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 (Ito) 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, Tpeak-Tend 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.