Sudden unexpected death syndrome

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Not to be confused with Sudden cardiac death.
Classification and external resources
ICD-10 R96.0

Sudden unexpected death syndrome (SUDS), sudden unexpected nocturnal death syndrome (SUNDS), sudden adult death syndrome (SADS), or bed death is sudden unexpected death of adolescents and adults, many during sleep.[1][2] Sudden unexplained death syndrome was first noted in 1977 among Hmong refugees in the US.[3][4] The disease was again noted in Singapore, when a retrospective survey of records showed that 230 otherwise healthy Thai men died suddenly of unexplained causes between 1982 and 1990:[5] In the Philippines, where it is referred to in the vernacular as bangungot, SUNDS affects 43 per 100,000 per year among young Filipinos. Most of the victims are young males.[6]


In about 1 in every 20 cases of sudden cardiac death, no definite cause of death can be found, even after the heart has been examined by an expert cardiac pathologist. This is then called Sudden Arrhythmic Death Syndrome. In the past it has also been called Sudden Adult Death Syndrome or Sudden Death Syndrome but, because it affects children too, the term Sudden Arrhythmic Death Syndrome is now used. It is thought that cot death (Sudden Infant Death Syndrome, or SIDS) may be partly due to the same causes responsible for SADS.[7]

A sudden death in a young person can be caused by heart disease (including cardiomyopathy, congenital heart disease, myocarditis, genetic connective tissue disorders, mitral valve prolapse or conduction disease), medication-related causes or other causes.[8]

Research suggests that sudden death may be caused infrequently by conditions such as fits (epilepsy) and severe asthma attacks. Pulmonary embolus (a clot to the lungs) has become better known recently due to its association with staying immobile for long periods during air travel. It can cause a sudden collapse and a rapid death.[9]

The conditions responsible for SADS cause a cardiac arrest by bringing on a 'ventricular arrhythmia' (a disturbance in the heart's rhythm), even though the person has no structural heart disease. There is a group of relatively rare diseases called ion channelopathies that affect the electrical functioning of the heart without affecting the heart's structure. This means that they can only be detected in life and not at post-mortem. Ion channelopathies are probably responsible for 4 in every 10 cases of SADS. There are several different types of ion channelopathies including, long QT syndrome (LQTS), Brugada syndrome CPVT (catecholaminergic polymorphic ventricular tachycardia), PCCD (progressive cardiac conduction defect), Early repolarisation syndrome, Mixed sodium channel disease and Short QT syndrome. [10]

In most of the inherited conditions known to cause SADS, mutations of specific genes have been detected and are thought to cause a specific disease. More research is required in this area. As research progresses, more genes will be identified and there will be better tools to decide whether the impact of a mutation causes a disease. [11]

In some cultures, SUNDS has been cloaked in superstition. Many Filipinos believe ingesting high levels of carbohydrates just before sleeping causes bangungot. It has only been recently that the scientific world has begun to understand this syndrome. Victims of bangungot have not been found to have any organic heart diseases or structural heart problems.[citation needed] However, cardiac activity during SUNDS episodes indicates irregular heart rhythms and ventricular fibrillation. The victim survives this episode if the heart's rhythm goes back to normal. Older Filipinos recommend wiggling the big toe of people experiencing this to encourage their heart to snap back to normal.[12]

In the Philippines, most cases of "bangungot" have been linked with acute hemorrhagic pancreatitis by Filipino medical personnel although the effect might have been due to changes in the pancreas during post-mortem autolysis.[13] In Thailand and Laos, bangungot (or in their term, sudden adult death syndrome) is caused by the Brugada syndrome.[14]


The condition appears to affect primarily young Hmong men from Laos (median age 33)[15] and northeastern Thailand (where the population are mainly of Laotian descent).[16][17]


The only proven way to prevent death is by implantation of a cardiovertor defibrillator. Oral antiarrhythmics such as propranolol are ineffective.[18]

Folk beliefs[edit]

This phenomenon is well known among the Hmong people of Laos,[19] who ascribe these deaths to a malign spirit, dab tsuam (pronounced "da cho"), said to take the form of a jealous woman. Hmong men may even go to sleep dressed as women so as to avoid the attentions of this spirit.[citation needed]

Hmong people believed that rejecting the role of becoming a shaman, they are taken into the spirit world.

Bangungot is depicted in the Philippines as a mythological creature called batibat or bangungot. This hag-like creature sits on the victim's face or chest so as to immobilize and suffocate him. When this occurs, the victim usually experiences paralysis. It's said that one should bite their tongue and wiggle their toes to try to get out of this paralysis or they may die from suffocation.


Name variations in English[edit]

Name Acronym Notes
sudden unexpected death syndrome SUDS
sudden unexplained death syndrome SUDS
sudden unexpected nocturnal death syndrome SUNDS
sudden unexplained nocturnal death syndrome SUNDS
sudden adult death syndrome SADS (parallel in form with SIDS)
sudden arrhythmia death syndrome SADS
sudden arrhythmic death syndrome SADS
sudden arrhythmic cardiac death syndrome
bed death

Names in different languages[edit]

Term Language Notes
bangungot or uom Filipino[20] The term originated from the Tagalog word meaning "to rise and moan in sleep".[13] It is also the Tagalog word for nightmare.
dab tsog Laotian[19]
lai tai Thai (Thai: ใหลตาย; meaning "sleep and die")[16][21]
dolyeonsa Korean
pokkuri disease Japanese[22]
ya thoom Arabic
albarsty (Kyrgyz: албарсты) Kyrgyz

See also[edit]


  1. ^ "Documentary maker died of sudden adult death syndrome, coroner rules" by Caroline Davies, The Guardian, December 12, 2013, Retrieved 2013-12-31
  2. ^ Also known as SUDS. See: Reddy PR, Reinier K, Singh T, Mariani R, Gunson K, Jui J, Chugh SS. Physical activity as a trigger of sudden cardiac arrest: The Oregon Sudden Unexpected Death Study. Int J Cardiol. 2008
  3. ^ Centers for Disease Control (CDC) (1981). "Sudden, unexpected, nocturnal deaths among Southeast Asian refugees". MMWR. Morbidity and mortality weekly report 30 (47): 581–589. PMID 6796814. 
  4. ^ Parrish RG, Tucker M, Ing R, Encarnacion C, Eberhardt M (1987). "Sudden unexplained death syndrome in Southeast Asian refugees: a review of CDC surveillance". MMWR CDC Surveil Summ 36 (1): 43SS–53SS. PMID 3110586. 
  5. ^ Goh KT, Chao TC, Chew CH (1990). "Sudden nocturnal deaths among Thai construction workers in Singapore". Lancet 335 (8698): 1154. doi:10.1016/0140-6736(90)91153-2. PMID 1971883. 
  6. ^ Gervacio-Domingo, G.; F . Punzalan; M . Amarillo; A . Dans. "Sudden unexplained death during sleep occurred commonly in the general population in the Philippines: a sub study of the National Nutrition and Health Survey .". Journal of Clinical Epidemiology 60 (6): 561–571. Retrieved 2008-12-09. 
  7. ^
  8. ^
  9. ^
  10. ^
  11. ^
  12. ^ Ramos, Maximo D. (1971). Creatures of Philippine Lower Mythology. Philippines: University of the Philippines Press. 
  13. ^ a b . Munger, Ronald G.; Booton, Elizabeth A. (1998). "Bangungut in Manila: sudden and unexplained death in sleep of adult Filipinos" (PDF). International Journal of Epidemiology 27 (4): 677–684. doi:10.1093/ije/27.4.677. PMID 9758125. Retrieved 2011-07-29. [dead link]
  14. ^ (link broken as of 3 October 2007).
  15. ^ Munger RG (1987). "Sudden death in sleep of Laotian-Hmong refugees in Thailand: a case-control study". Am J Public Health 77 (9): 1187–90. doi:10.2105/AJPH.77.9.1187. 
  16. ^ a b Tatsanavivat P, Chiravatkul A, Klungboonkrong V, Chaisiri S, Jarerntanyaruk L, Munger RG, Saowakontha S (1992). "Sudden and unexplained deaths in sleep (Laitai) of young men in rural northeastern Thailand". Int J Epidemiol 21 (5): 904–10. doi:10.1093/ije/21.5.904. PMID 1468851. 
  17. ^ Tungsanga K, Sriboonlue P (1993). "Sudden unexplained death syndrome in north-east Thailand". Int J Epidemiol 22 (1): 81–7. doi:10.1093/ije/22.1.81. PMID 8449651. 
  18. ^ Nademanee K, Veerakul G, Mower M, et al. (2003). "Defibrillator Versus beta-Blockers for Unexplained Death in Thailand (DEBUT): a randomized clinical trial". Circulation 107 (17): 2221–6. doi:10.1161/01.CIR.0000066319.56234.C8. PMID 12695290. 
  19. ^ a b Adler SR (1995). "Refugee stress and folk belief: Hmong sudden deaths". Soc Sci Med 40 (12): 1623–9. doi:10.1016/0277-9536(94)00347-V. PMID 7660175. 
  20. ^ Munger RG, Booton EA (1998). "Bangungut in Manila: sudden and unexplained death in sleep of adult Filipinos". Int J Epidemiol 27 (4): 677–84. doi:10.1093/ije/27.4.677. PMID 9758125. 
  21. ^ Himmunngan P, Sangwatanaroj S, Petmitr S, Viroonudomphol D, Siriyong P, Patmasiriwat P (March 2006). "HLa-class II (DRB & DQB1) in Thai sudden unexplained death syndrome (Thai SUDS) families (Lai-Tai families)". Southeast Asian J. Trop. Med. Public Health 37 (2): 357–65. PMID 17124999. 
  22. ^ Gotoh K (1976). "A histopathological study on the conduction system of the so-called "Pokkuri disease" (sudden unexpected cardiac death of unknown origin in Japan". Jpn Circ J 40 (7): 753–68. doi:10.1253/jcj.40.753. PMID 966364. 

Further reading[edit]