HERG inhibitors, short for human ether--go-go-related gene inhibitors, belong to a specific class of compounds that interact with a critical ion channel in the human heart known as the hERG potassium channel. These channels play a fundamental role in regulating the electrical activity of cardiac cells, specifically in the repolarization phase of the cardiac action potential. The hERG channel is responsible for the efflux of potassium ions from cardiac cells, which is essential for maintaining the heart's rhythm and preventing the development of life-threatening arrhythmias. Therefore, HERG inhibitors are compounds that have the capacity to modulate the activity of these channels, often by blocking or inhibiting their function.At the molecular level, HERG inhibitors primarily target the hERG channel's pore-forming α-subunit, which consists of six transmembrane segments (S1-S6) and a pore loop (P-loop) region. These inhibitors typically bind to specific sites within the channel, obstructing the flow of potassium ions through the pore. This interference with potassium ion flow can have significant consequences on the cardiac action potential, leading to prolongation of the repolarization phase, a phenomenon known as QT interval prolongation. Prolonged QT intervals can increase the risk of potentially life-threatening arrhythmias, such as torsades de pointes.