Answer:
repolarization
Explanation:
Potassium channel blockers are drugs that interfere with the flow of potassium ions (K+) through potassium channels in cell membranes, thereby prolonging the duration of the action potential (repolarization phase). For example, amiodarone is a class III antiarrhythmic agent whose target is HERG human cardiac K+ channel. This drug (amiodarone) acts by prolonging the repolarization phase of the cardiac action potential.