Brugada Syndrome: Difference between revisions

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''Louise R.A. Olde Nordkamp, Arthur A.M. Wilde''
''By: Louise R.A. Olde Nordkamp, Arthur A.M. Wilde''


[[Image:Brugada.png|thumb|right|Typical ECG abnormalities in Brugada syndrome: ST elevation in V1-V3, without ischemia.<cite>Wilde</cite>]]
[[Image:Brugada.png|thumb|right|Typical ECG abnormalities in Brugada syndrome: ST elevation in V1-V3, without ischemia.<cite>Wilde</cite>]]
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*The arrhythmias typically occur in patients between 30-40 years of age and often during rest or while sleeping.
*The arrhythmias typically occur in patients between 30-40 years of age and often during rest or while sleeping.
*The right ventricle is most affected in Brugada syndrome, and particularly (but not specifically) the right ventricular outflow tract.
*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 prevalence varies between 5-50:10.000, largely depending on the geographic location (especially in some Southeast Asian countries the disease is more prevalent).  


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==ECG tests==
==ECG tests==
[[File:PlaatjesBrS_graphs.svg|thumb|right|400px]]
[[File:PlaatjesBrS_graphs.svg|thumb|right|400px|<cite>Brugada2</cite>]]
The ECG in Brugada syndrome is characterized by ST-segment elevations directly followed by a negative T-wave in the right precordial leads (V1-V3) and in leads positioned one or two intercostal space higher. It is referred to as a coved type Brugada ECG, or type 1 ECG, and cannot be explained by electrolyte disturbances, ischemia or structural heart disease. This specific ECG hallmark typically fluctuates over time, and can also be presented as a type 2 or type 3 ECG or even a normal ECG. The type 2 ST-segment elevation has a saddleback appearance with a high takeoff ST-segment elevation of ≥ 2mm, a trough displaying ≥1mm, and then either a positive or a biphasic T wave. Type 3 has either a saddleback or coved appearance with a ST-segment elevation of <1mm (figure 1). Type 2 and 3 are not diagnostic of the BrS. In some patients a type 1 ECG may only be unmasked or modulated by sodium channel blockers (such as ajmaline or flecainide) a febrile state, vagotonic agents, α-adrenergic agonists, β-adrenergic blockers, tricyclic or tetracyclic antidepressants, a combination of glucose and insulin, hyperkalemia, hypokalemia, hypercalcemia, and alcohol or cocaine toxicity.
The ECG in Brugada syndrome is characterized by ST-segment elevations directly followed by a negative T-wave in the right precordial leads (V1-V3) and in leads positioned one or two intercostal space higher. It is referred to as a coved type Brugada ECG, or type 1 ECG, and cannot be explained by electrolyte disturbances, ischemia or structural heart disease. This specific ECG hallmark typically fluctuates over time, and can also be presented as a type 2 or type 3 ECG or even a normal ECG. The type 2 ST-segment elevation has a saddleback appearance with a high takeoff ST-segment elevation of ≥ 2mm, a trough displaying ≥1mm, and then either a positive or a biphasic T wave. Type 3 has either a saddleback or coved appearance with a ST-segment elevation of <1mm (figure 1). Type 2 and 3 are not diagnostic of the BrS. In some patients a type 1 ECG may only be unmasked or modulated by sodium channel blockers (such as ajmaline or flecainide) a febrile state, vagotonic agents, α-adrenergic agonists, β-adrenergic blockers, tricyclic or tetracyclic antidepressants, a combination of glucose and insulin, hyperkalemia, hypokalemia, hypercalcemia, and alcohol or cocaine toxicity.
[[Image:Brugada_syndrome_type1_example2.png|thumb|300px|An example of a Brugada type I ECG]]
[[Image:Brugada_syndrome_type1_example2.png|thumb|300px|An example of a Brugada type I ECG]]
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==Risk Stratification==  
==Risk Stratification==  
[[File:PlaatjesBrS_pyramid.svg|thumb|right|400px]]
[[File:PlaatjesBrS_pyramid.svg|thumb|right|400px|Risk stratification scheme according to clinical variables in Brugada syndrome
<cite>priori</cite>]]
Brugada syndrome patients with symptoms (a history of VT/VF or cardiac syncope) and spontaneous coved-type ECG are at risk for future arrhythmic events. However, risk stratification<cite>strat</cite> in asymptomatic Brugada syndrome patients is still ill-defined. Family history of sudden cardiac death, male gender and inducibility of VT/VF during programmed electrical stimulation<cite>PRELUDE</cite> is not consistently shown to be a risk factor. Therefore, risk stratification is best done by an expert cardio-genetics cardiologist.<cite>priori</cite>
Brugada syndrome patients with symptoms (a history of VT/VF or cardiac syncope) and spontaneous coved-type ECG are at risk for future arrhythmic events. However, risk stratification<cite>strat</cite> in asymptomatic Brugada syndrome patients is still ill-defined. Family history of sudden cardiac death, male gender and inducibility of VT/VF during programmed electrical stimulation<cite>PRELUDE</cite> is not consistently shown to be a risk factor. Therefore, risk stratification is best done by an expert cardio-genetics cardiologist.<cite>priori</cite>