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Brugada Syndrome: Difference between revisions
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(Created page with "thumb|Typical ECG abnormalities in Brugada syndrome: ST elevation in V1-V3, without ischemia. [[Image:Brugada_ecg_characteristics.png|thumb| Typical ECG abn...") |
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[[Image:Brugada.png|thumb|Typical ECG abnormalities in Brugada syndrome: ST elevation in V1-V3, without ischemia.]] | [[Image:Brugada.png|thumb|right|Typical ECG abnormalities in Brugada syndrome: ST elevation in V1-V3, without ischemia.]] | ||
[[Image:Brugada_ecg_characteristics.png|thumb| Typical ECG abnormalities in Brugada syndrome]] | [[Image:Brugada_ecg_characteristics.png|thumb|right|Typical ECG abnormalities in Brugada syndrome]] | ||
[[Image:brugada.jpg|thumb| Dr. Pedro Brugada. Pedro and Josep Brugada described in 1992 a landmark publication with a case-series of 8 patients with sudden cardiac death. <cite>Brugada</cite> Currently, three brothers of the Brugada family (Pedro, Josep and Ramon Brugada) conduct research in the syndrome that has been named after them.]] | [[Image:brugada.jpg|thumb|right|Dr. Pedro Brugada. Pedro and Josep Brugada described in 1992 a landmark publication with a case-series of 8 patients with sudden cardiac death. <cite>Brugada</cite> Currently, three brothers of the Brugada family (Pedro, Josep and Ramon Brugada) conduct research in the syndrome that has been named after them.]] | ||
[[Image:scn5a.jpg|thumb| 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)'''. | 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)'''. | ||
==Characteristics of the Brugada syndrome:== | ==Characteristics of the Brugada syndrome:== | ||
*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. | *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. | ||
*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. | *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. | ||
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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> | 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== | |||
{| class="wikitable" border="0" cellpadding="0" cellspacing="0" width="800px" | |||
|- | |||
!colspan="6"|Table 2: Here is a list of the Genes linked to the Brugada syndrome. | |||
|- align=center | |||
|'''Type''' | |||
|'''OMIM''' | |||
|'''Gene''' | |||
|'''Protein''' | |||
|'''Functional role in cardiomyocytes''' | |||
|'''Effect of mutation''' | |||
|- | |||
!colspan="6"|Autosomal dominant inheritance | |||
|- | |||
|BrS1 | |||
|#601144 | |||
|SCN5A | |||
|Na<sub>v</sub>1.5 | |||
|α subunit of I<sub>Na</sub> channel | |||
|Loss of function of I<sub>Na</sub> | |||
|- | |||
|BrS2 | |||
|#611777 | |||
|GPD1-L | |||
|G3PD1L | |||
|Not fully established | |||
|Loss of function of I<sub>Na</sub> | |||
|- | |||
|BrS3 | |||
|#611875 | |||
|CACNA1C | |||
|Ca<sub>v</sub>1.2 | |||
|α<sub>1C</sub> subunit of I<sub>Ca,L channel</sub> | |||
|Loss of function of I<sub>Ca,L</sub> | |||
|- | |||
|BrS4 | |||
|#611876 | |||
|CACNB2b | |||
|Ca<sub>v</sub>β2b | |||
|β2b subunit of I<sub>Ca,L</sub> channel | |||
| | |||
|- | |||
|BrS5 | |||
|#612838 | |||
|SCN1B | |||
|Na<sub>v</sub>β1 | |||
|β subunit of I<sub>Na</sub> channel | |||
|Loss of function of I<sub>Na</sub> | |||
|- | |||
|BrS6 | |||
|#613119 | |||
|KCNE3 | |||
|KCNE3 (MiRP2) | |||
|β subunit of voltage-dependent K<sup>+</sup> channels | |||
|Gain of function of I<sub>to</sub> | |||
|- | |||
|BrS7 | |||
|#613120 | |||
|SCN3B | |||
|Na<sub>v</sub>β 3 | |||
|β subunit of I<sub>Na</sub> channel | |||
|Loss of function of I<sub>to</sub> | |||
|- | |||
|NC | |||
|#613123 | |||
|HCN4 | |||
|HCN4 | |||
|α subunit of I<sub>f</sub> | |||
|Gain of function of I<sub>f</sub> | |||
|- | |||
|NC | |||
| | |||
|CACNA2D1 | |||
|Ca<sub>v</sub>α<sub>2</sub> δ-1 | |||
|</sub>α<sub>2</sub> δ subunit of I<sub>Ca,L</sub> channel | |||
|Loss of function of I<sub>Ca,L</sub> | |||
|- | |||
|NC | |||
| | |||
|MOG1 | |||
|MOG1 | |||
|Regulates tra?cking of Na<sub>v</sub>1.5 to the membrance | |||
|Loss of function of I<sub>Na</sub> | |||
|- | |||
|NC | |||
| | |||
|KCND3 | |||
|K<sub>v</sub>4.3 | |||
|α subunit of I<sub>to</sub> channel | |||
|Gain of function of I<sub>to</sub> | |||
|- | |||
|NC | |||
| | |||
|KCNE1L (KCNE5) | |||
|KCNE1L | |||
|β subunit of voltage-dependent K<sub>+</sub> channels | |||
|Gain of function of I<sub>to</sub> | |||
|- | |||
|NC | |||
| | |||
|KCNJ8 | |||
|K<sub>ir</sub>6.1 | |||
|α subunit of I<sub>K,ATP</sub> | |||
|Gain of function of I<sub>K,ATP</sub> | |||
|- | |||
|NC | |||
| | |||
|SCN1B''b'' | |||
|Na<sub>v</sub>β1B | |||
|β subunit of I<sub>Na</sub> | |||
|Loss of function of I<sub>Na</sub> and gain of function of I<sub>to</sub> | |||
|- | |||
|colspan="6" bgcolor="#99CCFF"|OMIM: Online Mendelian Inheritance in Man compendium of human genes and genetic phenotypes; BrS1–BrS7: Brugada syndrome types 1–7; NC: no | |||
consensus; I<sub>Ca,L</sub>: L-type calcium current; I<sub>f</sub>: hyperpolarization-activated current; I<sub>K,ATP</sub>: ATP-sensitive potassium current; I<sub>Na</sub>: fast sodium current; I<sub>to</sub>: transient outward potassium current. | |||
|} | |||
==Diagnosis and treatment== | ==Diagnosis and treatment== | ||
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==Electrocardiographic criteria== | ==Electrocardiographic criteria== | ||
[[Image:Brugada_lead_placement.png|thumb|Changed lead positions of leads V3 and V5 to increase the sensitiviy to 'catch' a Brugada pattern on the ECG]] | [[Image:Brugada_lead_placement.png|thumb|right|Changed lead positions of leads V3 and V5 to increase the sensitiviy to 'catch' a Brugada pattern on the ECG]] | ||
Three ECG repolarization patterns in the right precordial leads are recognized in the diagnosis of Brugada syndrome. | Three ECG repolarization patterns in the right precordial leads are recognized in the diagnosis of Brugada syndrome. | ||