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 (842 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
A condition caused by dysfunctions related to the sinoatrial node including impulse generation (cardiac sinus arrest) and impulse conduction (sinoatrial exit block). It is characterized by persistent bradycardia, chronic atrial fibrillation, and failure to resume sinus rhythm following cardioversion. This syndrome can be congenital or acquired, particularly after surgical correction for heart defects.
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: Syndrome, Sick Sinus; Sick Sinus Node Syndrome; Sinus Node Dysfunction; Dysfunction, Sinus Node; Dysfunctions, Sinus Node; Sinus Node Disease; Sinus Node Diseases.
Where it fits in the MeSH classification
- Broader topics
- Arrhythmia, Sinus; Heart Block
Related concepts
- Sinoatrial Node
- Cardiac Sinus Arrest
- Sinoatrial Exit Block
- Bradycardia
- Atrial Fibrillation
- Cardioversion
Research landscape
PubMed indexes 2,962 records tagged with the MeSH heading “Sick Sinus Syndrome” (counts retrieved 2026-10-29). 334 of them (11.3%) were published from 2020 onward, and the busiest period so far is through 1999 with 1,503 records.
Reviews account for 245 records (8.3%) and meta-analyses for 9. Randomized controlled trials number 121 (4.1%) as a share of all records on the topic.
Show the data
| Period | Records |
|---|---|
| through 1999 | 1,503 |
| 2000-2009 | 513 |
| 2010-2019 | 612 |
| 2020 onward | 334 |
Publication-type chart data
| Type | Records | Share |
|---|---|---|
| Reviews | 245 | 8.3% |
| Meta-analyses | 9 | 0.3% |
| Randomized controlled trials | 121 | 4.1% |
Method: PubMed query "Sick Sinus Syndrome"[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.
Association of sick sinus syndrome with incident cardiovascular disease and mortality: the Atherosclerosis Risk in Communities study and Cardiovascular Health Study [1]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundSick sinus syndrome (SSS) is a common indication for pacemaker implantation.
- Closing excerpt
- The mechanisms underlying these associations warrant further investigation.
- 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 (239 words)
BackgroundSick sinus syndrome (SSS) is a common indication for pacemaker implantation. Limited information exists on the association of sick sinus syndrome (SSS) with mortality and cardiovascular disease (CVD) in the general population.MethodsWe studied 19,893 men and women age 45 and older in the Atherosclerosis Risk in Communities (ARIC) study and the Cardiovascular Health Study (CHS), two community-based cohorts, who were without a pacemaker or atrial fibrillation (AF) at baseline. Incident SSS cases were validated by review of medical charts. Incident CVD and mortality were ascertained using standardized protocols. Multivariable Cox models were used to estimate the association of incident SSS with selected outcomes.ResultsDuring a mean follow-up of 17 years, 213 incident SSS events were identified and validated (incidence, 0.6 events per 1,000 person-years). After adjustment for confounders, SSS incidence was associated with increased mortality (hazard ratio [HR] 1.39, 95% confidence interval [CI] 1.14-1.70), coronary heart disease (HR 1.72, 95%CI 1.11-2.66), heart failure (HR 2.87, 95%CI 2.17-3.80), stroke (HR 1.56, 95%CI 0.99-2.46), AF (HR 5.75, 95%CI 4.43-7.46), and pacemaker implantation (HR 53.7, 95%CI 42.9-67.2). After additional adjustment for other incident CVD during follow-up, SSS was no longer associated with increased mortality, coronary heart disease, or stroke, but remained associated with higher risk of heart failure (HR 2.00, 95%CI 1.51-2.66), AF (HR 4.25, 95%CI 3.28-5.51), and pacemaker implantation (HR 25.2, 95%CI 19.8-32.1).ConclusionIndividuals who develop SSS are at increased risk of death and CVD. The mechanisms underlying these associations warrant further investigation.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 25285853 · DOI · PMC4186847
The effect of unhealthy lifestyle on the pathogenesis of sick sinus syndrome: A life-guiding review [2]
Abstract reading summary — source excerpts
- Opening excerpt
- Sick sinus syndrome (SSS), also known as sinoatrial node dysfunction, has been widely concerned by the medical community.
- Closing excerpt
- This study also has guiding significance for the daily life of high-risk population of SSS and reducing the mortality of SSS patients.
- 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 (182 words)
Sick sinus syndrome (SSS), also known as sinoatrial node dysfunction, has been widely concerned by the medical community. The incidence rate of SSS is increasingly, which poses a great threat to public health. Through decades of repeated research in the medical field, great progress has been made in the pathogenesis of SSS and the interaction mechanism between SSS and other cardiovascular diseases. In this paper, we pay special attention to the mental stimulation factors under various pressures such as society and work, and the influence of smoking, drinking, and unhealthy diet on the pathogenesis of SSS. It also explains the mechanism of negative factors in the pathogenesis of SSS. These unhealthy lifestyle will lead to the occurrence of sinoatrial node disease and arrhythmia, and then induce SSS. Therefore, in the premise of increasing incidence rate of SSS and difficult to cure, how to avoid these harmful factors and ensure a healthy lifestyle is extremely important for preventing and treating SSS. This study also has guiding significance for the daily life of high-risk population of SSS and reducing the mortality of SSS patients.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 39470516 · DOI · PMC11521041
Disruption of mitochondria-sarcoplasmic reticulum microdomain connectomics contributes to sinus node dysfunction in heart failure [3]
Abstract reading summary — source excerpts
- Opening excerpt
- The sinoatrial node (SAN), the leading pacemaker region, generates electrical impulses that propagate throughout the heart.
- Closing excerpt
- The current study provides insights into the role of mitochondria-SR microdomains in SAN automaticity and possible therapeutic targets for SAN dysfunction in HF patients.
- 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 (240 words)
The sinoatrial node (SAN), the leading pacemaker region, generates electrical impulses that propagate throughout the heart. SAN dysfunction with bradyarrhythmia is well documented in heart failure (HF). However, the underlying mechanisms are not completely understood. Mitochondria are critical to cellular processes that determine the life or death of the cell. The release of Ca2+ from the ryanodine receptors 2 (RyR2) on the sarcoplasmic reticulum (SR) at mitochondria-SR microdomains serves as the critical communication to match energy production to meet metabolic demands. Therefore, we tested the hypothesis that alterations in the mitochondria-SR connectomics contribute to SAN dysfunction in HF. We took advantage of a mouse model of chronic pressure overload-induced HF by transverse aortic constriction (TAC) and a SAN-specific CRISPR-Cas9-mediated knockdown of mitofusin-2 (Mfn2), the mitochondria-SR tethering GTPase protein. TAC mice exhibited impaired cardiac function with HF, cardiac fibrosis, and profound SAN dysfunction. Ultrastructural imaging using electron microscope (EM) tomography revealed abnormal mitochondrial structure with increased mitochondria-SR distance. The expression of Mfn2 was significantly down-regulated and showed reduced colocalization with RyR2 in HF SAN cells. Indeed, SAN-specific Mfn2 knockdown led to alterations in the mitochondria-SR microdomains and SAN dysfunction. Finally, disruptions in the mitochondria-SR microdomains resulted in abnormal mitochondrial Ca2+ handling, alterations in localized protein kinase A (PKA) activity, and impaired mitochondrial function in HF SAN cells. The current study provides insights into the role of mitochondria-SR microdomains in SAN automaticity and possible therapeutic targets for SAN dysfunction in HF patients.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 36044551 · DOI · PMC9456763
Real-World Treatment of Patients With Sinus Node Dysfunction and Heart Failure With Preserved Ejection Fraction [4]
Abstract reading summary — source excerpts
- Opening excerpt
- BackgroundPermanent pacemaker (PPM) implantation is recommended in patients with sinus node dysfunction (SND).
- Closing excerpt
- Future work should focus on optimizing treatment pathways for patients with HFpEF and SND.
- 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 (181 words)
BackgroundPermanent pacemaker (PPM) implantation is recommended in patients with sinus node dysfunction (SND). In patients with coexisting heart failure with preserved ejection fraction (HFpEF), clinicians may be hesitant to treat SND due to concerns about exacerbating heart failure. Little is known about real-world PPM utilization and disease burden in the HFpEF population that has been assumed to benefit from low heart rates. This study aims to characterize the disease burden and PPM utilization in patients with SND+HFpEF versus SND-only in a Medicare population.MethodsPatients diagnosed with SND were identified in the Medicare administrative claims database and stratified by presence or abscence of prior evidence of HFpEF. Rates of the following clinical outcomes were compared between the cohorts during follow-up: PPM implant, HF hospitalization, atrial fibrillation (AF) hospitalization, second/third-degree AV block or HFrEF, myocardial infarction (MI), ischemic stroke, and all-cause mortality.ResultsSND+HFpEF (N = 26,986) patients were older (81.1 vs. 78.5, p ConclusionsPPM implant rates were lower, and overall disease burden was greater in HFpEF+SND patients compared to SND-only patients. Future work should focus on optimizing treatment pathways for patients with HFpEF and SND.
Abstract reproduced from the open-access article under the recorded cc by licence; © the authors. PMID 41755371 · DOI · PMC13456363
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 New insights into pacemaker activity: promoting understanding of sick sinus syndrome [5]
- Research article Sinus Node and Atrial Arrhythmias [6]
- Research article The natural history of sick sinus syndrome [7]
- Research article Cardiac sodium channel overlap syndromes: different faces of SCN5A mutations [8]
- Research article Deleterious effects of long-term single-chamber ventricular pacing in patients with sick sinus syndrome: the hidden benefits of dual-chamber pacing [9]
- Research article Diagnosis and treatment of sick sinus syndrome [10]
References
- Alonso A, Jensen PN, Lopez FL, Chen LY, Psaty BM, Folsom AR, et al.. Association of sick sinus syndrome with incident cardiovascular disease and mortality: the Atherosclerosis Risk in Communities study and Cardiovascular Health Study. . 2014. PMID 25285853 · DOI · PMC4186847
- Chang X, Zhang Q, Pu X, Liu J, Wang Y, Guan X, et al.. The effect of unhealthy lifestyle on the pathogenesis of sick sinus syndrome: A life-guiding review. . 2024. PMID 39470516 · DOI · PMC11521041
- Ren L, Gopireddy RR, Perkins G, Zhang H, Timofeyev V, Lyu Y, et al.. Disruption of mitochondria-sarcoplasmic reticulum microdomain connectomics contributes to sinus node dysfunction in heart failure. . 2022. PMID 36044551 · DOI · PMC9456763
- Habel N, Rosemas S, Higuera L, Zimmerman P, Meyer M. Real-World Treatment of Patients With Sinus Node Dysfunction and Heart Failure With Preserved Ejection Fraction. . 2026. PMID 41755371 · DOI · PMC13456363
- Dobrzynski H, Boyett MR, Anderson RH. New insights into pacemaker activity: promoting understanding of sick sinus syndrome. Circulation. 2007. PMID 17420362 · DOI
- John RM, Kumar S. Sinus Node and Atrial Arrhythmias. Circulation. 2016. PMID 27166347 · DOI
- Sutton R, Kenny RA. The natural history of sick sinus syndrome. Pacing Clin Electrophysiol. 1986. PMID 2432517 · DOI
- Remme CA, Wilde AA, Bezzina CR. Cardiac sodium channel overlap syndromes: different faces of SCN5A mutations. Trends Cardiovasc Med. 2008. PMID 18436145 · DOI
- Hesselson AB, Parsonnet V, Bernstein AD, Bonavita GJ. Deleterious effects of long-term single-chamber ventricular pacing in patients with sick sinus syndrome: the hidden benefits of dual-chamber pacing. J Am Coll Cardiol. 1992. PMID 1593051 · DOI
- Adán V, Crown LA. Diagnosis and treatment of sick sinus syndrome. Am Fam Physician. 2003. PMID 12725451
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.