A printer friendly page is available here. 120 mm Hg Diastolic pressure - lowest pressure produced during heart relaxation. Let's look at the cardiac cycle strictly in terms of pressure and volume in the left ventricle. Phase I Ventricular filling. Volume increases in ventricle up to 130 ml but pressure remains constant Phase II Isovolumetric ventricular contraction.
Volume remains constant, no flow.
Isometric cardiac muscle contraction produces tension but no shortening, pressure increases to 80 mm Hg then aortic valves open Phase III Ventricular emptying.