Cardiac transient outward potassium current

It is a result of the movement of positively charged potassium (K+) ions from the intracellular to the extracellular space.

Ito1 is complemented with Ito2 resulting from Cl− ions to form the transient outward current Ito.

This outward flow of positively charged ions constitutes the Ito1 and causes the transmembrane voltage to decrease.

Ito1 is then quickly deactivated, stopping the repolarization and ending the phase 1 of the action potential.

[2] In addition, several regulatory subunits and pathways modulating the level and biophysical properties of cardiac Ito have been identified.

The cardiac action potential has five phases. I to1 is active during phase 1, causing a fast repolarization of the action potential