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PubMed This is a summary of 23 peer-reviewed journal articles Updated
Cardiology

Brugada Syndrome vs. SUNDS: Are They the Same?

At a Glance

Yes, SUNDS and Brugada syndrome are the exact same genetic heart condition. SUNDS is simply the historical name for Brugada syndrome, primarily used in Southeast Asian populations. Both share the same SCN5A gene mutations, symptoms like nighttime gasping, and treatments like an ICD.

In this answer

3 sections

01

The History of SUNDS

02

How Genetic Testing Linked Them

03

Warning Signs and Management

Yes, Sudden Unexplained Nocturnal Death Syndrome (SUNDS) and Brugada syndrome are medically recognized as the exact same condition [1][2][3]. While they were originally thought to be different diseases, modern medicine now understands that SUNDS is the historical and cultural name for how Brugada syndrome affects certain populations, particularly those of Southeast Asian descent [1][3].

The History of SUNDS

For decades, researchers tracked a mysterious and tragic phenomenon where seemingly healthy adults—predominantly young men of Southeast Asian descent—were passing away suddenly in their sleep [4][1]. This condition became known clinically as Sudden Unexplained Nocturnal Death Syndrome (SUNDS). However, in the affected communities, it was often known by cultural names such as Bangungot in the Philippines, Lai Tai in Thailand, and Pokkuri in Japan [5][6]. Because the heart structurally appeared normal during autopsies, the cause of these nighttime events remained unknown for a long time.

Meanwhile, in 1992, researchers identified a heart rhythm disorder characterized by specific abnormal patterns on an electrocardiogram (ECG) and officially named it Brugada syndrome [7].

How Genetic Testing Linked Them

The breakthrough connecting SUNDS and Brugada syndrome came through modern genetic testing. Researchers discovered that both conditions share the same clinical presentation, ECG abnormalities, and genetic links [8][9].

The most well-established genetic link involves a gene called SCN5A [10][11]. This gene is responsible for creating a sodium channel, a tiny pore that allows sodium ions to flow in and out of heart muscle cells to generate normal electrical signals [12][13]. When this gene is mutated, the sodium channels do not function correctly, leading to chaotic electrical activity and potentially dangerous heart rhythms [12][14].

Because genetic tests found the exact same SCN5A mutations in Brugada syndrome patients and families historically affected by SUNDS, the medical community recognized them as the identical disease [8][10]. It is important to note, however, that an SCN5A mutation is currently identified in only about 30% of patients [15][16]. Many cases have no identifiable genetic mutation yet, highlighting that the genetics of this condition are complex and other factors may be involved [4][14].

Warning Signs and Management

Understanding that Brugada syndrome and SUNDS are the same condition is validating and crucial if you are researching your ancestry. If you have relatives who reportedly died of SUNDS, Bangungot, or Lai Tai, you should treat this as a family history of Brugada syndrome.

While the risk of sudden death sounds terrifying, highly effective, life-saving treatments exist. If you are diagnosed, your doctor will perform tests to determine your risk level. For those at high risk of dangerous heart rhythms, the primary treatment is an Implantable Cardioverter-Defibrillator (ICD) [17][18]. An ICD is a small device placed under the skin that constantly monitors your heart and automatically delivers a shock to restore a normal rhythm if a dangerous one occurs, effectively preventing sudden death [18][19].

Warning signs to watch out for include:

  • Syncope: Unexplained fainting, especially if it happens while resting or sleeping.
  • Nighttime gasping: Agonal breathing or sudden gasping/choking sounds during sleep.

Because the conditions are identical, the triggers are exactly the same. People with this condition must avoid:

  • High fevers: Fevers can worsen the electrical instability in the heart [20][21]. If you get a fever, take fever-reducing medication immediately (like acetaminophen) and go to the emergency room if it does not come down.
  • Electrolyte imbalances: Changes in potassium or sodium levels (such as hypokalemia, or low potassium) can be dangerous [20][22].
  • Certain medications: Many common prescription and over-the-counter drugs can further block sodium channels [23]. Always check your medications against the internationally recognized, gold-standard database at BrugadaDrugs.org before taking anything.

If you have a family history of SUNDS, it is highly recommended to consult a cardiologist or an electrophysiologist (a doctor who specializes in the heart’s electrical system) to discuss genetic testing, overnight monitoring, and preventative care.

Common questions in this guide

Are SUNDS and Brugada syndrome the same thing?
Yes, modern medicine recognizes Sudden Unexplained Nocturnal Death Syndrome (SUNDS) and Brugada syndrome as the exact same condition. SUNDS was the historical name for how the syndrome affected certain populations before the underlying electrical disorder was fully understood.
What is the genetic link between Brugada syndrome and SUNDS?
Both conditions share mutations in the SCN5A gene. This gene controls sodium channels in the heart, and when mutated, it leads to chaotic electrical activity and potentially dangerous heart rhythms.
What are the warning signs of Brugada syndrome or SUNDS?
Key warning signs include unexplained fainting, especially while resting, and sudden gasping or choking sounds during sleep. If you experience these symptoms or have a family history of them, it is important to consult a cardiologist.
How is Brugada syndrome treated?
For individuals at high risk of dangerous heart rhythms, the primary treatment is an Implantable Cardioverter-Defibrillator (ICD). This small device monitors the heart and automatically delivers a shock to restore a normal rhythm if a dangerous one occurs.
What triggers should I avoid if I have Brugada syndrome?
People with this condition must avoid high fevers, electrolyte imbalances like low potassium, and certain medications that block sodium channels. You should treat fevers immediately with medication and always check any new prescriptions against the BrugadaDrugs.org database.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Given my family history of SUNDS, should I undergo an overnight sleep study or a prolonged heart monitor test?
  2. 2.Should my children be genetically tested for an SCN5A mutation or undergo an ECG?
  3. 3.What specific protocol should I follow if I develop a high fever in the middle of the night?
  4. 4.How do we determine if I am at high enough risk to need an Implantable Cardioverter-Defibrillator (ICD)?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

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References

References (23)
  1. 1

    Update on the Diagnosis and Management of Brugada Syndrome.

    Vohra J, Rajagopalan S,

    Heart, lung & circulation 2015; (24(12)):1141-8.

    PMID: 26412486
  2. 2

    Genetic Analysis of Arrhythmogenic Diseases in the Era of NGS: The Complexity of Clinical Decision-Making in Brugada Syndrome.

    Allegue C, Coll M, Mates J, et al.

    PloS one 2015; (10(7)):e0133037 doi:10.1371/journal.pone.0133037.

    PMID: 26230511
  3. 3

    Critical Roles of Xirp Proteins in Cardiac Conduction and Their Rare Variants Identified in Sudden Unexplained Nocturnal Death Syndrome and Brugada Syndrome in Chinese Han Population.

    Huang L, Wu KH, Zhang L, et al.

    Journal of the American Heart Association 2018; (7(1)) doi:10.1161/JAHA.117.006320.

    PMID: 29306897
  4. 4

    Ethnic differences in patients with Brugada syndrome and arrhythmic events: New insights from Survey on Arrhythmic Events in Brugada Syndrome.

    Milman A, Andorin A, Postema PG, et al.

    Heart rhythm 2019; (16(10)):1468-1474 doi:10.1016/j.hrthm.2019.07.003.

    PMID: 31284050
  5. 5

    The biophysical characterization of the first SCN5A mutation R1512W identified in Chinese sudden unexplained nocturnal death syndrome.

    Zheng J, Zhou F, Su T, et al.

    Medicine 2016; (95(23)):e3836 doi:10.1097/MD.0000000000003836.

    PMID: 27281089
  6. 6

    Masquerading bundle branch block obscuring the diagnosis of Brugada syndrome: an electrocardiographic and vectorcardiographic study.

    Konopka IV, Garro HA, Tepper RB, et al.

    Clinical case reports 2017; (5(8)):1362-1368 doi:10.1002/ccr3.1059.

    PMID: 28781860
  7. 7

    J-Wave syndromes expert consensus conference report: Emerging concepts and gaps in knowledge.

    Antzelevitch C, Yan GX, Ackerman MJ, et al.

    Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology 2017; (19(4)):665-694 doi:10.1093/europace/euw235.

    PMID: 28431071
  8. 8

    Molecular Autopsy of Desmosomal Protein Plakophilin-2 in Sudden Unexplained Nocturnal Death Syndrome.

    Huang L, Tang S, Peng L, et al.

    Journal of forensic sciences 2016; (61(3)):687-91 doi:10.1111/1556-4029.13027.

    PMID: 27122407
  9. 9

    Identification of rare variants of DSP gene in sudden unexplained nocturnal death syndrome in the southern Chinese Han population.

    Zhao Q, Chen Y, Peng L, et al.

    International journal of legal medicine 2016; (130(2)):317-22 doi:10.1007/s00414-015-1275-2.

    PMID: 26585738
  10. 10

    Molecular pathological study on LRRC10 in sudden unexplained nocturnal death syndrome in the Chinese Han population.

    Huang L, Tang S, Chen Y, et al.

    International journal of legal medicine 2017; (131(3)):621-628 doi:10.1007/s00414-016-1516-z.

    PMID: 28032242
  11. 11

    Association of common and rare variants of SCN10A gene with sudden unexplained nocturnal death syndrome in Chinese Han population.

    Zhang L, Zhou F, Huang L, et al.

    International journal of legal medicine 2017; (131(1)):53-60 doi:10.1007/s00414-016-1397-1.

    PMID: 27272739
  12. 12

    Novel heterozygous mutation c.4282G>T in the SCN5A gene in a family with Brugada syndrome.

    Zhu JF, DU LL, Tian Y, et al.

    Experimental and therapeutic medicine 2015; (9(5)):1639-1645 doi:10.3892/etm.2015.2361.

    PMID: 26136871
  13. 13

    Reduced current density, partially rescued by mexiletine, and depolarizing shift in activation of SCN5A W374G channels as a cause of severe form of Brugada syndrome.

    Nakajima T, Dharmawan T, Kawabata-Iwakawa R, et al.

    Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc 2021; (26(3)):e12828 doi:10.1111/anec.12828.

    PMID: 33463855
  14. 14

    Update on Genetic Basis of Brugada Syndrome: Monogenic, Polygenic or Oligogenic?

    Campuzano O, Sarquella-Brugada G, Cesar S, et al.

    International journal of molecular sciences 2020; (21(19)) doi:10.3390/ijms21197155.

    PMID: 32998306
  15. 15

    Present Status of Brugada Syndrome: JACC State-of-the-Art Review.

    Brugada J, Campuzano O, Arbelo E, et al.

    Journal of the American College of Cardiology 2018; (72(9)):1046-1059 doi:10.1016/j.jacc.2018.06.037.

    PMID: 30139433
  16. 16

    Numerous Brugada syndrome-associated genetic variants have no effect on J-point elevation, syncope susceptibility, malignant cardiac arrhythmia, and all-cause mortality.

    Ghouse J, Have CT, Skov MW, et al.

    Genetics in medicine : official journal of the American College of Medical Genetics 2017; (19(5)):521-528 doi:10.1038/gim.2016.151.

    PMID: 27711072
  17. 17

    [Brugada syndrome--a rare cause of syncope and sudden death].

    Levin CG, Khalili P, Floderer E

    Lakartidningen 2015; (112()).

    PMID: 26660962
  18. 18

    Implantable cardioverter-defibrillator in Brugada syndrome: Long-term follow-up.

    El-Battrawy I, Roterberg G, Liebe V, et al.

    Clinical cardiology 2019; (42(10)):958-965 doi:10.1002/clc.23247.

    PMID: 31441080
  19. 19

    Quinidine-A legacy within the modern era of antiarrhythmic therapy.

    Vitali Serdoz L, Rittger H, Furlanello F, Bastian D

    Pharmacological research 2019; (144()):257-263 doi:10.1016/j.phrs.2019.04.028.

    PMID: 31026503
  20. 20

    Brugada syndrome: More than 20 years of scientific excitement.

    Brugada P

    Journal of cardiology 2016; (67(3)):215-20.

    PMID: 26627541
  21. 21

    [A man with fever-dependent ECG abnormalities].

    de Jong Y, Bilsen M, Grauss RW

    Nederlands tijdschrift voor geneeskunde 2019; (163()).

    PMID: 30816649
  22. 22

    Vinculin variant M94I identified in sudden unexplained nocturnal death syndrome decreases cardiac sodium current.

    Cheng J, Kyle JW, Wiedmeyer B, et al.

    Scientific reports 2017; (7()):42953 doi:10.1038/srep42953.

    PMID: 28218286
  23. 23

    Fever-Induced Brugada Syndrome Is More Common Than Previously Suspected: A Cross-Sectional Study from an Endemic Area.

    Rattanawong P, Vutthikraivit W, Charoensri A, et al.

    Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc 2016; (21(2)):136-41 doi:10.1111/anec.12288.

    PMID: 26178440

This page explains the medical connection between Brugada syndrome and SUNDS for educational purposes. Always consult a cardiologist or electrophysiologist regarding your specific family history or heart rhythm concerns.

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