Inhibition of cardiac Kv4.3 (Ito) channel isoforms by class I antiarrhythmic drugs lidocaine and mexiletine

Transient outward K+ current, Ito, contributes to cardiac action potential generation and is primarily carried by Kv4.3 (KCND3) channels. Two Kv4.3 isoforms are expressed in human ventricle and show differential remodeling in heart failure (HF). Lidocaine and mexiletine may be applied in selected patients to suppress ventricular arrhythmias, without effects on sudden cardiac death or mortality. Isoform-dependent effects of antiarrhythmic drugs...