Feasibility of a Novel Method for Mobile Open Field Stress Testing in Young Children

Objectives: Evaluation of peak oxygen uptake (VO2peak) plays an important role in the diagnosis of congestive heart failure in congenital heart disease (CHD) patients. Although well established in older children and adults, treadmill or bicycle stress testing is of limited value in young children due to anatomical limitations. The current study evaluated the feasibility of a novel method for mobile open field stress testing in young children.

Methods: A group of children aged 4 to 8 years without history of heart disease and a group of children with history of either surgery for the tetralogy of Fallot, transposition of the great arteries, or the Fontan-like palliation will be included. NYHA scoring, clinical examination, ECG and echocardiography will be performed in all children. In children with CHD, venous NT-proBNP levels will be determined. A mobile spiroergometry device will be used, consisting of a mask attached to a breath-by-breath analyzator device which will be worn by children as a light backpack. Simultaneous recording of three-channel ECG will be performed. Live ergometry and ECG data will be sent via Bluetooth LE to a laptop with analysis software. Vital signs are monitored by a physician present at ergometry. All children perform ergometry outdoors during running on a track for 8 minutes. Running speed will be increased every 2 minutes. At 6 minutes, children will be asked to run at maximum speed until exhaustion is achieved.

Result: Currently, 65 children were included into the study. In six (9.2%) children, mobile spiroergometry was not feasible due to failure of monitoring equipment. In one (1.5%) child, maximal exhaustion (defined as RER ≤0.95 at VO2peak) was not achieved. The remaining 46 children without CHD achieved a VO2peak of 52.83 ± 4.86 mL/(kg × min). The remaining 12 children with CHD achieved a VO2peak of 38.75 ± 5.22 mL/(kg × min). VO2peak differed significantly (p < 0.01) between the groups.

Conclusion: Mobile open field stress testing seems to be feasible in children aged 4 to 8 years. Significant VO2peak differences in healthy children compared with children with CHD were observed. Further research regarding the diagnostic performance of mobile stress testing is needed.

Publication History

Article published online:
21 February 2021