An Integrated Heart Sound–Electrocardiogram Synchronization System for Early Detecting Left Ventricular Systolic Dysfunction in Pediatric Populations

BACKGROUND: Early detection of pediatric left ventricular systolic dysfunction (LVSD) remains challenging in resource-limited settings. This study evaluates a novel synchronized heart sound-electrocardiogram (HS-ECG) system for LVSD detection in underserved pediatric populations. HYPOTHESIS: Cardiac acoustic biomarkers (CABs) enable age-specific early detection of pediatric LVSD. METHODS: This prospective cohort study enrolled 212 children aged 3-16 years, classified into case (LVEF ≤ 55%, n = 80) and control (LVEF > 55%, n = 132) groups with age stratification (3-6 and 7-16 years). All underwent synchronized HS-ECG recording using a high-fidelity wearable device. Signals were processed via wavelet analysis to derive CABs including electromechanical activation time (EMAT), pre - ejection period (PEP), left ventricular ejection time (LVET), left ventricular systolic time (LVST), their rate-corrected values (EMATc, PEPc, LVETc, LVSTc), and the PEP/LVET ratio. Echocardiographic LVEF served as the reference standard. RESULTS: In children aged 3-6 years, EMATc showed strong inverse correlation with LVEF (r = -0.529, p < 0.001) and AUC = 0.821 (cutoff: 11.80%; sensitivity 82.5%, specificity 84.7%). In those aged 7-16 years, EMAT demonstrated superior performance (r = -0.609, p < 0.001; AUC = 0.896; cutoff: 82.50 ms; sensitivity 82.5%, specificity 93.2%). CONCLUSION: The synchronized HS-ECG system provides clinically valuable biomarkers for pediatric LVSD diagnosis, demonstrating distinct age-dependent diagnostic patterns: EMATc shows optimal performance in younger children (3-6 years), while EMAT exhibits superior efficacy in older children (7-16 years).