Segel Michael J, Bobrovsky Ben-Zion, Gabbay Itay E, Ben-Dov Issahar, Reuveny Ronen, Gabbay Uri
Lung Institute, Sheba Medical Center, Ramat-Gan, Israel; Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
School of Electrical Engineering-Systems, Faculty of Engineering, Tel-Aviv University, Tel-Aviv, Israel.
Int J Cardiol. 2017 May 1;234:33-37. doi: 10.1016/j.ijcard.2017.02.081. Epub 2017 Feb 24.
The Cardio-vascular reserve index (CVRI) had been empirically validated in diverse morbidities as a quantitative estimate of the reserve assumed by the cardiovascular reserve hypothesis. This work evaluates whether CVRI during exercise complies with the cardiovascular reserve hypothesis.
Retrospective study based on a database of patients who underwent cardio-pulmonary exercise testing (CPX) for diverse indications.
Patient's physiological measurements were retrieved at four predefined CPX stages (rest, anaerobic threshold, peak exercise and after 2min of recovery). CVRI was individually calculated retrospectively at each stage.
Mean CVRI at rest was 0.81, significantly higher (p<0.001) than at all other stages. CVRI decreased with exercise, reaching an average at peak exercise of 0.35, significant lower than at other stages (p<0.001) and very similar regardless of exercise capacity (mean CVRI 0.33-0.37 in 4 groups classified by exercise capacity, p>0.05). CVRI after 2min of recovery rose considerably, most in the group with the best exercise capacity and least in those with the lowest exercise capacity.
CVRI during exercise fits the pattern predicted by the cardiovascular reserve hypothesis. CVRI decreased with exercise reaching a minimum at peak exercise and rising with recovery. The CVRI nadir at peak exercise, similar across groups classified by exercise capacity, complies with the assumed exhaustion threshold. The clinical utility of CVRI should be further evaluated.
心血管储备指数（CVRI）已在多种疾病中得到经验验证，可作为心血管储备假说所假定储备的定量估计。本研究评估运动期间的CVRI是否符合心血管储备假说。
基于因各种适应症接受心肺运动试验（CPX）的患者数据库进行的回顾性研究。
在四个预定义的CPX阶段（休息、无氧阈值、运动峰值和恢复2分钟后）获取患者的生理测量值。在每个阶段回顾性地单独计算CVRI。
静息时的平均CVRI为0.81，显著高于所有其他阶段（p<0.001）。CVRI随运动而降低，在运动峰值时平均达到0.35，显著低于其他阶段（p<0.001），并且无论运动能力如何都非常相似（按运动能力分类的4组中平均CVRI为0.33 - 0.37，p>0.05）。恢复2分钟后的CVRI大幅上升，在运动能力最佳的组中上升最多，在运动能力最低的组中上升最少。
运动期间的CVRI符合心血管储备假说所预测的模式。CVRI随运动降低，在运动峰值时达到最低，随恢复而上升。运动峰值时的CVRI最低点在按运动能力分类的各组中相似，符合假定的耗竭阈值。CVRI的临床效用应进一步评估。
