description
In phase 3 (the "rapid repolarisation" phase), the L-type Ca2+ channels close, while the slow delayed rectifier (IKs) K+ channels remain open as more K+ leak channels open. This ensures a net outward positive current, corresponding to negative change in membrane potential, thus allowing more types of K+ channels to open. These are primarily the rapid delayed rectifier K+ channels (IKr) and the inwardly rectifying K+ current, IK1 (Kir). This net outward, positive current (equal to loss of positive charge from the cell) causes the cell to repolarise. The currents (IKs and IKr) are generated by K+ efflux mediated by potassium voltage-gated channel subfamily KQT member 1 (KCNQ1 aka Kv7.1) and potassium voltage-gated channel subfamily H member 2 (KCNH2 aka HERG) channels respectively (Park & Fishman 2011, Grant 2009)

external resources
NCBI:1339120
REACTOME:R-HSA-5576890
PUBMED:19808464
PUBMED:21357845

genes
KCNE1 , KCNH2 , KCNQ1 , KCNE2 , KCNE3 , AKAP9 , KCNE5 , KCNE4 ,