Diastole — ECG/EKG Terminology

Definition: Relaxation phase of the heartbeat. From the Greek diastole, meaning dilation.

Key Facts

• Phase when ventricles relax and fill with blood.
• Includes most coronary perfusion time in the left ventricle.
• Shortened diastole during tachycardia can worsen ischemia.

ECG Connection: Ventricular repolarization (T wave) is followed by the diastolic filling period.

Why It Matters: Rate control can improve perfusion by restoring adequate diastolic filling time.