Definition and research guide
This page combines a MeSH definition, publication statistics and selected research abstracts. It is a starting point for reading the literature, not a medical textbook or a systematic evidence review.
Content available: 4 complete abstracts (558 words), 10 references. Full article text is not stored or reproduced here; follow the PMID, DOI or PMC links to read the original sources and their access terms.
Definition
Cardiac arrhythmias that are characterized by excessively slow heart rate, usually below 50 beats per minute in human adults. They can be classified broadly into sinoatrial node dysfunction and atrioventricular block.
Definition: NLM Medical Subject Headings (MeSH) scope note (Public domain (U.S. National Library of Medicine); attribution requested). View the MeSH record.
Also known as: Bradycardias; Bradyarrhythmia; Bradyarrhythmias.
Where it fits in the MeSH classification
- Broader topics
- Arrhythmias, Cardiac
Related concepts
- Heart Rate
- Sinoatrial Node
- Atrioventricular Block
Research landscape
PubMed indexes 12,394 records tagged with the MeSH heading “Bradycardia” (counts retrieved 2026-10-29). 1,465 of them (11.8%) were published from 2020 onward, and the busiest period so far is through 1999 with 6,101 records.
Reviews account for 1,178 records (9.5%) and meta-analyses for 122. Randomized controlled trials number 466 (3.8%) as a share of all records on the topic.
Show the data
| Period | Records |
|---|---|
| through 1999 | 6,101 |
| 2000-2009 | 2,356 |
| 2010-2019 | 2,472 |
| 2020 onward | 1,465 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 1,178 | 9.5% |
| Meta-analyses | 122 | 1.0% |
| Randomized controlled trials | 466 | 3.8% |
Method: PubMed query "Bradycardia"[MeSH Terms] with publication-type and date filters, retrieved 2026-10-29.
Reading the evidence in cardiovascular medicine
Cardiovascular medicine has an unusually large body of randomized trials, so the type of outcome matters: hard clinical events such as death, heart attack and stroke carry more weight than changes in blood pressure, cholesterol or imaging markers that only predict risk. Observational studies can show associations but are confounded by age, lifestyle and other illness. Check whether a result is about prevention or treatment, the baseline risk of participants, and the absolute rather than only the relative size of any benefit.
Evidence from open-access studies
These open-access studies come from PubMed’s best-match results for this heading (papers whose main topic it is), ranked here by citation count, with one recent addition. Each abstract is reproduced in full under its recorded open licence so that you can read the authors’ own words. They illustrate the literature; they are not a systematic summary of it. Citation counts measure attention, not reliability or clinical benefit.
Cardioneuroablation for the treatment of reflex syncope and functional bradyarrhythmias: A Scientific Statement of the European Heart Rhythm Association (EHRA) of the ESC, the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS) and the Latin American Heart Rhythm Society (LAHRS) [1]
Abstract reading summary — source excerpts
- Opening excerpt
- Cardioneuroablation has emerged as a potential alternative to cardiac pacing in selected cases with vasovagal reflex syncope, extrinsic vagally induced sinus bradycardia-arrest or atrioventricular block.
- Closing excerpt
- This document aims to review and interpret available scientific evidence and provide a summary position on the topic.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (81 words)
Cardioneuroablation has emerged as a potential alternative to cardiac pacing in selected cases with vasovagal reflex syncope, extrinsic vagally induced sinus bradycardia-arrest or atrioventricular block. The technique was first introduced decades ago, and its use has risen over the past decade. However, as with any intervention, proper patient selection and technique are a prerequisite for a safe and effective use of cardioneuroablation therapy. This document aims to review and interpret available scientific evidence and provide a summary position on the topic.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 39082698 · DOI · PMC11350289
Systemic inflammation indicators and risk of incident arrhythmias in 478,524 individuals: evidence from the UK Biobank cohort [2]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundThe role of systemic inflammation in promoting cardiovascular diseases has attracted attention, but its correlation with various arrhythmias remains to be clarified.
- Closing excerpt
- Active systemic inflammation management might have favorable effects in reducing the arrhythmia burden and further randomized controlled studies are needed.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (185 words)
BackgroundThe role of systemic inflammation in promoting cardiovascular diseases has attracted attention, but its correlation with various arrhythmias remains to be clarified. We aimed to comprehensively assess the association between various indicators of systemic inflammation and atrial fibrillation/flutter (AF), ventricular arrhythmia (VA), and bradyarrhythmia in the UK Biobank cohort.MethodsAfter excluding ineligible participants, a total of 478,524 eligible individuals (46.75% male, aged 40-69 years) were enrolled in the study to assess the association between systemic inflammatory indicators and each type of arrhythmia.ResultsAfter covariates were fully adjusted, CRP levels were found to have an essentially linear positive correlation with the risk of various arrhythmias; neutrophil count, monocyte count, and NLR showed a non-linear positive correlation; and lymphocyte count, SII, PLR, and LMR showed a U-shaped association. VA showed the strongest association with systemic inflammation indicators, and it was followed sequentially by AF and bradyarrhythmia.ConclusionsMultiple systemic inflammatory indicators showed strong associations with the onset of AF, VA, and bradyarrhythmia, of which the latter two have been rarely studied. Active systemic inflammation management might have favorable effects in reducing the arrhythmia burden and further randomized controlled studies are needed.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 36855116 · DOI · PMC9976398
Cyclic bouts of extreme bradycardia counteract the high metabolism of frugivorous bats [3]
Abstract reading summary — source excerpts
- Opening excerpt
- Active flight requires the ability to efficiently fuel bursts of costly locomotion while maximizing energy conservation during non-flying times.
- Closing excerpt
- bilobatum highlights the fundamental role of ecological pressures on integrative energetic networks and the still poorly understood energetic strategies of animals in the tropics.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (144 words)
Active flight requires the ability to efficiently fuel bursts of costly locomotion while maximizing energy conservation during non-flying times. We took a multi-faceted approach to estimate how fruit-eating bats (Uroderma bilobatum) manage a high-energy lifestyle fueled primarily by fig juice. Miniaturized heart rate telemetry shows that they use a novel, cyclic, bradycardic state that reduces daily energetic expenditure by 10% and counteracts heart rates as high as 900 bpm during flight. Uroderma bilobatum support flight with some of the fastest metabolic incorporation rates and dynamic circulating cortisol in vertebrates. These bats will exchange fat reserves within 24 hr, meaning that they must survive on the food of the day and are at daily risk of starvation. Energetic flexibly in U. bilobatum highlights the fundamental role of ecological pressures on integrative energetic networks and the still poorly understood energetic strategies of animals in the tropics.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 28923167 · DOI · PMC5605195
Scoping Review on True and Relative Bradycardia in Trauma: How to Approach Bradycardia in Traumatic Brain Injury [4]
Abstract reading summary — source excerpts
- Opening excerpt
- Brain-heart interactions have garnered considerable interest in the landscape of traumatic brain injury (TBI).
- Closing excerpt
- Physicians should approach patients presenting with RB with a high index of suspicion and timely management.
- Interpretation limits
- Verbatim excerpts from the authors’ abstract; the closing excerpt may describe a finding, limitation or recommendation. Design, population, effect size and uncertainty have not been independently extracted or appraised. Read the complete abstract and linked paper before interpreting the findings.
Read complete abstract (148 words)
Brain-heart interactions have garnered considerable interest in the landscape of traumatic brain injury (TBI). This scoping review focused on bradycardia caused by high intracranial pressure (ICP), brainstem injury, autonomic imbalance, hypothalamic-pituitary-adrenal axis disruption, or massive bleeding. The latter condition is attributed to a physiological phenomenon called relative bradycardia (RB). True bradycardia results from underlying physiological or pathological cardiac disorders, whereas RB has different definitions and implications in medical and surgical settings. The former reflects pulse-temperature dissociation, while the latter reflects pulse-pressure dissociation. However, it can reflect an abnormal neurological response called the Cushing reflex. Therefore, bradycardia may indicate imminent shock after TBI associated with torso injuries or high ICP following severe isolated TBI. RB is underrecognized and underappreciated in emergency settings. This review investigated whether RB affects patient survival and neurological function. Physicians should approach patients presenting with RB with a high index of suspicion and timely management.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 42043702 · DOI · PMC13121324
Key reviews and meta-analyses
The most cited review-type papers among PubMed’s best-match results for this heading, listed with bibliographic details only. Follow the links for the full text and access terms.
- Research article 2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society [5]
- Research article Propofol infusion syndrome [6]
- Research article 2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society [7]
- Research article Perioperative bradycardia and asystole: relationship to vasovagal syncope and the Bezold-Jarisch reflex [8]
- Research article The evaluation and management of bradycardia [9]
- Research article Propofol and bradycardia: causation, frequency and severity [10]
References
- Aksu T, Brignole M, Calo L, Debruyne P, Di Biase L, Deharo JC, et al.. Cardioneuroablation for the treatment of reflex syncope and functional bradyarrhythmias: A Scientific Statement of the European Heart Rhythm Association (EHRA) of the ESC, the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS) and the Latin American Heart Rhythm Society (LAHRS). . 2024. PMID 39082698 · DOI · PMC11350289
- Yang X, Zhao S, Wang S, Cao X, Xu Y, Yan M, et al.. Systemic inflammation indicators and risk of incident arrhythmias in 478,524 individuals: evidence from the UK Biobank cohort. . 2023. PMID 36855116 · DOI · PMC9976398
- O'Mara MT, Wikelski M, Voigt CC, Ter Maat A, Pollock HS, Burness G, et al.. Cyclic bouts of extreme bradycardia counteract the high metabolism of frugivorous bats. . 2017. PMID 28923167 · DOI · PMC5605195
- El-Menyar A, Khan NA, Abid AR, Elmenyar E, Al-Thani H. Scoping Review on True and Relative Bradycardia in Trauma: How to Approach Bradycardia in Traumatic Brain Injury. . 2026. PMID 42043702 · DOI · PMC13121324
- Kusumoto FM, Schoenfeld MH, Barrett C, Edgerton JR, Ellenbogen KA, Gold MR, et al.. 2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Circulation. 2019. PMID 30586772 · DOI
- Kam PC, Cardone D. Propofol infusion syndrome. Anaesthesia. 2007. PMID 17567345 · DOI
- Kusumoto FM, Schoenfeld MH, Barrett C, Edgerton JR, Ellenbogen KA, Gold MR, et al.. 2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol. 2019. PMID 30412709 · DOI
- Kinsella SM, Tuckey JP. Perioperative bradycardia and asystole: relationship to vasovagal syncope and the Bezold-Jarisch reflex. Br J Anaesth. 2001. PMID 11573596 · DOI
- Mangrum JM, DiMarco JP. The evaluation and management of bradycardia. N Engl J Med. 2000. PMID 10706901 · DOI
- Tramèr MR, Moore RA, McQuay HJ. Propofol and bradycardia: causation, frequency and severity. Br J Anaesth. 1997. PMID 9215013 · DOI
About this article
- Sources
- NLM Medical Subject Headings (definition, synonyms); NCBI PubMed (counts, identifiers); Europe PMC (open-access abstracts and citation counts).
- Verification
- Every reference was resolved against PubMed on 2026-10-31; title, year and DOI matched.
- Review state
- automated source verified; no human expert review has been recorded yet.
- Version
- 1, last updated 2026-10-29.
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Evidence strength
EvidenceHelix's computed view of the study designs behind this topic: how common meta-analyses, randomized trials and reviews are, how recent the literature is, and a plain-language reading. It describes the design mix of the literature. It is not a quality appraisal of any study, and it is not medical advice.