Context: There is evidence that OSA in children can be associated with acute and chronic effects on the cardiovascular system due to repetitive episodes of apnea and hypoxemia.Objective: To assess whether there is an association between OSA and echocardiographic findings in children and whether that association persists after adenotonsillectomy.Data sources: A literature search was conducted based on PUBMED, EMBASE and LILACS.Study selection: Children with USA and children who did not have USA, who were aged <= 12 years.Data extraction: Two reviewers extracted data independently; the risk of bias was assessed by examining the selected sample, the recruitment method, completeness of follow up, and blinding.Results: Seven studies met all the inclusion criteria and methodological requirements. There was a significant difference with elevated mean pulmonary arterial pressure levels in OSA participants compared to those without OSA at preoperative assessment [mean difference (MD) 8.67; confidential interval (CI) 95% 6.09, 11.25]. OSA participants showed a statistically significant increased interventricular septum (IVS) thickness (mm) [MD 0.60; CI 95% 0.09, 1.11]; and right ventricular (RV) dimension (cm/m) [MD 0.19; CI 95% 0.10, 0.28]. There was also a significant increase in right ventricular (RV) dimension (cm/m) [MD 0.10; Cl 95% 0.05, 0.14] in OSA children.Conclusion: There is moderate quality evidence regarding possible association between USA and right heart repercussions. More prognosis studies are needed, to allow the combination of results in a meta-analysis. (C) 2014 Elsevier Ireland Ltd. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)