Potassium channel blocker

Potassium channel blockers used in the treatment of cardiac arrhythmia are classified as class III antiarrhythmic agents.

The prolongation of the action potential duration and refractory period, combined with the maintenance of normal conduction velocity, prevent re-entrant arrhythmias.

[8] A study appears to indicate that topical spray of a selective Tandem pore Acid-Sensitive K+ (TASK 1/3 K+) (potassium antagonist) increases upper airway dilator muscle activity and reduces pharyngeal collapsibility during anesthesia and obstructive sleep apnoea (OSA).

[citation needed] This increases the susceptibility of the myocardium to early Afterdepolarizations (EADs) at low heart rates.

[citation needed] Antiarrhythmic agents that exhibit reverse use-dependence (such as quinidine) are more efficacious at preventing a tachyarrhythmia than converting someone into normal sinus rhythm.