As a cardiovascular specialist with a focus on the mechanics of the heart, I can explain the difference between systole and diastole in detail. Systole refers to the phase of the cardiac cycle during which the heart muscle (myocardium) contracts. This contraction pushes blood out of the heart and into the arteries, resulting in the highest pressure within the arterial system. The systolic pressure is the top number in a blood pressure reading and is a measure of this peak pressure. Diastole, on the other hand, is the phase when the heart muscle is relaxed between contractions. This is the time when the heart refills with blood coming from the veins. The diastolic pressure is the bottom number in a blood pressure reading and represents the pressure in the arteries when the heart is at rest. The difference between systolic and diastolic pressures is known as the pulse pressure. It reflects the amount of pressure change that occurs during one heartbeat and can be an indicator of various cardiovascular conditions. read more >>

The top number is the maximum pressure your heart exerts while beating (systolic pressure), and the bottom number is the amount of pressure in your arteries between beats (diastolic pressure). The numeric difference between your systolic and diastolic blood pressure is called your pulse pressure.read more >>