Schoffl I; Department of Pediatric Cardiology, Erlangen,Germany.
Trager E; Kessler L; Paech C;et al

Pediatric Exercise Science. 38(3):315-323, 2026 Aug 01.

PURPOSES: In pediatric cardiology, stress echocardiography is rarely used,
even though it is an established tool for investigating myocardial
dysfunction due to coronary insufficiency, a threat in children after
arterial switch operation (ASO) or Kawasaki disease (KD). This study
combines stress echocardiography with cardiopulmonary exercise testing in
this cohort.

METHOD: The participants in this study were recruited from a cohort of
patients after ASO or KD. An age- and sex-matched control group was
recruited from university students and school children from nearby
schools. All undertook a cardiopulmonary exercise testing either on a
tilt-recline cycle ergometer or on a treadmill with intermittent
echocardiography. The echocardiographic examination consisted of global
longitudinal strain measurements of the left ventricle as parameters of
left ventricular function. In addition to the standard cardiopulmonary
exercise parameters (peak oxygen consumption, peak heart rate, O2pulse,
oxygen uptake efficiency slope, VE/VCO2-slope, and others), the behavior
of the O2pulse before and after the end of exercise was evaluated.

RESULTS: Overall, 43 participants were recruited (20 ASO, mean age: 14.7
y, 8 females; 10 KD, mean age: 15.0 y, 3 females; 13 controls, mean age:
15.7 y, 5 females). The patients after ASO showed a significantly lower
peak cardiopulmonary function (VO2peak: 39.6 vs 45.9 mL/kg/min) than the
control group. When combined (KD and ASO patients), the first ventilatory
threshold as well as the decline of the O2pulse during recovery were
significantly lower than in the control group. There were no differences
with respect to the echocardiographic parameters.

CONCLUSION: The lower peak oxygen consumption observed in the ASO group
point to a lower cardiopulmonary function. The lower oxygen consumption at
first ventilatory threshold can be an indicator of poorer endurance. Even
though the ventricular function recorded using echocardiography showed no
significant decrease, the slower recovery of the O2pulse during recovery
could point to an impairment in cardiac output during exercise as the
O2pulse is a surrogate parameter of cardiac output at peak exercise