Quinidine Depresses the Transmural Electrical Heterogeneity of Transient Outward Potassium Current of the Right Ventricular Outflow Tract Free Wall

Abstract

Background—Electrical heterogeneity of the right ventricular outflow tract (RVOT) is regarded as one of the main electrophysiological substrates for Brugada syndrome. Recently quinidine has shown efficacy in patients with Brugada syndrome due to its ability to inhibit potassium current especially 4-aminopyridine–sensitive, non-Ca2+-dependent transient outward potassium current (Ito). However, much less is known on how extent quinidine in clinical therapeutic concentration range can inhibit this kind of electrical heterogeneity of RVOT Ito.