Quinidine Reduces the Interfacial Electrical Heterogeneity of the Right Ventricular Outflow Tract Free Wall's Transient Outward Potassium Current

k. Dr. Venkatewara rao

» doi: https://jcdponline.org/.2010.v01.i01.pp01-09

Abstract

One of the primary electrophysiological substrates for Brugada syndrome is the electrical heterogeneity of the right ventricular outflow tract (RVOT). The capacity of quinidine to suppress potassium current, and more specifically the 4-aminopyridine-sensitive, non-Ca2+-dependent transient outward potassium current (Ito), has led to its recent use as an effective treatment for Brugada syndrome. The degree to which quinidine in the therapeutic concentration range may block this kind of electrical heterogeneity of RVOT Ito is, however, far less well understood. Approach and Outcomes—The results of whole-cell voltage clamping were acquired at 37°C with a 0.2 Hz depolarization pulse using single RVOT free wall epicardial (Epi), midmyocardial (M), and endocardial (Endo) cells. Within the RVOT free wall, there was clearly some transmural variability. According to the results (between groups, P<0.01), the total transmural average Ito values of the RVOT free wall were 10.2 pA/pF,