Changes

Jump to navigation Jump to search

Brugada Syndrome

1,042 bytes added, 06:52, 1 August 2008
no edit summary
==Characteristics of the Brugada syndrome:==
*Inheritable arrhythmia syndrome with [[w:Autosomal_dominant|autosomal dominant]] inheritance. If one of both parents are affected, their children (either males or females) have a 50% chance of inheriting the disease.*Man Males are more often symptomatic than womenfemales, probably by the influence of sex hormones on cardiac arrhythmiasand/or ion channels, and a different distribution of ion channels across the heart in males versus females. *The arrhythmias usually occur between 30 and 40 years of age. (range 1-77 yrs) and often during rest or while sleeping(high vagal tone).*Only in about 30% of patients, genetic defects can be detected in the ([http://ghr.nlm.nih.gov/gene=scn5a SCN5A]) gengene which encodes the cardiac sodium channel. 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 other patients the disease is probably multi-genetic or caused by yet unknown genetic defects.*The right ventricular outflow tract (right before the pulmonary valve) ventricle is most affected in the Brugada syndrome, and particularly (but not specifically) the right ventricular outflow tract . *The prevalence varies between 5-50:10.000, largely depending on geographic location. In some south-east Asian countries the disease is considered endemic and sometimes considered believed to be the second cause of death amongst young men (after car accidents). There it In these countries Brugada syndrome is called 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 the syndromeSUDS: in the Phillipines it is called ''bangungut'' (to rise and moan in sleep) and in Thailand ''lai tai'' (death during sleep).
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>
==Diagnosis and treatment==
*Patients who are symptomatic (unexplained syncope, ventricular tachycardias or survivors of sudden cardiac death) have a mortality risk of up to 10% per year. In these patients an [[:w:nl:Internal_Cardiac_Defibrillator|ICD]] should be implanted. *Some groups advice an electrofysiologic electrophysiological investigation (inducibility of VF) for risk assessment in Brugada patients,<cite>brug2</cite><cite>brug3</cite> but others could not reproduce the predicive value of these tests,<cite>priori</cite><cite>eckhardt</cite> so this the value of inducibility is still (very) controversial.*In large studies familiar familial sudden death is did not appear to be a risk factor for sudden death in siblings.*In asymptomatic patients in whom the Brugada ECG characteristics are present (either spontaneously or provoked by fever or sodium channel blockers (like ajmaline, procainimde or flecainide) life style advices are given, which include:**A number of medications should not be taken (amongst others which beta-blockers, and sodium channel blockers such as certain anti-depressants and anti-arrhythmics)**Rigorous treatment of fever with paracetamol / Tylenol, as fever may elicited the Brugada ECG and arrhythmias in some patients
For a full list of the diagnostic criteria, see <cite>Wilde</cite>
Three ECG repolarization patterns in the right precordial leads are recognized in the diagnosis of Brugada syndrome.
'''Type I''' is the only ECG criterium criterion that is diagnostic of Brugada syndrome. Type The type I repolarization ECG is characterized by a coved ST-segment J elevation >=2 mm (0.2 mV) followed by a negative T wave (see figure). Brugada syndrome is definitively diagnosed when a type 1 ST-segment elevation is observed in >1 right precordial lead (V1 to V3) in the presence or absence of a sodium channel–blocking agent, and in conjunction with one of the following:
*documented ventricular fibrillation (VF)
*polymorphic ventricular tachycardia (VT)
*syncope
*nocturnal agonal respiration.
The sensitivity of the ECG for Brugada syndrome can be increased with placement of ECG leads in the intercostal space above V1 and V2 (V1ic3 and V2ic3)
Electrocardiograms of Brugada patients can change over time from type I to type II and/or normal ECGs and back.A type III ECG is rather common and is concidered considered a normal variant, but also the Type II is a normal variant(albeit suggestive of Brugada syndrome).
{| class="wikitable" font-size="90%"

Navigation menu