The effect of low potassium in Brugrada Syndrome: A simulation study

Brugada Syndrome (BrS) is associated with an increased risk of ventricular arrhythmias. It is caused by ion channel abnormalities and is characterized by coved ST elevation, J wave appearance and negative T waves in the right precordial electrocardiographic lead. The changes in the electrocardiogram (ECG) in the setting of BrS can be due to reduced inward currents, increased outward currents (I_to) and fibrosis. Some clinical reports relate hypokalemia to arrhythmic events (in the presence of other pathologies). Hypokalemia contributes to ST-segment elevation and changes in the T-wave morphology. It seems plausible that in patients with BrS, low extracellular potassium concentration ([K⁺]_o) might increase repolarization gradients, especially in right ventricle (RV), setting the stage for ventricular arrhythmia. The main goal of this study is evaluate the effect of low [K⁺]_o in BrS using a mathematical modeling approach. Our results show that transmural dispersion of repolarization (TDR) was augmented in hypokalemic conditions. Furthermore, T_peak-T_end interval was calculated from the pseudo-ECG and was increased by 14 and 51 % in BrS and in BrS combined with hypokalemia, respectively, with respect to control. Additionally, a prominent J wave was observed in BrS and this increased if hypokalemia was also introduced.