Cardiac repolarization is a normal cardiac electrophysiological phenomenon, a process in which the heart undergoes depolarization followed by a resting state in which the membrane potential and current direction are restored. A cardiac cycle includes two processes of depolarization and repolarization. When depolarization occurs, the electrical signal is sent from the sinoatrial node to the atria, then through the atrioventricular node to the atrioventricular bundle, and then through the left and right bundle branches, and then through the Purkinje fibers to the left and right ventricles, and then from the endocardium to the ectocardium to synchronize the contraction of the whole heart. The membrane charge of the cardiac cells also changes from the resting state, which is positive on the outside and negative on the inside, to the activated state, which is negative on the outside and positive on the inside. Repolarization is the opposite of the above, and the direction of repolarization is transmitted from the outer membrane to the inner membrane. At this time, the heart is in a diastolic state, and the surface charge of the heart is restored to the state before depolarization, and it is restored from outer-negative to inner-negative, so as to be ready for the next depolarization. If you have any symptoms of cardiac discomfort, you need to go to the hospital as soon as possible, and the doctor will formulate an individualized diagnosis and treatment plan according to your specific condition, so as not to delay your condition.