Inhibition of KCa2 Channels Decreased the Risk of Ventricular Arrhythmia in the Guinea Pig Heart During Induced Hypokalemia

Hypokalemia reduces the cardiac repolarization reserve. This prolongs the QT-interval and increases the risk of ventricular arrhythmia; a risk that is exacerbated by administration of classical class 3 anti-arrhythmic agents.

Small conductance Ca²⁺-activated K⁺-channels (K_Ca2) are a promising new atrial selective target for treatment of atrial fibrillation. Under physiological conditions, K_Ca2 plays a minor role in ventricular repolarization. However, this might change under hypokalemia because of concomitant increases in ventriculay -60r intracellur Ca²⁺.