5HRV

Evidence

Peer-reviewed references supporting the measurement, interpretation and clinical application of five-minute HRV.

The 5HRV method is built on a foundation of published research spanning measurement standards, population reference values, physiological interpretation and clinical applications. The following references are organized by topic area. This list is not exhaustive; additional peer-reviewed literature should be consulted for specific clinical populations and research questions.

Standards and methodology

  1. Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Heart rate variability: standards of measurement, physiological interpretation and clinical use. Circulation. 1996;93:1043–1065.Foundational standard for HRV measurement and analysis.
  2. Shaffer F, Ginsberg JP. An overview of heart rate variability metrics and norms. Frontiers in Public Health. 2017;5:258. DOI: 10.3389/fpubh.2017.00258Comprehensive overview of time-domain and frequency-domain HRV metrics, measurement conditions and considerations for clinical interpretation.

Population reference values

  1. Brinth LS, Jørgensen T, Mehlsen J, et al. Normative values of short-term heart rate variability in a cross-sectional study of a Danish population: the DanFunD study. Scandinavian Journal of Public Health. 2024;52:48–57. DOI: 10.1177/14034948221124020Provides the age- and sex-stratified RMSSD and SDNN reference percentiles used in the 5HRV calculator.

Physiological interpretation

  1. Billman GE. The LF/HF ratio does not accurately measure cardiac sympatho-vagal balance. Frontiers in Physiology. 2013;4:26. DOI: 10.3389/fphys.2013.00026Critical review demonstrating that LF/HF does not provide a direct quantitative measurement of sympathetic–parasympathetic balance.
  2. Hirsch JA, Bishop B. Respiratory sinus arrhythmia in humans: how breathing pattern modulates heart rate variability. American Journal of Physiology. 1981;241:H620–H629. DOI: 10.1152/ajpheart.1981.241.4.H620Demonstrates that respiratory rate and depth significantly influence HF power and related HRV metrics.

Recording technology

  1. Plews DJ, Scott B, Altini M, Wood M, Kilding AE, Laursen PB. Comparison of Heart-Rate-Variability Recording With Smartphone Photoplethysmography, Polar H7 Chest Strap, and Electrocardiography. International Journal of Sports Physiology and Performance. 2017;12(10):1324–1328. DOI: 10.1123/ijspp.2016-0668Historical supporting evidence for the earlier Polar H7 chest strap. Compares HRV metrics derived from ECG, chest strap and PPG.

Polar H10 RR-interval validity

Polar H10 chest-strap RR intervals have shown very high agreement with ECG-derived values for common linear HRV parameters, including mean RR, RMSSD and SDNN, in controlled recordings. This supports its use for standardized short-term HRV measurement when signal quality is adequate and artefacts are handled appropriately. Device validity does not remove the need for consistent posture, minimal movement, spontaneous breathing and rhythm suitability.

  1. Gilgen-Ammann R, Schweizer T, Wyss T. RR interval signal quality of a heart rate monitor and an ECG Holter at rest and during exercise. European Journal of Applied Physiology. 2019;119:1523–1532. DOI: 10.1007/s00421-019-04142-5Demonstrates very high agreement of Polar H10 RR intervals with ECG Holter-derived values for mean RR, RMSSD and SDNN.
  2. Schaffarczyk M, Rogers B, Reer R, Gronwald T. Validity of the Polar H10 sensor for heart rate variability analysis during resting state and different exercise intensities. Frontiers in Physiology. 2022;13:1003760. DOI: 10.3389/fphys.2022.1003760Confirms validity of Polar H10-derived HRV parameters in resting and exercise conditions.

Clinical and research applications

  1. Nelson MJ, Bahl JS, Buckley JD, Thomson RL, Davison K. Evidence of altered cardiac autonomic regulation in myalgic encephalomyelitis/chronic fatigue syndrome: a systematic review and meta-analysis. Medicine (Baltimore). 2019;98(43):e17600. DOI: 10.1097/MD.0000000000017600Systematic review documenting reduced HRV in ME/CFS populations.
  2. Swai J, Hu Z, Zhao X, Rugambwa T, Ming G. Heart rate and heart rate variability comparison between postural orthostatic tachycardia syndrome versus healthy participants: a systematic review and meta-analysis. BMC Cardiovascular Disorders. 2019;19:320. DOI: 10.1186/s12872-019-01298-ySystematic review and meta-analysis of HRV differences between POTS patients and healthy controls.
  3. Benarroch EE. Postural tachycardia syndrome: a heterogeneous and multifactorial disorder. Mayo Clinic Proceedings. 2012;87:1214–1225. DOI: 10.1016/j.mayocp.2012.08.013Reviews the pathophysiology of POTS including autonomic, cardiovascular and neural mechanisms.
  4. Barizien N, Le Guen M, Russel S, et al. Clinical characterization of dysautonomia in long COVID-19 patients. Scientific Reports. 2021;11:14042. DOI: 10.1038/s41598-021-93546-5Assessed autonomic function in post-COVID patients and called for future studies using direct HRV measurement.

Project documentation

The following is project documentation by the 5HRV author. It has not been peer-reviewed.

  1. Gielen W. 5HRV Autonomic Pattern Score: a single numerical index for five-minute heart rate variability interpretation. Zenodo. 2026. DOI: 10.5281/zenodo.21558647Describes the derivation and interpretation of the 5HRV Autonomic Pattern Score used in the 5HRV calculator.

Reference implementation and explanatory framework adapted from the five-minute HRV teaching material of Willem Gielen, Cardiologist and Internist. This reference list is not exhaustive; additional peer-reviewed literature should be consulted for specific study populations and research questions.