Sotalol is a nonselective beta-adrenergic receptor antagonist that also blocks potassium currents.

Sotalol prolongs action potential duration, decreases automaticity, slows impulse transmission through the AV node and prolongs AV nodal refractoriness.

It is used in management of ventricular tachyarrhythmias and is also used in treatment of atrial arrhythmias.

Antiarrhythmic effects are due both to beta-adrenergic receptor and potassium channel blockade.

Normally, sympathetic drive results in increased in Ca²⁺ ,K⁺ ,and Cl^- currents.

• Increased sympathetic tone also increases phase 4 depolarization (heart rate goes up), and increases DAD (delayed afterdepolarizations) and EAD (early afterdepolarization) mediated arrhythmias.

• These effects are blocked by beta-adrenergic receptor blockers.