1. The phase of the heartbeat when the heart muscle relaxes and the chambers fill with blood.
Usage: Medical/anatomical term; Opposite of systole

Examples

• During diastole, the ventricles relax and fill with blood from the atria.
• The lower number in a blood pressure reading represents diastolic pressure, measured during diastole.
• A normal heartbeat consists of systole followed by diastole.
• Doctors listen for heart sounds that occur during both systole and diastole.
• The diastolic phase allows the heart to rest between contractions.