Blood pressure may be defined as the force of blood inside the blood vessels against the vessel walls (Marieb and Hoehn [110]). Systolic pressure is the peak pressure caused by the left ventricle contracting and blood entering the aorta, which causes the aorta to stretch; therefore, systolic pressure in part reflects the function of the left ventricle (Waugh and Grant [207]). Diastolic pressure is caused by the aortic valve closing, blood flowing from the aorta into the smaller vessels and the aorta recoiling back (Marieb and Keller [111]). This is when the aortic pressure is at its lowest and tends to reflect the resistance of the blood vessels (Marieb and Hoehn [110]).