Triggers for arrhythmogenesis in the Brugada and long QT 3 syndromes

The first sign for BrS and LQTs patients may be sudden death. The triggers for these sudden deaths include exercise, fever, ischemia, and drug use. In this paper we review the effects of acidosis and fever on BrS and LQTs, discuss Brugada phenocopy syndrome drawing from published literature, and present our own patch-clamp data from mutant channels at low pH. We show that, at low pH, there is a preferential block of peak currents and preferential increase of persistent current in a common BrS/LQTs mutant compared to wild type sodium channels. Our data complements the existing literature on the importance of environmental triggers to arrhythmias.