Cardiac myocyte repolarization

Cardiac myocyte repolarization is the process by which cardiac muscle cells restore their negative resting membrane potential after depolarization and contraction. This phase, mainly corresponding to phase 3 of the cardiac action potential, is orchestrated predominantly by the opening of various potassium (K⁺) channels, closing of calcium (Ca²⁺) channels, and activity of ion exchangers and pumps such as the sodium-potassium pump. Multiple ion channel types are involved, especially the delayed rectifier potassium channels (such as I_Kr and I_Ks) and inward rectifier K⁺ channels. Disruption of this process, by either genetic or pharmacological factors, can lead to abnormal cardiac rhythms and is a primary cause of acquired or inherited long QT syndrome, making the constituent ion channels the true therapeutic targets, not the process itself.

Other names

Repolarization of cardiac myocytesCardiac repolarizationMyocyte repolarizationPhase 3 of cardiac action potential