Factors That Modulate ECG and Arrhythmic Manifestations of the Brugada Syndrome

ST segment elevation in the Brugada syndrome is often dynamic. The Brugada ECG is often concealed and can be unmasked or modulated by sodium channel blockers, a febrile state, vagotonic agents, a-adrenergic agonists, -adrenergic blockers, tricyclic or tetracyclic antidepressants, a combination of glucose and insulin, hyperkalemia, hypokalemia, hypercalcemia, and by alcohol and cocaine toxicity (Brugada et al. 2000bc Miyazaki et al. 1996 Babaliaros and Hurst 2002 Goldgran-Toledano et al. 2002...

Cellular and Ionic Basis

The ability of the RV action potential to lose its dome, giving rise to phase 2 reentry and other characteristics of the Brugada syndrome, were identified in the early 1990s and evolved in parallel with the clinical syndrome (Antzelevitch et al. 1991, 2002 Krishnan and Antzelevitch 1991 Krishnan and Antzelevitch 1993). The ST segment elevation in the Brugada syndrome is thought to be secondary to a rebalancing of the currents active at the end of phase 1, leading to accentuation of the action...

References

Alings M, Wilde A (1999) Brugada syndrome clinical data and suggested pathophysiological mechanism. Circulation 99 666-673 Alings M, Dekker L, Sadee A, Wilde A (2001) Quinidine induced electrocardiographic normalization in two patients with Brugada syndrome. Pacing Clin Electrophysiol 24 1420-1422 Antzelevitch C (2001a) The Brugada syndrome ionic basis and arrhythmia mechanisms. J Cardiovasc Electrophysiol 12 268-272 Antzelevitch C (2001b) The Brugada syndrome. Diagnostic criteria and cellular...

Clinical Features

Quinidine was introduced into clinical drug therapy in the early 1920s (Wenckebach 1923), and syncope following the initiation of the drug was recognized in occasional patients shortly thereafter. The advent of online electrocardiographic monitoring in the 1960s established that quinidine syncope was caused by what we now recognize as torsades de pointes (Selzer and Wray 1964). Interestingly, the actual term was coined to describe the arrhythmia in a different context, an elderly woman with...

Animal Models

Neonatal rat ventricle cell cultures have been employed to demonstrate both the ability of HCN isoforms to enhance automaticity and the contribution of HCN channels to normal automaticity. Qu and colleagues first demonstrated that over-expressing HCN2 in these cultures significantly increased spontaneous rate Fig. 6 Qu et al. 2001 . Er and colleagues subsequently confirmed this observation and extended it to HCN4 over-expression. They also demonstrated that expression of a dominant negative...