Changes in EEG and ECG signal connectivity during tilt-table testing in healthy males
Mikhail Yu. Novikov1, Maxim O. Zhuravlev1,2, Anton R. Kiselev1; 1National Medical Research Center for Therapy and Preventive Medicine, Moscow, Russia; 2Saratov State University, Saratov, Russia
Abstract
The passive head-up tilt test serves as a valuable tool for examining vasovagal and autonomic cardiovascular responses to orthostatic stress. Current research primarily focuses on syncopal and presyncopal states, while the analysis of electroencephalographic (EEG) and electrocardiographic (ECG) signals typically employs visual inspection or basic spectral analysis methods.
The aim of our study was to investigate EEG-ECG synchronization dynamics during passive orthostasis in healthy young adults using continuous wavelet transform (CWT) and wavelet bicoherence (WB) analysis.
Nineteen healthy male volunteers underwent a 45° passive head-up tilt test with simultaneous EEG and ECG recording. Upon tilting, a significant increase in heart rate was observed (from 1.0–1.05 Hz to 1.3–1.4 Hz), while no statistically significant changes were detected in traditional EEG spectral bands (delta to gamma). WB analysis revealed frequency-dependent modulation of EEG-ECG connectivity: synchronization increased in the low-frequency range (0.25–0.75 Hz) but decreased in the higher frequency range (0.75–1.5 Hz). The most pronounced changes were observed in occipital and frontal EEG leads.
These findings demonstrate that orthostatic stress alters neurocardiac coupling even in the absence of syncope, with distinct dynamics in low- and high-frequency ranges. Enhanced low-frequency synchronization may reflect adaptive autonomic regulation mechanisms, while reduced high-frequency connectivity could indicate physiological resource redistribution. This study presents a novel approach for analyzing subtle neurocardiac interactions and establishes baseline EEG-ECG coupling patterns during passive orthostasis. Further research should explore these processes in larger cohorts, including patients with various autonomic regulation disorders and cardiovascular diseases.
The work was supported by the Russian Science Foundation, project No. 24-24-00333.
Speaker
Maxim O. Zhuravlev
National Medical Research Center for Therapy and Preventive Medicine, Moscow
Russia
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