A healthy heart is not a metronome: an integrative review of the heart's anatomy and heart rate variability

score

1

scope

Paper

status

assessed

randomized Controlled Trial

false

blinding

not-applicable

peer Reviewed

true

basis

Indexed peer-reviewed research; a qualifying randomized controlled design is not established in the reviewed record.

sources

https://pubmed.ncbi.nlm.nih.gov/25324790/ · https://doi.org/10.3389/fpsyg.2014.01040 · https://www.frontiersin.org/articles/10.3389/fpsyg.2014.01040/full

review Scope

Existing publication-specific assessments and bibliographic indexing; no blanket full-text appraisal.

assessed At

2026-10-27

status

unassessed

score

Not recorded

sound

807

language

Not recorded

src-ccd524bfd673

https://www.frontiersin.org/articles/10.3389/fpsyg.2014.01040/full · https://doi.org/10.3389/fpsyg.2014.01040 · https://pubmed.ncbi.nlm.nih.gov/25324790/

sound · language

Heart rate & autonomic · Brain & nervous system · Methods & context

“Physiological coherence is used broadly and includes all of the specific approaches for quantifying the various types of coherence measures, such as cross-coherence (frequency entrainment between respiration, BP, and heart rhythms), or synchronization among systems (e.g., synchronization between various EEG rhythms and the cardiac cycle), auto-coherence (stability of a single waveform such as respiration or HRV patterns), and system resonance.” · “A coherent heart rhythm is defined as a relatively harmonic (sine-wave-like) signal with a very narrow, high-amplitude peak in the LF region of the HRV power spectrum with no major peaks in the VLF or HF regions. Coherence is assessed by identifying the maximum peak in the 0.04–0.26 Hz range of the HRV power spectrum, calculating the integral in a window 0.030 Hz wide, centered on the highest peak in that region, and then calculating the total power of the entire spectrum. The coherence ratio is formulated as: (Peak Power/[Total Power – Peak Power])” · “With practice, people can learn to breathe at their cardiovascular system's resonance frequency. This aligns the three oscillators (baroreflex, HR, and BP) at that frequency and moves the peak frequency from the HF range (≈0.2 Hz) to the LF range (≈0.1 Hz). Breathing at the resonance frequency more than doubles the energy in the LF band (0.04–0.15 Hz). This corresponds to the Institute of HeartMath's heart rhythm coherence, which is associated with a “narrow, high-amplitude, easily visualized peak” from 0.09 to 0.14 Hz” · “The resonance frequency model uses the mechanism of slow breathing at an individual’s resonance frequency, while the psychological coherence model adds and emphasizes the importance of the pattern and stability of vagal afferent traffic as important components of emotional self-regulation. Both approaches have been associated with increased overall HRV over time.” · “There is agreement that the concept of “coherence” in the heart rate signal is observed as a peak in the HRV power spectrum around 0.1 Hz, which reflects resonance frequency of breathing and resonance in the baroreflex. The authors’ “psychophysiological coherence model” advocates biofeedback training that actually creates a maximum of HRV variability at this virtual single frequency.” · “It is known that the power spectrum distribution of normal fluctuations in a healthy heart follows an 1/f pattern, characteristic of fractal signals. So, this leads us to juxtapose Coherence and simplicity vs fractals and complexity.”

score

1

scope

Paper

status

assessed

randomized Controlled Trial

false

blinding

not-applicable

peer Reviewed

true

basis

Indexed peer-reviewed research; a qualifying randomized controlled design is not established in the reviewed record.

sources

https://pubmed.ncbi.nlm.nih.gov/25324790/ · https://doi.org/10.3389/fpsyg.2014.01040 · https://www.frontiersin.org/articles/10.3389/fpsyg.2014.01040/full

review Scope

Existing publication-specific assessments and bibliographic indexing; no blanket full-text appraisal.

assessed At

2026-10-27

sound

807

language

Not recorded

1. key

   sound:ix

   title

   Baroreflex, heart-rate variability and Mayer waves around 0.1 Hz

   collection

   sound

   trust Score

   1

2. key

   language:ix

   title

   Meditation, yoga and biofeedback: heart-rate variability and autonomic regulation

   collection

   language

   trust Score

   2

1. id

   ix-pmid-25324790

   record Id

   pmid-25324790

   title

   A healthy heart is not a metronome: an integrative review of the heart's anatomy and heart rate variability

   journal

   Frontiers in Psychology

   year

   2014

   authors

   Shaffer F, McCraty R, Zerr CL.

   design

   urls

   https://www.frontiersin.org/articles/10.3389/fpsyg.2014.01040/full · https://doi.org/10.3389/fpsyg.2014.01040 · https://pubmed.ncbi.nlm.nih.gov/25324790/

   quotes

   1. 1. text

         “Physiological coherence is used broadly and includes all of the specific approaches for quantifying the various types of coherence measures, such as cross-coherence (frequency entrainment between respiration, BP, and heart rhythms), or synchronization among systems (e.g., synchronization between various EEG rhythms and the cardiac cycle), auto-coherence (stability of a single waveform such as respiration or HRV patterns), and system resonance.”

         emphasis

         false

   2. 1. text

         “A coherent heart rhythm is defined as a relatively harmonic (sine-wave-like) signal with a very narrow, high-amplitude peak in the LF region of the HRV power spectrum with no major peaks in the VLF or HF regions. Coherence is assessed by identifying the maximum peak in the 0.04–0.26 Hz range of the HRV power spectrum, calculating the integral in a window 0.030 Hz wide, centered on the highest peak in that region, and then calculating the total power of the entire spectrum. The coherence ratio is formulated as: (Peak Power/[Total Power – Peak Power])”

         emphasis

         false

   3. 1. text

         “With practice, people can learn to breathe at their cardiovascular system's resonance frequency. This aligns the three oscillators (baroreflex, HR, and BP) at that frequency and moves the peak frequency from the HF range (≈0.2 Hz) to the LF range (≈0.1 Hz). Breathing at the resonance frequency more than doubles the energy in the LF band (0.04–0.15 Hz). This corresponds to the Institute of HeartMath's heart rhythm coherence, which is associated with a “narrow, high-amplitude, easily visualized peak” from 0.09 to 0.14 Hz”

         emphasis

         false

   4. 1. text

         “The resonance frequency model uses the mechanism of slow breathing at an individual’s resonance frequency, while the psychological coherence model adds and emphasizes the importance of the pattern and stability of vagal afferent traffic as important components of emotional self-regulation. Both approaches have been associated with increased overall HRV over time.”

         emphasis

         false

   5. 1. text

         “There is agreement that the concept of “coherence” in the heart rate signal is observed as a peak in the HRV power spectrum around 0.1 Hz, which reflects resonance frequency of breathing and resonance in the baroreflex. The authors’ “psychophysiological coherence model” advocates biofeedback training that actually creates a maximum of HRV variability at this virtual single frequency.”

         emphasis

         false

   6. 1. text

         “It is known that the power spectrum distribution of normal fluctuations in a healthy heart follows an 1/f pattern, characteristic of fractal signals. So, this leads us to juxtapose Coherence and simplicity vs fractals and complexity.”

         emphasis

         false

   citation Count

   807

   source Pages

   67

   targets

   None recorded

   categories

   Heart rate & autonomic · Brain & nervous system · Methods & context

   doi

   10.3389/fpsyg.2014.01040

   pmid

   25324790

   paper Trust Assessment

   score

   1

   scope

   Paper

   status

   assessed

   randomized Controlled Trial

   false

   blinding

   not-applicable

   peer Reviewed

   true

   basis

   Indexed peer-reviewed research; a qualifying randomized controlled design is not established in the reviewed record.

   sources

   https://pubmed.ncbi.nlm.nih.gov/25324790/ · https://doi.org/10.3389/fpsyg.2014.01040 · https://www.frontiersin.org/articles/10.3389/fpsyg.2014.01040/full

   review Scope

   Existing publication-specific assessments and bibliographic indexing; no blanket full-text appraisal.

   assessed At

   2026-10-27

   collection

   sound

   chapter Number

   2

   topic Id

   ix

   topic Title

   Baroreflex, heart-rate variability and Mayer waves around 0.1 Hz

   trust Score

   1

2. id

   language-ix-src-ccd524bfd673

   record Id

   src-ccd524bfd673

   title

   A Healthy Heart is Not a Metronome: An Integrative Review of the Heart's Anatomy and Heart Rate Variability

   journal

   Frontiers in Psychology

   year

   Not recorded

   authors

   design

   urls

   https://www.heartmath.org/research/research-library/basic/a-healthy-heart-is-not-a-metronome · https://doi.org/10.3389/fpsyg.2014.01040

   quotes

   None recorded

   citation Count

   Not recorded

   source Pages

   39

   targets

   None recorded

   categories

   Heart rate & autonomic

   doi

   10.3389/fpsyg.2014.01040

   pmid

   Not recorded

   paper Trust Assessment

   score

   1

   scope

   Paper

   status

   assessed

   randomized Controlled Trial

   false

   blinding

   not-applicable

   peer Reviewed

   true

   basis

   Indexed peer-reviewed research; a qualifying randomized controlled design is not established in the reviewed record.

   sources

   https://pubmed.ncbi.nlm.nih.gov/25324790/ · https://doi.org/10.3389/fpsyg.2014.01040 · https://www.frontiersin.org/articles/10.3389/fpsyg.2014.01040/full

   review Scope

   Existing publication-specific assessments and bibliographic indexing; no blanket full-text appraisal.

   assessed At

   2026-10-27

   collection

   language

   chapter Number

   2

   topic Id

   ix

   topic Title

   Meditation, yoga and biofeedback: heart-rate variability and autonomic regulation

   trust Score

   2

status

unassessed

score

Not recorded

1 · 2

status

open-license

retrieval Available

true

url

https://www.ebi.ac.uk/europepmc/webservices/rest/PMC4179748/fullTextXML

pmcid

PMC4179748

rights

license

http://creativecommons.org/licenses/by/4.0/

statement

Copyright © 2014 Shaffer, McCraty and Zerr. 2014 https://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

sha256

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checked At

2026-10-24