What happens during isometric ventricular contraction of the cardiac contraction cycle?

False-during the isometric (or isovolumic) ventricular contraction phase of the cardiac contraction cycle, yes there is an increase in ventricular pressure; but the consequence of this is the closing of the av valves, not the semilunar valves. the semilunar valves only open when the pressure in the ventricles exceed the pressure in the pulmonary or aortic arteries, which occurs during the ventricular ejection phase. also its important to note here that the volume in ventricle is not changing (isovolumic) and the heart muscle cells cant shorten. the volume of blood in the ventricle at this point is the edv (end diastolic volume).