Abstract
BACKGROUND: Ventricular septal defect (VSD) is one of the most common congenital heart diseases in children, accounting for 20%-25% of all congenital heart defects (CHDs). Current clinical diagnostic methods for VSD mainly include electrocardiography (ECG), echocardiography, and chest x-ray, among which echocardiography is the "gold standard" for evaluating the clinical significance of defects and determining the need for intervention. This study aims to explore the application value of synchronous monitoring technology in the differential diagnosis of pediatric VSD (especially subtype distinction) by comparing the phonocardiogram-electrocardiogram characteristics between membranous and muscular VSD in children. OBJECTIVE: To investigate the diagnostic value of synchronous phonocardiogram-electrocardiogram (PCG-ECG) monitoring in pediatric ventricular septal defect (membranous vs. muscular subtypes) and provide evidence for its clinical application. METHODS: A total of 59 children with suspected VSD who visited the Pediatric Cardiovascular Department of our hospital from January 2023 to June 2025 were enrolled (a single-center prospective cohort with consecutive sampling). All children underwent synchronous PCG-ECG monitoring (simultaneous recording of ECG and phonocardiogram) and transthoracic color Doppler echocardiography (hereinafter referred to as "echocardiography"). Using echocardiography as the "gold standard", the differences in electromechanical activation time (EMAT) between the two groups were compared, and the diagnostic efficacy of synchronous monitoring for VSD subtypes (membranous/muscular) was analyzed. VSD subtypes were classified based on anatomical location: membranous defects (perimembranous type, subcristal type) and muscular defects (single, multiple). RESULTS: Synchronous analysis of heart sounds and ECG using wearable devices is a simple and non-invasive method. Wavelet analysis technology is employed to automatically detect heart sound and ECG signals, thereby determining EMAT, which provides key clues for the differential diagnosis of pediatric VSD (especially membranous and muscular subtypes). It serves as an important supplement to echocardiography-especially valuable in primary medical care or preliminary screening, where echocardiography may be limited by equipment and operator experience.