Clinical significance of Q-TC interval in children with sleep-disordered breathing

Abstract

Aim: We investigated the usefulness of ECG (Q-Tc interval) in determining the optional treatment modality for pediatric Sleep disordered breathing (SDB). METHOD: Fifty-six children presenting with snoring and associated symptoms of obstructive SDB had adenotonsillectomy (A&T) as an optional treatment modality. All studied children had ECG as routine preoperative evaluation in the absence of polysomnographic facilities. At 12 weeks post-adenotonsillectomy ECG was repeated. A Q-Tc interval = or >0.43 was regarded as prolonged. Duration of study was 4 years (September 2002 to August 2006). RESULTS: There was disappearance of symptoms in 98.21 % of children by the second week following A&T. At 12 weeks post-A&T only 26 (46.42%) of patients were available for ECG re-evaluation. Mean pre-op versus post-op Q-Tc was 0.4482 and 0.3932 (t -5.484, df 25, p=0.000.) while mean heart rate was 106.15 and 105.19 (t -.179, df 25, p=0.859.). Adenotonsillectomy resulted in a reversal of prolonged Q-Tc to within the normal range. Five (19.23%) of the children with normal Q-Tc 0.39, 0.41, 0.40, 0.41 and 0.35 preoperatively assumed even lower values post operatively (0.37, 0.40, 0.39, 0.406 and 0.32 respectively). There was no statistical correlation between heart rates and Q-Tc intervals in the pre and post adenotonsillectomy patients. (Pearson correlation; -.058, P = 0.389 and -.266, p = .095 respectively). CONCLUSION: Prolonged Q-Tc interval can be a reasonable pointer to the severity of SDB and its correction is an objective assessment of adenotonsillectomy as an effective treatment option for childhood SDB. Global Journal of Mathematical Sciences Vol. 6 (1) 2007: pp. 41-45