(Pronounced SIS-tuh-lee) Systole is the contraction phase of the cardiac cycle. The word comes from the Greek systolē, from systellein to contract, and is usually associated with ventricular contraction, not atrial contraction.
When your blood pressure is being taken, your systolic pressure (the first number) is the measure of the pressure in your arteries when it is at it’s highest point, just after your heart’s ventricles have contracted, pushing blood around your body.
