Centro Cardiologico Monzino, IRCCS, Milan, Italy; Dept. of Clinical Sciences and Community Health, Cardiovascular Section, University of Milano, Milano, Italy.
Cardiovascular Department, Division of Cardiology, Azienda Sanitaria Universitaria Integrata and University of Trieste, Trieste, Italy.
Int J Cardiol. 2017 Dec 1;248:252-256. doi: 10.1016/j.ijcard.2017.07.071.
A reduced cardiac output (CO) response during exercise is a major limiting factor in heart failure (HF). Oxygen consumption (VO) is directly proportional to CO. Peripheral mechanisms via arteriovenous oxygen difference (Δ(a-v)O) play a pivotal role in chronic HF. We hypothesized a weak correlation between peak VO and peak CO with a greater Δ(a-v)O variability in most severe HF.
We analyzed 278 HF patients (NYHA II-III) who performed maximal cardiopulmonary exercise test with non-invasive CO measurement by inert gas rebreathing.
Median peakVO, CO and Δ(a-v)O were 0.96 (0.78-1.28) L/min, 6.3 (5.1-8.0) L/min and 16.0 (14.2-18.0) mL/100mL respectively, with a linear relationship between VO and CO: CO=5.3×VO+1.13 (r=0.705, p<0.001). Patients were grouped according to exercise limitation. Group 1 (101 patients) peakVO<50% pred: peakVO 0.80 (0.67-0.94) L/min, peakCO 5.6 (4.7-6.5) L/min, peakΔ(a-v)O 14.8 (12.9-17.1) mL/100mL. Group 2 (89 patients) peakVO≥50-<65% pred: peakVO 1.02 (0.84-1.29) L/min, peakCO 6.4 (5.1-8.0) L/min, peakΔ(a-v)O 16.7 (15.0-18.5) mL/100mL. Group 3 (88 patients) peakVO≥65% pred: peakVO 1.28 (0.93-1.66) L/min, peakCO 8.0 (6.2-9.7) L/min, peakΔ(a-v)O 16.8 (14.6-18.3) mL/100mL. A peakVO and peakCO linear relationship was observed in Group 1 (r=0.381, p<0.001), Group 2 (r=0.756, p<0.001) and Group 3 (r=0.744, p<0.001).
With worsening HF we observed a progressive reduction of peak CO and peak VO. However in most compromised patients also peripheral mechanisms play a role as indicated by reduced Δ(a-v)O.
运动时心输出量（CO）的减少是心力衰竭（HF）的主要限制因素。耗氧量（VO）与 CO 直接成正比。通过动静脉氧差（Δ(a-v)O）的外周机制在慢性 HF 中起着关键作用。我们假设在大多数严重 HF 中，峰值 VO 与峰值 CO 之间的相关性较弱，而 Δ(a-v)O 的变异性更大。
我们分析了 278 名接受最大心肺运动试验（通过惰性气体再呼吸进行无创 CO 测量）的 HF 患者（NYHA II-III）。
中位峰值 VO、CO 和 Δ(a-v)O 分别为 0.96（0.78-1.28）L/min、6.3（5.1-8.0）L/min 和 16.0（14.2-18.0）mL/100mL，VO 与 CO 呈线性关系：CO=5.3×VO+1.13（r=0.705，p<0.001）。根据运动限制将患者分组。第 1 组（101 例）峰值 VO<50%预测值：峰值 VO 0.80（0.67-0.94）L/min，峰值 CO 5.6（4.7-6.5）L/min，峰值 Δ(a-v)O 14.8（12.9-17.1）mL/100mL。第 2 组（89 例）峰值 VO≥50-<65%预测值：峰值 VO 1.02（0.84-1.29）L/min，峰值 CO 6.4（5.1-8.0）L/min，峰值 Δ(a-v)O 16.7（15.0-18.5）mL/100mL。第 3 组（88 例）峰值 VO≥65%预测值：峰值 VO 1.28（0.93-1.66）L/min，峰值 CO 8.0（6.2-9.7）L/min，峰值 Δ(a-v)O 16.8（14.6-18.3）mL/100mL。第 1 组（r=0.381，p<0.001）、第 2 组（r=0.756，p<0.001）和第 3 组（r=0.744，p<0.001）均观察到峰值 VO 和峰值 CO 的线性关系。
随着 HF 的恶化，我们观察到峰值 CO 和峰值 VO 逐渐降低。然而，在大多数病情严重的患者中，外周机制也发挥了作用，这表明 Δ(a-v)O 降低。
