You should be able to relate the various charts in the figure to the 6 phases shown at the bottom of the page. To help you with those phases, please refer to the information I have given below. I will be referring only to what happens in the left side of the heart. This is termed ventricular filling . During this phase the left AV valve is open and the Aortic valve is closed .
Blood flows into the left atrium from the pulmonary veins and then into the left ventricle.
The P wave occurs at the end of this phase and causes the next phase. During the phase of atrial contraction the left atrium contracts and sends more blood into the left ventricle. At the end of this period you have the end diastolic volume. The left AV valve is still open and the Aortic valve is closed . Initially the Aortic valve is also closed since the blood pressure in the ventricles is still below the blood pressure in the aorta.