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Tilt Testing with Combined Lower Body Negative Pressure: a "Gold Standard" for Measuring Orthostatic Tolerance
Published on: March 21, 2013
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Long COVID Patients with Orthostatic Intolerance Have Reduced Heart Rate Variability and Preserved Physiological
J Antonio González-Hermosillo González1, Claudia Lerma2, Dulce Andrea Celestino Montelongo1
1Department of Cardiovascular Dysautonomia, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City 14080, Mexico.
Biology
|January 10, 2026
Summary
Long COVID patients with orthostatic intolerance showed reduced resting heart rate variability (HRV). However, an active orthostatic test did not reveal autonomic dysregulation, suggesting potential recovery of cardiac autonomic modulation.
Area of Science:
- Cardiology
- Neurology
- Infectious Diseases
Background:
- Long COVID is associated with persistent symptoms, including orthostatic intolerance.
- Autonomic dysfunction is a suspected mechanism underlying these symptoms.
Purpose of the Study:
- To evaluate heart rate variability (HRV) at rest and during orthostatic challenge in long COVID patients with orthostatic intolerance.
- To determine if autonomic dysregulation is present in this cohort.
Main Methods:
- Cross-sectional, observational study of 60 participants (31 long COVID, 15 infected, 14 controls).
- Continuous electrocardiograms recorded HRV in supine and active standing positions.
- Analysis of time-domain HRV indices (SDNN, RMSSD, SD1, SD2).
Main Results:
- Long COVID patients exhibited lower resting HRV (SDNN, RMSSD, SD1, SD2) compared to controls.
- No significant differences in other HRV indices at rest.
- Active orthostatic testing revealed similar changes in HRV indices between long COVID and control groups.
Conclusions:
- Reduced resting HRV in long COVID patients suggests potential lingering cardiac autonomic effects.
- Active orthostatic challenge did not demonstrate autonomic dysregulation, possibly due to recovery over time post-infection.
- Further research may explore other autonomic testing methods or earlier intervention.
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