The management of Brugada syndrome patients

Abstract

Brugada syndrome is a congenital electrical disorder characterised by the appearance of distinctive QRST-T patterns in the right precordial leads and an increased risk of sudden death (SCD) in young healthy adults. Although chamber enlargement is not apparent in most cases, autopsy and histological investigations have revealed structural abnormalities. The typical Brugada ECG manifestation is often concealed and may be revealed by Class IC anti-arrhythmic agents with the effect of blocking the fast component of sodium channel currents. The syndrome may also be unmasked or precipitated by a febrile state, vagotonic agents, α-adrenergic agonists, β-adrenergic blockers, tricyclic or tetracyclic antidepressants, a combination of glucose and insulin and hypokalaemia, as well as by alcohol and cocaine toxicity. Since the typical Brugada ECG pattern can be normalised by Class IA agents to block transient outward currents (I^to) or by isoproterenol and cilostazol to boost calcium channel currents, they have been considered pharmacological therapies aimed at rebalancing the ion channel currents during cardiac depolarisation and repolarisation. Case studies by intra-cardiac mappingguided ablation in the right ventricular outflow tract and Purkinje network have shown evidence of eliminating the substrate of ventricular tachycardia/fibrillation (VT/VF) in Brugada syndrome, which may be used as an adjunct to device therapy to abort electrical storms. At present the most effective therapy to prevent sudden cardiac death in Brugada syndrome is an implantable cardioverter defibrillator. (Cardiol J 2007; 14: 97–106)