title: Cardiopulmonary exercise testing in healthy children and adolescents at moderately high altitude.
abstract: OBJECTIVE
  Cardiopulmonary exercise testing is a tool that helps clinicians to establish diagnosis and calculate risk stratification in adults. However, the utility of this test among children with congenital heart disease has not been fully explored. The goal of this study was to describe reference values for cardiopulmonary performance of healthy children.
  
  
  METHODS
  This study included 103 apparently healthy children (aged from 4 to 18 years; 61 boys), who underwent cardiopulmonary test using a treadmill protocol. All tests took place at 2240m above sea level (Mexico City).
  
  
  RESULTS
  Exercise time was 11±4min. There were no complications. Peak oxygen uptake correlated closely with height in both genders (girls r=0.84; boys r=0.84, p<0.001). A multivariable linear regression model showed that body surface area, exercise time, gender and heart rate reserve were significant predictors of peak oxygen uptake (R(2)=0.815, p<0.001). Peak oxygen uptake was strongly associated with age even among children younger than thirteen years (r=0.74, p<0.001).
  
  
  CONCLUSIONS
  This study provides physiological values for the major cardiopulmonary variables obtained from exercise testing using a treadmill among healthy children. Cardiopulmonary exercise test can be safely and effectively performed in young children even as young as 4 years old. Variables including age, gender and height are strongly associated with exercise time, peak heart rate and peak oxygen uptake. Regression equations for predicting peak heart rate and peak oxygen uptake are presented as reference values that allow researchers to compare children with heart disease versus those who are healthy.
authors.affiliation: Servicio de Rehabilitación Cardiaca, Instituto Nacional de Cardiología Ignacio Chávez, México, DF, México. Electronic address: hermes_ilarraza@yahoo.com.
authors.forename: Hermes
authors.initials: H
authors.lastname: Ilarraza-Lomelí
authors.forename: Javier
authors.initials: J
authors.lastname: Castañeda-López
authors.forename: Jonathan
authors.initials: J
authors.lastname: Myers
authors.forename: Irma
authors.initials: I
authors.lastname: Miranda
authors.forename: Paula
authors.initials: P
authors.lastname: Quiroga
authors.forename: María-Dolores
authors.initials: MD
authors.lastname: Rius
authors.forename: César
authors.initials: C
authors.lastname: Lopez-de-la-Vega
authors.forename: Enrique
authors.initials: E
authors.lastname: Vallejo
authors.forename: Juan
authors.initials: J
authors.lastname: Calderón
authors.forename: Javier
authors.initials: J
authors.lastname: Figueroa
authors.forename: Alfonso
authors.initials: A
authors.lastname: Buendía
mesh_terms: D000293:Adolescent; D000531:Altitude; D002648:Child; D002675:Child, Preschool; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D012016:Reference Values
keywords: Cardiopatía congénita; Cardiopulmonary exercise testing; Children; Congenital heart disease; Consumo de oxígeno; México; Niños; Oxygen uptake; Prueba de ejercicio cardiopulmonar