Cardiac systolic function in Greek children with obstructive sleep-disordered breathing

Abstract

Background: Obstructive sleep-disordered breathing (SOB) in children has been associated with increased ventricular strain and decreased left ventricle (LV) diastolic function. The aim of this study was to assess systolic myocardial function in children with SDB of variable severity. Methods: Children who were referred for polysomnography during the study period underwent echocardiography (two-dimensional, Doppler and tissue Doppler imaging). Results: A total of 46 subjects (age 6.4 +/- 2.6 years) were recruited. Fourteen of them had moderate-to-severe SDB (obstructive apnea-hypopnea index (OAHI): 16.6 +/- 11.6 episodes/h), 13 children had mild SDB (OAHI: 3.1 +/- 0.7 episodes/h) and 19 subjects had primary snoring (OAHI: 1.2 +/- 0.6 episodes/h). Children with moderate-to-severe SOB had significantly lower LV shortening fraction (SF) and ejection fraction (EF) than subjects with primary snoring (p < 0.05). SF in moderate-to-severe SDB, mild SDB and primary snoring groups was: 34.3 +/- 5.5%, 36.9 +/- 3.2% and 37.7 +/- 4.4%, respectively, and EF: 66.9 +/- 7.9%, 71.7 +/- 6.4% and 72.3 +/- 5.9%, respectively. OAHI, age, and systolic blood pressure were significant predictors of SF and EF (p<0.01). Conclusions: In children with obstructive SDB, LV systolic function is inversely associated with severity of intermittent upper airway obstruction during sleep. (C) 2010 Elsevier B.V. All rights reserved.