Participants
All children (0 – 18 years of age) who had echocardiogram and PSG
performed within 6 months of one another were included in the study.
Echocardiograms were reviewed by JW and EE and the cohort was divided
into groups with (+HF) and without heart failure (-HF). The +HF group
was defined by left ventricular ejection fraction (LVEF) of ≤45% or
moderate to severe cardiac dysfunction. The -HF group was defined by
LVEF of ≥58% or normal cardiac function and therefore was deemed
appropriate for the control group15. Values in the
intermediate range were excluded to ensure that the population being
studied had significant enough cardiac dysfunction to confidently
separate them from the controls. Exclusion criteria included structural
congenital heart disease with right to left shunting, neurological
conditions associated with CSA such as Arnold Chiari malformation,
congenital central hypoventilation syndrome, patients on non-invasive
ventilation or tracheostomy at the time of PSG, and patients with
inadequate sleep time defined by total sleep time less than 120 minutes.
All patient charts with test data in the study time period were reviewed
with 50,144 children identified and screened for eligibility. Figure 1
shows the screening process for the study. The initial cohort was
screened for individuals with both PSG and echocardiogram within 6
months of each other before being divided into +HF and -HF groups based
on echocardiogram results. To limit the control cohort to a reasonable
size, we only included data on children with -HF from January 1, 2019
through December 31, 2019. Exclusion criteria were then applied with 120
patients ultimately confirmed to be eligible and included in the study.