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)Univ Estadual Paulista, UNESP, Botucatu Med Sch, Dept Anaesthesiol,Evidence Based Med Unit, Sao Paulo, SP, BrazilUniv Estadual Paulista, UNESP, Botucatu Med Sch, Botucatu, SP, BrazilSydney Childrens Hosp Network, Cochrane Prognosis Grp, Sydney, NSW, AustraliaUniv Melbourne, Cochrane Prognosis Grp, Parkville, Vic 3052, AustraliaRoyal Childrens Hosp Melbourne, Parkville, Vic, AustraliaMurdoch Childrens Res Inst, Parkville, Vic, AustraliaMcMaster Univ, McMaster Inst Urol, Hamilton, ON, CanadaUniv Estadual Paulista, UNESP, Botucatu Med Sch, Dept Anaesthesiol,Evidence Based Med Unit, Sao Paulo, SP, BrazilUniv Estadual Paulista, UNESP, Botucatu Med Sch, Botucatu, SP, BrazilFAPESP: 11/18762-9