P-wave dispersion as a simple tool for screening childhood obstructive sleep apnea syndrome

Introduction: The gold standard for the diagnosis of childhood obstructive sleep apnea syndrome (OSAS) diagnosis is polysomnography; however, electrocardiography (ECG) may provide a simpler alternative. P-wave dispersion (PWD), the difference between the maximum and minimum P-wave duration measured by 12-lead ECG, is increased in adult OSAS but has not been researched in childhood OSAS. The aims of this study were to determine the PWD and cut-off value for the diagnosis of childhood OSAS and its association with severity. Methods: A total of 77 children with confirmed OSAS and 44 control participants underwent surface 12-lead ECG. P-wave duration was measured using a digital caliper by a researcher blinded to the groups. Results: Median (interquartile range) PWD in children with OSAS (median age = 82.8 months, range = 24–194 months) was significantly higher than that in the control group (median age = 73.4 months, range = 12–156 months): 38.3 (29.7–50.5) vs 25.5 (20.5–30.5) milliseconds, respectively (p < 0.0001). Subgroup analysis according to OSAS severity categorized by the apnea–hypopnea index from polysomnography demonstrated that PWD in the severe OSAS group (n = 24) was significantly higher than that in the mild-to-moderate OSAS group (n = 53): 48.5 (34.7–67.4) vs 35.5 (28.2–47.8) milliseconds, respectively (p = 0.006). A cut-off value of PWD at 26.5 ms from the receiver operating characteristic curve for the diagnosis showed the area under the curve to be 0.839, with a sensitivity of 89.6% and a specificity of 61.4%. Conclusion: PWD was significantly increased in children with OSAS, particularly in severe cases. PWD could be a useful tool for screening childhood OSAS.