Diastole on an EKG is represented by which wave?

The T-wave on an EKG represents the process of repolarization of the ventricles after they have contracted. Diastole is the phase of the cardiac cycle when the heart muscle relaxes and the chambers fill with blood. Specifically, the T-wave occurs after the QRS complex, which indicates ventricular depolarization (contraction), and signifies that the ventricles are preparing to enter the diastolic phase.

During diastole, the heart's chambers relax and fill with blood, and the completion of repolarization is displayed as the T-wave on the EKG. While the P-wave indicates atrial depolarization and the QRS complex represents ventricular depolarization, neither of those directly correlates with the relaxation phase of the heart. The U-wave, in most cases, is not routinely seen and is associated with specific conditions, rather than the standard representation of diastole. Therefore, the T-wave is the correct representation of diastole on an EKG.