Brugada Syndrome: Difference between revisions

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[[Image:scn5a.jpg|thumb|right|The SCN5a gen is located on the short arm (p) of chromosome 3]]
[[Image:scn5a.jpg|thumb|right|The SCN5a gen is located on the short arm (p) of chromosome 3]]


The '''Brugada syndrome is an hereditary disease that is associated with high risk of sudden cardiac death'''. It is characterized by typical ECG abnormalities: '''ST segment elevation in the precordial leads (V1 - V3)'''.
'''Brugada syndrome''' refers to a hereditary disease that is associated with a risk of sudden cardiac death. It is characterized by typical ECG abnormalities: ST segment elevation in the precordial leads (V1 - V3).


==Characteristics of the Brugada syndrome:==
The Brugada brothers were the first to describe the characteristic ECG findings and link them to sudden death. Before that, the characteristic ECG findings, were often mistaken for a right ventricle myocardial infarction and already in 1953, a publication mentions that the ECG findings were not associated with ischemia as people often expected.


*Inheritable arrhythmia syndrome with [[w:Autosomal_dominant|autosomal dominant]] inheritance. If one of the two parents is affected, each child (both males and females) has a 50% chance of inheriting the disease.
==General features==
*Males are more often symptomatic than females, probably by the influence of sex hormones on cardiac arrhythmias and/or ion channels, and a different distribution of ion channels across the heart in males versus females.
*The diagnosis is based on ECG findings.
*The arrhythmias usually occur in patients between 30 and 40 years of age. (range 1-77 yrs) and often during rest or while sleeping (high vagal tone).
*It is an inheritable cardiac arrhythmia syndrome with an autosomal dominant inheritance.
*In only about 30% of patients, genetic defects can be detected in the ([http://ghr.nlm.nih.gov/gene=scn5a SCN5A]) gene which encodes the cardiac sodium channel (loss-of-function mutation). In much smaller quantities, mutations may be found in the GPD1L gene (which probably influences cardiac sodium channel function) or in cardiac calcium channel encoding genes (CACNxxx). In the remaining patients, the disease is probably multi-genetic or caused by yet unknown genetic defects.
*Males are often more symptomatic than females, probably by the influence of sex hormones on cardiac arrhythmias and/or ion channels.
*The right ventricle is most affected in Brugada syndrome, and particularly (but not specifically) the right ventricular outflow tract .  
*The arrhythmias typically occur in patients between 30-40 years of age and often during rest or while sleeping.
*The prevalence varies between 5-50:10.000, largely depending on geographic location. In some southeast Asian countries the disease is considered endemic and believed to be the second cause of death among young men (after car accidents). In these countries Brugada syndrome is believed to underly (in part) the 'Sudden Unexpected Death Syndrome' (SUDS). This relation has, however, not been thoroughly investigated and there are almost no epidemiological studies into Brugada syndrome ECGs (apart from Japan). In different Asian countries, different names have been given to SUDS: in the Phillipines it is called ''bangungut'' (to rise and moan in sleep) and in Thailand ''lai tai'' (death during sleep).  
*The right ventricle is most affected in Brugada syndrome, and particularly (but not specifically) the right ventricular outflow tract.
*The prevalence varies between 5-50:10.000, largely depending on the geographic location (especially in some Southeast Asian countries the disease is more prevalent).  


The Brugada brothers were the first to describe the characteristic ECG findings and link them to sudden death. Before that, the characteristic ECG findings, were often mistaken for a [[Right_Ventricle_MI|right ventricle myocardial infarction]] and already in 1953, a publication mentions that the ECG findings were not associated with ischemia as people often expected.<cite>osher</cite>


==Genes linked to the Brugada Syndrome==
==Clinical diagnosis==
The clinical diagnosis of Brugada syndrome is confirmed in an individual with the following:
 
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