Blood Pressure Response to Treadmill Cardiopulmonary Exercise Test in Children with Normal Cardiac Anatomy and Function

Objectives: To describe blood pressure (BP) responses during cardiopulmonary exercise testing (CPET) and propose criteria for abnormal BP responses in children with normal hearts. Study design: Treadmill CPET data of children <18 years with normal hearts were retrospectively analyzed to evaluate BP responses to exercise at the Children's Hospital of Michigan over an 8-year period (2011-2018). Results: Our cohort included 1085 children (boys, 59%) aged 7-17 years. Analysis of variance for systolic BP at peak exercise (peak SBP) and SBP change (Δ) showed significant age and sex effects and age–sex interaction effects (P <.01). In the multiple linear regression model (P <.001, R square 0.298, standard error of the estimate 17.15), peak SBP (mm Hg) was predicted as 132.27 + 1.37 × age (years) + (3.31 × age (years) – 31.88) × sex [boys 1, girls 0]. The following criteria for abnormal BP responses in children were proposed: hypertensive BP response was defined by peak SBP with a 90% CI upper limit of reference values based on age and sex, and blunted BP response as ΔSBP <10 mm Hg for aged 7-11 years, <20 mm Hg for boys aged 12–17 years, and ΔSBP <10 mm Hg in girls. Conclusions: BP responses to treadmill CPET depend on age and sex in children with normal hearts. The proposed criteria for abnormal BP responses in children during CPET will need to be verified in a large pediatric cohort.