Repolarization

Repolarization is a stage of the cardiac cycle, specifically in the process of cardiac action potential. It refers to the change in membrane potential that returns it to a negative value after the depolarization phase of an action potential has just previously changed the membrane potential to a positive value. The repolarization phase usually returns the membrane potential back to the resting state. This process is essential for the preparation of the cardiomyocytes for the next action potential.

Process

During the repolarization phase, the cell membrane's permeability to potassium is increased, allowing these ions to move out of the cell. This outward movement of positive ions decreases the membrane potential back to its resting value. The sodium-potassium pump also plays a role in maintaining the resting potential after repolarization.

Role in Cardiac Cycle

In the cardiac cycle, repolarization occurs following the depolarization phase. This is seen in the QRS complex on an electrocardiogram (ECG), where repolarization corresponds to the T wave. Abnormalities in repolarization can lead to various cardiac conditions, such as Long QT syndrome and Brugada syndrome.

See Also

• Depolarization
• Hyperpolarization
• Resting potential
• Action potential

Repolarization

• Action Potential
  Action Potential