Vignati Carlo, Apostolo Anna, Cattadori Gaia, Farina Stefania, Del Torto Alberico, Scuri Silvia, Gerosa Gino, Bottio Tomaso, Tarzia Vincenzo, Bejko Jonida, Sisillo Erminio, Nicoli Flavia, Sciomer Susanna, Alamanni Francesco, Paolillo Stefania, Agostoni Piergiuseppe
Centro Cardiologico Monzino, IRCCS, Milan, Italy.
Centro Cardiologico Monzino, IRCCS, Milan, Italy; Multimedica, IRCCS, Milano, Italy.
Int J Cardiol. 2017 Mar 1;230:28-32. doi: 10.1016/j.ijcard.2016.12.112. Epub 2016 Dec 22.
Peak exercise cardiac output (CO) increase is associated with an increase of peak oxygen uptake (VO), provided that arteriovenous O difference [Δ(Ca-Cv)O] does not decrease. At anaerobic threshold, VO, is related to CO. We tested the hypothesis that, in heart failure (HF) patients with left ventricular assistance device (LVAD), an acute increase of CO obtained through changes in LVAD pump speed is associated with peak exercise and anaerobic threshold VO increase.
Fifteen of 20 patients bearing LVAD (Jarvik 2000) enrolled in the study successfully performed peak exercise evaluation. All patients had severe HF as shown by clinical evaluation, laboratory tests, echocardiography, spirometry with alveolar-capillary diffusion, and maximal cardiopulmonary exercise testing (CPET). CPETs with non-invasive CO measurements at rest and peak exercise were done on 2days at LVAD pump speed set randomly at 2 and 4.
Increasing LVAD pump speed from 2 to 4 increased CO from 3.4±0.9 to 3.8±1.0L/min (ΔCO 0.4±0.6L/min, p=0.04) and from 5.3±1.3 to 5.9±1.4L/min (ΔCO 0.6±0.7L/min, p<0.01) at rest and peak exercise, respectively. Similarly, VO increased from 788±169 to 841±152mL/min (ΔVO 52±76mL/min, p=0.01) and from 568±116 to 619±124mL/min (ΔVO 69±96mL/min, p=0.02) at peak exercise and at anaerobic threshold, respectively. Δ(Ca-Cv)O did not change significantly, while ventilatory efficiency improved (VE/VCO slope from 39.9±5.4 to 34.9±8.3, ΔVE/VCO -5.0±6.4, p<0.01).
In HF, an increase in CO with a higher LVAD pump speed is associated with increased peak VO, postponed anaerobic threshold, and improved ventilatory efficiency.
如果动静脉氧分压差[Δ（Ca - Cv）O]不降低，运动峰值心输出量（CO）的增加与峰值摄氧量（VO）的增加相关。在无氧阈时，VO与CO相关。我们检验了这样一个假设，即在使用左心室辅助装置（LVAD）的心力衰竭（HF）患者中，通过改变LVAD泵速使CO急性增加与运动峰值和无氧阈时VO的增加相关。
20例使用LVAD（Jarvik 2000）的患者中有15例成功入选本研究并完成了运动峰值评估。所有患者经临床评估、实验室检查、超声心动图、肺泡 - 毛细血管弥散肺量计及最大心肺运动试验（CPET）证实均患有严重心力衰竭。在LVAD泵速随机设定为2和4的两天内，进行了静息和运动峰值时无创CO测量的CPET。
将LVAD泵速从2提高到4时，静息和运动峰值时的CO分别从3.4±0.9升至3.8±1.0L/分钟（ΔCO 0.4±0.6L/分钟，p = 0.04）和从5.3±1.3升至5.9±1.4L/分钟（ΔCO 0.6±0.7L/分钟，p<0.01）。同样，运动峰值和无氧阈时的VO分别从788±169升至841±152mL/分钟（ΔVO 52±76mL/分钟，p = 0.01）和从568±116升至619±124mL/分钟（ΔVO 69±96mL/分钟，p = 0.02）。Δ（Ca - Cv）O无显著变化，而通气效率提高（VE/VCO斜率从39.9±5.4降至34.9±8.3，ΔVE/VCO -5.0±6.4，p<0.01）。
在心力衰竭患者中，提高LVAD泵速使CO增加与运动峰值VO增加、无氧阈延迟及通气效率提高相关。
