Brugada syndrome: Clinical and genetic aspects

Abstract

Brugada Syndrome is characterized by a speci fic ECG pattern with ST segment elevation in the right precordial leads and is associated with a high risk of sudden cardiac death (SCD) at young age particularly in situations with an augmented vagal tone. SCD occurs due to ventricular tachycardia (VT)/fibrillation (VF). One of the most striking elements of this inherited syndrome is that no gross structural cardiac abnormalities are found in affected patients. Moreover, the penetrance of the disease is very variable, therefore only a minority of the affected patients will develop symptomatic arrhythmias. Not only the diagnosis, but especially the prompt identi fication of the patients at risk has become a real challenge for the cardiologists. Although Brugada syndrome is quite rare, the worldwide interest around its pathophysiologic mechanism, risk strati fication strategies and treatment is outstanding, as witnessed by the many publications in a relative short span of time. As with other primary arrhythmias syndromes, the most fascinating aspect for the researchers is to be able to unravel the genetic background and to provide functional data of the mutant cardiac channel on conduction and repolarisation parameters. Cardiac susceptibility to develop arrhythmias will derive from these effects in combination with other factors, like the gender of the patient, the body temperature or the concomitant use of drugs. In the majority of the cases the cardiac voltage gated sodium channel is involved, still the genetic yield of the Brugada syndrome is low and more recent data focus the attention on other cardiac channels like the calcium channels. In both cases the clinical phenotype can display features of multiple arrhythmias syndrome among which the Long QT and the Lev-Lenègre syndromes in combinations with typical features of Brugada syndrome.