其预测峰值 VO（2）的 52 ± 16％。通过 Swan-Ganz 导管测量的总输出从 RP 组的 5.6 ± 1.6 增加到 9.2 ± 1.8 L/min，在休息和峰值运动时均明显高于 HF 组，其输出从 3.5 ± 0.4 增加到 5.6 ± 1.6 L/min。在 RP 组中，估计的泵流量从 5.3 ± 0.4 增加到 6.2 ± 0.8，而原生心输出量从 0.0 ± 0.5 增加到 3 ± 1.7 L/min。峰值运动时的心输出量与年龄（r = -0.86，P = 0.001）和平均肺动脉压（r = -0.75，P = 0.012）呈负相关。与匹配的 HF 患者相比，使用 RP 支持的患者的最大运动能力得到改善，达到预期值的 50％左右。恒定泵速下泵流量的自发增加和原生心输出量的增加均有助于总流量升高。这些发现可能表明，在运动过程中自动调节泵速将进一步改善运动能力。应该检验这个假设。
