Electrocardiographic Changes Following Pediatric Adenotonsillectomy for Obstructive Sleep-Disordered Breathing: A Pilot Prospective Study

Background/Objectives: Adenotonsillar hypertrophy (ATH) is the primary driver of pediatric obstructive sleep-disordered breathing (OSDB), potentially leading to cardiac remodeling. This study evaluated the impact of adenotonsillectomy (AT) on electrocardiographic (ECG) parameters and correlated these changes with sleep metrics. Methods: This prospective study evaluated ECG parameters (P-wave and QRS morphology) in children (>3 years) with symptomatic ATH before and three months after AT. A subset underwent sleep analysis via Cardiopulmonary Coupling (CPC) at both time points. Pre- and postoperative data were compared using paired t-tests and Linear Mixed Models (LMMs). The link between ECG and sleep modifications was also analyzed using Pearson and Spearman correlations of their respective variations (Δ). Results: Significant reductions were observed in the maximum RR interval (p = 0.027). Mean P-wave duration significantly shortened (84.40 ± 6.51 ms to 81.20 ± 3.32 ms; p = 0.043) and mean amplitude increased (0.076 ± 0.008 mV to 0.080 ± 0.004 mV; p < 0.001). Mean, minimum, and maximum QRS amplitudes increased significantly (p ≤ 0.018). Exploratory LMM confirmed that these modifications remained significant after adjusting for age and sex. Furthermore, post hoc analyses revealed that Δ QRS maximum amplitude exhibited negative correlations that survived false discovery rate (FDR) adjustment with Δ AHI 4% max (r = −0.727, p = 0.045), Δ ODI 3% max (r = −0.765, p = 0.045), Δ ODI 4% mean (r = −0.819; p = 0.033), and Δ maximal hypoxic burden (r = −0.730; p = 0.045). Conclusions: AT may alter ECG parameters. QRS amplitude increments correlated well with a decrease in nocturnal respiratory events. These findings may represent preliminary ECG changes associated with postoperative respiratory improvement. Larger controlled studies are needed to determine whether these ECG parameters can serve as markers of post-operative cardiopulmonary recovery.