repolarization /rēpō′lərīzā″shən/ [L, re + polus, pole; Gk, izein, to cause] , the process by which the membrane potential of a neuron or muscle cell is restored to the cell’s resting potential. In a cardiac muscle cell, the repolarization process begins after phase 0 of the action potential and is completed by the end of phase 3. It encompasses the effective and relative refractory periods and correlates with the Q-T interval on the electrocardiogram. See also cardiac action potential.
