{
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  "capturedAt": "2026-11-13T05:44:15.527Z",
  "sha256": "6bcfdf8be506e479f586b49dbf4ce13a532c3dea429d5942b0b3522adf1c5ce1",
  "work": {
    "type": "RDN",
    "kind": "note",
    "key": "brozat-2025",
    "id": "TAP-RDN-0086",
    "locale": "en",
    "path": "/research/brozat-2025/",
    "title": "TAP reading note: Systematic Review on HRV Reference Values",
    "description": "The review found no generally accepted HRV reference range that can be applied across populations, metrics and recording protocols. Differences in duration, equipment, age and handling of confounders prevented a defensible pooled normal range.",
    "rights": "© The Allostasis Project. All rights reserved. Reproduction or adaptation requires separate permission, subject to applicable legal exceptions.",
    "version": "1.0",
    "updatedAt": "2026-11-13",
    "editorial": {
      "contentType": "evidence-review",
      "reviewState": "draft",
      "reviewedAt": null,
      "reviewedVersion": null,
      "updatedAt": "2026-11-13",
      "version": "1.0",
      "byline": "team",
      "author": null,
      "reviewer": null,
      "workflow": {
        "ai": {
          "usage": "used",
          "system": "OpenAI Codex",
          "scope": "Source-based synthesis, drafting and translation. Consulted materials and access limits are described in the reading notes.",
          "version": "1.0",
          "tasks": [
            "Literature comparison and evidence extraction",
            "Bilingual explanatory writing and source-linked tables"
          ]
        }
      },
      "revisions": []
    },
    "original": {
      "id": "brozat-2025",
      "title": "Systematic Review on HRV Reference Values",
      "authors": "Maximillian Brozat; Irina Böckelmann; Stefan Sammito",
      "journal": "Journal of Cardiovascular Development and Disease",
      "year": "2025",
      "url": "https://doi.org/10.3390/jcdd12060214",
      "doi": "10.3390/jcdd12060214",
      "pmid": "40558649"
    },
    "references": [
      {
        "id": "brozat-2025",
        "title": "Systematic Review on HRV Reference Values",
        "authors": "Maximillian Brozat; Irina Böckelmann; Stefan Sammito",
        "journal": "Journal of Cardiovascular Development and Disease",
        "year": "2025",
        "url": "https://doi.org/10.3390/jcdd12060214",
        "doi": "10.3390/jcdd12060214",
        "pmid": "40558649"
      }
    ],
    "sections": [
      {
        "id": "finding",
        "title": "What the study found",
        "paragraphs": [
          "The review found no generally accepted HRV reference range that can be applied across populations, metrics and recording protocols. Differences in duration, equipment, age and handling of confounders prevented a defensible pooled normal range."
        ]
      },
      {
        "id": "limits",
        "title": "Scope & limitations",
        "paragraphs": [
          "Reference-value studies from 1989–2022; individual samples ranged from 20 to 84,772, with ages from one day to 99 years.",
          "The search ended on 2 November 2022 despite publication in 2025. The abstract and several totals say 58 studies, whereas methods/results say 57; this count discrepancy remains unresolved. English/German restriction, inconsistent definitions of health and measurement differences constrain coverage. Study reference distributions are not diagnostic thresholds."
        ]
      },
      {
        "id": "sample",
        "title": "Population & sample",
        "paragraphs": [
          "Reference-value studies from 1989–2022; individual samples ranged from 20 to 84,772, with ages from one day to 99 years."
        ]
      },
      {
        "id": "exposure",
        "title": "Exposure or intervention",
        "paragraphs": [
          "Four-database review of studies reporting reference values in healthy participants; ECG durations ranged from 10 seconds to 24 hours and intermediate windows."
        ]
      },
      {
        "id": "outcomes",
        "title": "Outcomes",
        "paragraphs": [
          "Time-domain, frequency-domain and nonlinear HRV metrics; a descriptive review rather than a pooled diagnostic accuracy estimate."
        ]
      },
      {
        "id": "duration",
        "title": "Time frame",
        "paragraphs": [
          "Search on 2 November 2022; published 6 June 2025."
        ]
      },
      {
        "id": "funding",
        "title": "Research funding",
        "paragraphs": [
          "Authors reported no external funding."
        ]
      },
      {
        "id": "conflicts",
        "title": "Research conflicts of interest",
        "paragraphs": [
          "Authors declared no conflicts of interest."
        ]
      },
      {
        "id": "basis",
        "title": "Reading scope",
        "paragraphs": [
          "PMC full text: methods, results, reference-value comparison, discussion and declarations. The 57/58 count discrepancy is retained; the original studies’ full datasets were not reanalysed."
        ],
        "links": [
          {
            "label": "Full text in PubMed Central",
            "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC12194801/"
          }
        ]
      }
    ]
  }
}