Children with Burn Injury Have Impaired Cardiac Output during Submaximal Exercise.
Med Sci Sports Exerc
; 49(10): 1993-2000, 2017 Oct.
Article
em En
| MEDLINE
| ID: mdl-28538026
ABSTRACT
INTRODUCTION:
Burn trauma damages resting cardiac function; however, it is currently unknown if the cardiovascular response to exercise is likewise impaired. We tested the hypothesis that, in children, burn injury lowers cardiac output (QË) and stroke volume (SV) during submaximal exercise.METHODS:
Five children with 49% ± 4% total body surface area (BSA) burned (two female, 11.7 ± 1 yr, 40.4 ± 18 kg, 141.1 ± 9 cm) and eight similar nonburned controls (five female, 12.5 ± 2 yr, 58.0 ± 17 kg, 147.3 ± 12 cm) with comparable exercise capacity (peak oxygen consumption [peak VËO2] 31.9 ± 11 vs 36.8 ± 8 mL O2·kg·min, P = 0.39) participated. The exercise protocol entailed a preexercise (pre-EX) rest period followed by 3-min exercise stages at 20 W and 50 W. VËO2, HR, QË (via nonrebreathing), SV (QË/HR), and arteriovenous O2 difference ([a-v]O2diff, QË/ VËO2) were the primary outcome variables.RESULTS:
Using a 2-way factorial ANOVA (group [G] × exercise [EX]), we found that QË was approximately 27% lower in the burned than the nonburned group at 20 W of exercise (burned 5.7 ± 1.0 vs nonburned 7.9 ± 1.8 L·min) and 50 W of exercise (burned 6.9 ± 1.6 vs nonburned 9.2 ± 3.2 L·min) (G-EX interaction, P = 0.012). SV did not change from rest to exercise in burned children but increased by approximately 24% in the nonburned group (main effect for EX, P = 0.046). Neither [a-v] O2diff nor VËO2 differed between groups at rest or exercise, but HR response to exercise was reduced in the burn group (G-EX interaction, P = 0.004). When normalized to BSA, SV (index) was similar between groups; however, QË (index) remained attenuated in the burned group (G-EX interaction, P < 0.008).CONCLUSIONS:
Burned children have an attenuated cardiovascular response to submaximal exercise. Further investigation of hemodynamic function during exercise will provide insights important for cardiovascular rehabilitation in burned children.
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Base de dados:
MEDLINE
Assunto principal:
Queimaduras
/
Débito Cardíaco
/
Exercício Físico
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article