As a domain expert in cardiology, I can explain the concepts of repolarization and relaxation in the context of the cardiac cycle. Repolarization and relaxation are related but distinct processes in the cardiac cycle. Repolarization refers to the return of the membrane potential in cardiac muscle cells towards its resting state after a depolarization event. This occurs during the T wave in the ECG and signifies the end of the ventricular contraction phase. On the other hand, relaxation is the period during which the ventricles return to their resting state after contraction. It is a broader term that encompasses the end of contraction and the beginning of the filling phase of the heart. So, while repolarization is a part of the relaxation process, it is not synonymous with the entire relaxation period. Repolarization is the electrical event that marks the transition from contraction to relaxation, but relaxation also includes the mechanical aspects of the heart returning to its resting state. read more >>

P?wave �� atrial depolarization (upward deflection, beginning of atrial contraction) QRS complex �� ventricular depolarization (ventricular contraction) T?wave �� ventricular repolarization (upward deflection, beginning of ventricular relaxation)read more >>