The systolic phase indicates the contraction of the atrium and the ventricle whereas the diastole phase represents the relaxation of both of them. Systole takes place as atrium systole in which atria contracts to push the blood in the ventricles and ventricular systole during which ventricles contract to push the blood in the aorta and the pulmonary artery. While diastole takes place as joint diastole and during this time, the atria and the ventricles relax to fil in the blood through the veins in the atria and some blood leaking into the ventricles.