Heart Rate Variability in Patients With Vasodepressor Syncope: a Comparison Between Those With and Without Epilepsy During Tilt Table Testing
Year: 2026
Type: article
Study design: Observational Study
Abstract: Background: The main causes of transient loss of consciousness are neurological emergencies involving seizures and syncope. The two clinical conditions can coexist, and both may present with autonomic dysfunction. Aims: to evaluate heart rate variability (HRV) in participants with vasovagal syncope, comparing those with epilepsy (group A) and those without epilepsy (group B), all without structural heart disease or conditions affecting HRV, and matched for sex and age, who undergoing the tilt table testing (HUTT). Methods: 24 patients were included, 8 from group A, undergoing HUTT at 70º, under Holter monitoring. HRV was performed using Fourier transformation [high-frequency (HF) and low-frequency (LF) components and the LF/HF ratio] in the supine position and at the 10th minute of HUTT. Only those with a vasodepressor phenotype who showed a positive response were included. Results: the mean age was 39.3 years (A) and 32.3 years (B), 15 females. There was no difference between the groups regarding the presence of prodromes, physical injury, Calgary score, blood pressure, heart rate and vasovagal response to HUTT. Log-transformed LF was 2.6 ms2 in group A and 3.0 in group B, p=0.02 (supine position); and LF/HF was 2.6 and 5.7, respectively, p=0.01 (HUTT). There was a reduction in the HF component and an increase in the LF/HF ratio with inclination (p < 0.0001 for both). Conclusions: Sympathetic-vagal activation was lower in participants with epilepsy and syncope compared to those without epilepsy and with syncope. There was no influence of premonitory signs, Calgary score, hemodynamic data, or HUTT positivity.
Institution: Universidade Federal de Minas Gerais
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7169885883