RT Journal Article
T1 Nocturnal Heart Rate Variability in Unexplained Syncope and Sleep Apnea-The SINCOSAS Study
A1 Muñoz Martínez, María José
A1 Casal Guisande, Manuel
A1 Sopeña Pérez-Argüelles, Bernardo
A1 Torres Durán, María
A1 García Campo, Enrique
A1 Corbacho Abelaira, Dolores
A1 Souto Alonso, Ana
A1 Fernández Villar, Alberto
K1 Sleep apnea
K1 Syncope
K1 Heart rate variability
AB Background/Objectives: Heart rate variability (HRV) reflects autonomic nervous system modulation and may be altered in both unexplained syncope and obstructive sleep apnea (OSA). However, the nocturnal autonomic patterns underlying these conditions and their coexistence remain poorly understood. This study aimed to characterize nocturnal autonomic modulation in patients with unexplained syncope, OSA, or both, compared with individuals without these conditions. Methods: In this multicenter, cross-sectional, comparative study, 304 adults were assigned to four groups: controls (no syncope or OSA), OSA without syncope, syncope without OSA, and syncope with OSA. Time- and frequency-domain HRV parameters were derived from overnight respiratory polygraphy and compared across groups. Results: OSA was associated with increased root mean square of successive differences (RMSSD) and reduced low-frequency (LF) power, indicating enhanced vagal activity and lower nocturnal sympathetic tone. Syncope was characterized by further reductions in sympathetic indices (LF and very low frequency, VLF) with increased RMSSD, suggesting blunted sympathetic reserve. Patients with both conditions exhibited a mixed autonomic profile-elevated overall HRV with concurrent reductions in both sympathetic and parasympathetic components-indicating more profound dysautonomia despite milder OSA severity. Conclusions: OSA and syncope show distinct nocturnal autonomic patterns, and their coexistence leads to deeper autonomic imbalance. Incorporating nocturnal HRV analysis into routine polygraphy may improve pathophysiological stratification of unexplained syncope and identify clinically significant OSA.
PB MDPI
YR 2025
FD 2025-11-05
LK https://hdl.handle.net/10347/44916
UL https://hdl.handle.net/10347/44916
LA eng
NO Muñoz-Martínez, M.-J.; Casal-Guisande, M.; Sopeña, B.; Torres-Durán, M.; García-Campo, E.; Corbacho-Abelaira, D.; Souto-Alonso, A.; Fernández-Villar, A. Nocturnal Heart Rate Variability in Unexplained Syncope and Sleep Apnea—The SINCOSAS Study. J. Clin. Med. 2025, 14, 7864. https://doi.org/10.3390/ jcm14217864
NO This research was funded by the Galician Society of Respiratory Pathology (Sociedade Galega de Patoloxía Respiratoria, SOGAPAR).
DS Minerva
RD 30 abr 2026