Introduction Cardio-pulmonary exercise test (CPET) is becoming a key examination to assess physical capacity and disease severity in paediatric cardiology. The VE/VCO₂ slope has been increasingly used as a surrogate marker for morbidity and mortality in adult heart failure, pulmonary arterial hypertension and for adult patients with CHD. Nevertheless, the use of the VE/VCO₂ slope in children remains limited in the absence of reference values and clearly identified clinical determinants. This study aimed to compare the VE/VCO₂ slope in a paediatric cohort with CHD to that of age- and gender-adjustedhealthy controls. We also intended to identify the clinical and CPET variables associated with VE/VCO₂ slope in this population. Methods This cross-sectional study was carried out between November 2010 and September 2015 in two tertiary care paediatric cardiology reference centres. Results A total of 700 children were enrolled (399 CHD and 301 healthy controls). The mean VE/VCO₂ slope was significantly higher in CHD than in healthy subjects (31.6±4.8 vs. 29.3±4.8; P<0.001). The VE/VCO₂ slope was higher in children with significant pulmonary regurgitation, tricuspid regurgitation, right ventricular hypertension and right ventricle outflow tract (RVOT) obstacle. In the CHD group, VE/VCO₂ slope increase was associated with BMI, the presence of a RVOT obstacle, the number of cardiac catheter procedures, as well as low age, FVC, tidal volume, and PetCO2. Conclusion Increased VE/VCO₂ slope was predominantly in children with single ventricle and/or residual right heart abnormalities suggesting that maldistribution of pulmonary blood flow during exercise is an important CHD-unique determinant of VE/VCO₂ slope.

中文翻译：

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VE / VCO2斜率：评估先天性心脏病儿童生理状况的有用工具。

引言心肺运动测试（CPET）成为评估儿科心脏病学中身体能力和疾病严重程度的一项关键检查。VE / VCO ₂斜率已越来越多地用作成人心力衰竭，肺动脉高压和成人CHD患者发病率和死亡率的替代指标。然而，在没有参考值和明确确定的临床决定因素的情况下，儿童使用VE / VCO ₂斜率仍然受到限制。这项研究旨在比较有冠心病的小儿队列的VE / VCO ₂斜率与按年龄和性别调整的健康对照者的斜率进行比较。我们还打算确定与VE / VCO ₂相关的临床和CPET变量此人口的坡度。方法这项横断面研究是在2010年11月至2015年9月期间在两个三级医疗儿科心脏病参考中心进行的。结果总共招募了700名儿童（399名CHD和301名健康对照）。冠心病患者的平均VE / VCO ₂斜率显着高于健康受试者（31.6±4.8对29.3±4.8； P <0.001）。患有严重肺反流，三尖瓣反流，右心室高血压和右心室流出道（RVOT）障碍的儿童的VE / VCO ₂斜率更高。在CHD组中，VE / VCO ₂坡度增加与BMI，RVOT障碍物的存在，心脏导管手术的次数以及低龄，FVC，潮气量和PetCO2相关。结论VE / VCO ₂斜率升高主要发生在单心室和/或残留右心异常的患儿中，这表明运动期间肺血流分布不均是VED / VCO ₂斜率的一个重要的CHD决定因素。