;IKr blockade On EKG, the QT interval represents the summation of action potentials in cardiac muscle cells. QT<unk>  therefore results from action potential<unk> , which can be caused by an increase in inward current through sodium or calcium channels, or a decrease in outward current through potassium channels. By binding to and inhibiting the “rapid” delayed rectifier potassium current protein, IKr, which is encoded by the hERG gene, certain<unk> s are able to decrease the outward flow of potassium ions and extend the length of phase 3 myocardial repolarization, which is reflected as QT<unk> .
Drug-induced QT prolongation
Benign early repolarization
Catecholaminergic polymorphic ventricular tachycardia
Tachycardia-induced cardiomyopathy
Sudden arrhythmic death syndrome
Toxic anterior segment syndrome
Pre-excitation syndrome
Long QT syndrome