Moderators of peak respiratory exchange ratio during exercise testing in children and adolescents with Fontan physiology.

Creator(s)

Patricia M. Carey
Hung-Wen Yeh, Children's Mercy HospitalFollow
Karoline Krzywda, Children's Mercy HospitalFollow
Kelli M. Teson, Children's Mercy HospitalFollow
Jessica S. Watson, Children's Mercy HospitalFollow
Suma Goudar
Daniel Forsha, Children's Mercy HospitalFollow
David A. White, Children's Mercy Hospitals and ClinicsFollow

Document Type

Article

Publication Date

11-2023

Identifier

DOI: 10.1017/S1047951123000227

Abstract

OBJECTIVES: Many patients with Fontan physiology are unable to achieve the minimum criteria for peak effort during cardiopulmonary exercise testing. The purpose of this study is to determine the influence of physical activity and other clinical predictors related to achieving peak exercise criteria, signified by respiratory exchange ratio ≥ 1.1 in youth with Fontan physiology.

METHODS: Secondary analysis of a cross-sectional study of 8-18-year-olds with single ventricle post-Fontan palliation who underwent cardiopulmonary exercise testing (James cycle protocol) and completed a past-year physical activity survey. Bivariate associations were assessed by Wilcoxon rank-sum test and simple regression. Conditional inference forest algorithm was used to classify participants achieving respiratory exchange ratio > 1.1 and to predict peak respiratory exchange ratio.

RESULTS: Of the n = 43 participants, 65% were male, mean age was 14.0 ± 2.4 years, and 67.4% (n = 29) achieved respiratory exchange ratio ≥ 1.1. Despite some cardiopulmonary exercise stress test variables achieving statistical significance in bivariate associations with participants achieving respiratory exchange ratio > 1.1, the classification accuracy had area under the precision recall curve of 0.55. All variables together explained 21.4% of the variance in respiratory exchange ratio, with peak oxygen pulse being the most informative.

CONCLUSION: Demographic, physical activity, and cardiopulmonary exercise test measures could not classify meeting peak exercise criteria (respiratory exchange ratio ≥ 1.1) at a satisfactory accuracy. Correlations between respiratory exchange ratio and oxygen pulse suggest the augmentation of stroke volume with exercise may affect the Fontan patient's ability to sustain high-intensity exercise.

Journal Title

Cardiology in the young

Volume

33

Issue

11

First Page

2334

Last Page

2341

MeSH Keywords

Humans; Male; Adolescent; Child; Female; Exercise Test; Cross-Sectional Studies; Exercise Tolerance; Respiratory Function Tests; Fontan Procedure; Oxygen Consumption; Oxygen; Heart Defects, Congenital

Keywords

CHD; Fontan palliation; exercise stress test; respiratory exchange ratio

Comments

Grants and funding

• K23 HL159325/HL/NHLBI NIH HHS/United States

Recommended Citation

Carey PM, Yeh HW, Krzywda K, et al. Moderators of peak respiratory exchange ratio during exercise testing in children and adolescents with Fontan physiology. Cardiol Young. 2023;33(11):2334-2341. doi:10.1017/S1047951123000227