Diagnostic Value of Synchronous Heart Sound Electrocardiogram in Children with Postural Tachycardia Syndrome.

Background: Postural tachycardia syndrome (POTS) is a common autonomic dysfunction in children. The head-up test (HUT) or head-up tilt test (HUTT) is typically required to confirm the diagnosis of POTS. This study describes a novel approach to diagnosing POTS in children by simultaneous measurement and analysis of heart sounds and electrocardiogram (ECG) signals using a wearable device. Objective: To evaluate the diagnostic value of synchronous heart sound and ECG monitoring in identifying POTS in children. Methods: This study included a total of 50 children. Twenty-five children with POTS were admitted to the hospital with symptoms of syncope or orthostatic intolerance, while twenty-five children who came to the hospital for a health checkup were included as the control group. All children underwent synchronous phonocardiography and ECG monitoring with wearable devices to simultaneously record heart sounds and ECG signals. Wavelet analysis was used to automatically analyze heart sounds and ECG signals to determine the Electromechanical Activity Time (EMAT). Results: In the POTS group, EMAT decreased significantly from supine to upright position (75.71 ± 9.16 ms vs 70.90 ± 10.86 ms, P = 0.0051), while the change in the control group was not significant (58.92 ± 4.10 ms vs 55.50 ± 9.89 ms, P = 0.100). The difference in EMAT change (upright-supine) was significantly greater in the POTS group (3.39±5.91 ms) than in controls (0.58 ±5.70 ms, P = 0.038).Precision-recall curve (PRC) analysis demonstrated that the average precision (AP) for EMAT in the supine position was 0.84, while the AP for the upright position was 0.88. Conclusion: Simultaneous heart sound and ECG analysis using a wearable device is a simple, noninvasive approach that aids in the diagnosis of pediatric POTS. EMAT serves as a valuable discriminative marker between patient groups.