[Brugada syndrome, a rare cause of syncope].
BACKGROUND
The Brugada syndrome is an autosomal dominant disorder characterized by life-threatening ventricular tachyarrhythmias due to cardiac conductance disturbance without structural heart disease. Mutations of the SCN5A gene cause either a reduction in cardiac Na(+) channel expression or alterations in channel-gating properties, leading to a reduction in Na(+) current amplitude.


METHODS
A 37-year-old patient presented after a syncopal spell preceded by dizziness. 6 years ago he had experienced similar symptoms. At that time, physical and clinical examination did not lead to a convincing diagnosis. The initial ECG showed typical signs of the Brugada syndrome with descending ST elevation in leads V(1) and V(2). The ECG changes could be observed over the next 3 days. Thereafter, ECG changes reversed to normal. Ultrasound examination did not show any signs of structural heart disease. During electrophysiological testing no sustained ventricular tachyarrhythmias were inducible. Molecular genetic analysis in this young patient revealed a mutation in the SCN5A gene. According to the patient's symptoms, an automatic cardioverter defibrillator (ICD) was implanted.


CONCLUSIONS
A history of unexplained syncope in patients with a structurally normal heart should raise the suspicion of malignant arrythmias caused by primary arrythmogenic disorders. The diagnosis of Brugada syndrome can be concluded from typical ECG changes (i. e., incomplete right bundle branch block, ST elevation in leads V(1)-V(3)) accompanied by typical symptoms and a positive family history. To date, there is no effective therapy of the gene defect or its pathophysiological correlate available. Therefore, ICD therapy is recommended in symptomatic patients to prevent sudden cardiac death.
Auerbach
Holger
H
Medizinische Klinik, GPR-Klinikum Rüsselsheim, Akademisches Lehrkrankenhaus der Universität, Mainz. Auerbach@gp-ruesselsheim.de
Blank
Ralf
R
Jank
Katharina
K
Grönefeld
Gerian
G
Klingenheben
Thomas
T
Marschall
Christoph
C
von Mengden
Hans-Jürgen
HJ
D000328:Adult; D002869:Chromosome Aberrations; D004252:DNA Mutational Analysis; D016757:Death, Sudden, Cardiac / Q000517:prevention & control; D017147:Defibrillators, Implantable; D003937:Diagnosis, Differential; D005799:Genes, Dominant; D006801:Humans; D008297:Male; D009124:Muscle Proteins / Q000235:genetics; D062554:NAV1.5 Voltage-Gated Sodium Channel; D015222:Sodium Channels / Q000235:genetics; D013575:Syncope / Q000209:etiology* / Q000517:prevention & control; D013577:Syndrome; D017180:Tachycardia, Ventricular / Q000150:complications* / Q000235:genetics / Q000628:therapy
D009124:Muscle Proteins; D062554:NAV1.5 Voltage-Gated Sodium Channel; C568320:SCN5A protein, human; D015222:Sodium Channels