Introduction:
Obstructive sleep apnea (OSA) is associated with cardiac dysfunction in children without congenital heart disease (CHD). Children with CHD are at increased risk for OSA and may be susceptible to further cardiovascular consequences due to OSA but the extent and nature of such cardiovascular effects of OSA are unknown.
Methods:
Children (6-17 years old) with corrected CHD without current cyanosis or Down syndrome were recruited from pediatric cardiology clinic. Home sleep tests were done to determine the presence and severity of OSA. OSA was defined as an obstructive apnea hypopnea index (oAHI) ≥1. Mild OSA was defined as an oAHI of ≥1 to <5 and moderate OSA was defined as an oAHI of ≥5 to <10. Standard clinically indicated echocardiograms were performed in clinic. Echocardiographic findings were compared between children with CHD with and without comorbid OSA using t-tests, Wilcoxon-sign rank tests as well as linear or logistic regression as appropriate.
Results:
Thirty-two children had sleep study and echocardiographic data available. OSA was present in 18 children (56%). OSA was mild in 89% and moderate in 11% of cases. There were no significant differences in age, body mass index, CHD severity, gender or ethnicity between children with and without OSA. Children with OSA had larger height-indexed right ventricular end-diastolic diameter (RVDi) compared to those without OSA (median 1.35, 95% CI 1.09, 1.56 vs. 1.21, 95% CI 1.01, 1.57; p=0.04). Children with moderate OSA had a reduced left ventricular shortening fraction compared to both those with mild OSA and no OSA (30.0 ± 6.1% vs. 38.7 ± 4.4%; p=0.009 and 39.2 ± 3.6%; p=0.007, respectively). Children with moderate OSA had increased left ventricular end-systolic diameter compared to those with mild OSA and no OSA (3.4 ± 0.4 cm vs. 2.5 ± 0.4; p=0.007 and 2.4 ± 0.5; p=0.001, respectively). Children with an RVDi above the median were seven times more likely to have OSA than those with an RVDi below the median (odds ratio 6.9.; 95% CI 1.3, 35; p=0.02).
Conclusions:
OSA is associated with changes in cardiac morphology and reduced contractility in children with CHD. Additionally, the presence of right ventricular dilation may suggest the need for OSA evaluation in children with CHD.
Postoperative ventricular tachycardia after the repair of congenital heart disease necessitating right ventricular outflow reconstruction.
