What mechanism that high potassium causes cardiac arrest? i just know high k+ causes hyper excitability of cells?

Cell repolarization: When cardiac muscle cells fire, they use up part of the electrochemical gradient they maintain in life. They are repolarized by an outward potassium (K+) flux across the plasma membrane. This outward K+ current depends on the K+ electrochemical gradient. If the "outside" K+ (in blood & interstitial fluid) is very high, that destroys the K+ electrochemical gradient, the cells can't repol; they stop