Related Experiment Video
Updated: Dec 31, 2025
How to Administer Near-Infrared Spectroscopy in Critically ill Neonates, Infants, and Children
Published on: August 19, 2020
Different Patterns of Cerebral and Muscular Tissue Oxygenation 10 Years After Coarctation Repair
Kristof Vandekerckhove1, Joseph Panzer1, Ilse Coomans1
1Department of Pediatric Cardiology, Ghent University Hospital, Ghent, Belgium.
Insights
Children after coarctation repair show altered oxygenation in muscles and brain during exercise, contributing to reduced exercise tolerance. This study investigated peripheral tissue oxygenation changes in these children compared to healthy controls.
Area of Science:
- Cardiology
- Pediatric Exercise Physiology
- Biomedical Engineering
Background:
- Coarctation of the aorta is a congenital heart defect requiring surgical repair.
- Children post-coarctation repair often exhibit reduced exercise tolerance.
- Peripheral tissue oxygenation during exercise is a potential factor influencing exercise capacity.
Purpose of the Study:
- To determine if impaired exercise tolerance in children after coarctation repair is linked to altered peripheral tissue oxygenation during physical exertion.
- To compare cerebral and locomotor muscle oxygenation responses between children post-coarctation repair and healthy controls.
Main Methods:
- Near-infrared spectroscopy (NIRS) was used to measure cerebral and muscle oxygenation in 16 children post-coarctation repair and 20 healthy controls during incremental ramp exercise tests.
- Key metrics included tissue oxygenation index (TOI), oxygenated hemoglobin (O2Hb), and deoxygenated hemoglobin (HHb).
- Correlations were examined between residual blood pressure gradients and local oxygenation responses.
Main Results:
- Children post-coarctation repair demonstrated significantly lower peak power output and peak oxygen consumption compared to controls.
- Cerebral oxygenation showed reduced increases in O2Hb and HHb in patients during exercise.
- Muscle oxygenation revealed lower TOI and higher HHb in patients, with no difference in muscle O2Hb.
- A significant correlation was found between resting blood pressure gradient and muscle HHb changes.
Conclusions:
- Children following coarctation repair exhibit distinct cerebral and muscular oxygenation patterns during exercise.
- These altered oxygenation responses suggest an imbalance between oxygen supply and demand.
- This physiological difference may contribute to the diminished exercise tolerance observed in this population.
Abstract:
The purpose of this study was to assess whether the lower exercise tolerance in children after coarctation repair is associated with alterations in peripheral tissue oxygenation during exercise. A total of 16 children after coarctation repair and 20 healthy control subjects performed an incremental ramp exercise test to exhaustion. Cerebral and locomotor muscle oxygenation were measured by means of near infrared spectroscopy. The responses of cerebral and muscle tissue oxygenation index (cTOI, mTOI), oxygenated (O2Hb), and deoxygenated hemoglobin (HHb) as a function of work rate were compared. Correlations between residual continuous wave Doppler gradients at rest, arm-leg blood pressure difference and local oxygenation responses were evaluated. Age, length, and weight was similar in both groups. Patients with aortic coarctation had lower peak power output (Ppeak) (72.3 ± 20.2% vs. 106 ± 18.7%, P < 0.001), VO2peak/kg (37.3 ± 9.1 vs. 44.2 ± 7.6 ml/kg, P = 0.019) and %VO2peak/kg (85.7 ± 21.9% vs. 112.1 ± 15.5%, P < 0.001). Cerebral O2Hb and HHb had a lower increase in patients vs. controls during exercise, with significant differences from 60 to 90% Ppeak (O2Hb) and 70% to 100% Ppeak (HHb). Muscle TOI was significantly lower in patients from 10 to 70% Ppeak and muscle HHb was significantly higher in patients vs. controls from 20 to 80% Ppeak. Muscle O2Hb was not different between both groups. There was a significant correlation between residual resting blood pressure gradient and Δmuscle HHb/ΔP at 10-20W and 20-30W (r = 0.40, P = 0.039 and r = 0.43, P = 0.034). Children after coarctation repair have different oxygenation responses at muscular and cerebral level. This reflects a different balance between O2 supply to O2 demand which might contribute to the reduced exercise tolerance in this patient population.
