Phase IV: isovolumetric relaxation period – both valves are closed and the intraventricular pressure decreases without a change in blood volume. Changes in aortic, left ventricular and left atrial pressure were represented graphically as a function of time, with the corresponding electrocardiogram signal for everyone. LVP = left ventricular pressure. ventricular ejection phase: second phase of the ventricular systole, in which blood is pumped out of the occlusion of the ventricle valve and the phases of rapid filling are audible with a stethoscope on the chest and can be recorded phonocardiographically after electronic amplification. The first cardiac tone resulting from cardiohema vibrations with closure of the AV valves (mitral valves, tricuspids) announces a ventricular systole. The second heart tone, shorter and composed of higher frequencies than the first, is associated with the closure of the crescent-shaped valves (aorta and pulmonary) at the end of the ventricular sputum. The sounds of the third and fourth cores are low-frequency vibrations caused by rapid early filling and late diastolic anterior contractile filling, respectively. These sounds can be heard in normal children, but in adults they usually indicate a disease. Isovokal ventricular relaxation phase: Initial phase of the ventricular diastole, when the pressure in the ventricles of the two main arteries, the pulmonary trunk and the aorta, falls below the pressure and the blood tries to flow back into the ventricles, creating the dicrotic notch of the ECG and closing the two crescent valves Figure 1.
A schematic diagram of the three main phases of filling and emptying four heart chambers of the fish heart. (a) The atrium and ventricle fill due to venous blood pressure. b) The atrium contracts (as indicated by the small arrows), expands further and completes the filling of the ventricle. c) The ventricle contracts and expels fluid into the atheroscopy bulb. At the same time, the atrium begins to fill up. Figure 12.3. Evaluation of regional and global longitudinal elongation of longitudinal left ventricular elongation. The heart cycle is the performance of the human heart from the beginning of one heartbeat to the beginning of the next.
It consists of two periods: one during which the heart muscle relaxes and replenishes into blood, called diastole, after a period of robust contraction and pumping of blood, called systole. After emptying, the heart immediately relaxes and expands to receive another influx of blood that returns from the lungs and other body systems before contracting again to pump blood into the lungs and these systems. A normally performing core must be fully expanded before it can pump again effectively. Assuming a healthy heart and a typical rhythm of 70 to 75 beats per minute, each heart cycle or heartbeat takes about 0.8 seconds to complete the cycle.  There are two ear chambers and two ventricular chambers of the heart; They are paired like the left heart and the right heart – that is, the left atrium with the left ventricle, the right atrium with the right ventricle – and they work together to continually repeat the cardiac cycle (see the cycle chart on the right edge). At the beginning of the cycle, during ventricular diastole, the heart relaxes and expands by absorbing blood in both ventricles through both atria; Then, towards the end of the late ventricular diastole, both atria begin to contract (atrial systole), and each atrium pumps blood into the ventricle below.  During ventricular systole, the ventricles contract and pulsate (or expel) two separate stores of blood from the heart – one to the lungs and one to all other organs and systems in the body – while both atria are relaxed (atrial diastole). This precise coordination ensures that blood is collected and circulates efficiently throughout the body.  Figure 6.3. Relationship between left ventricular volume and intraventricular pressure during systole and diastole.
Stages 1 and 2 together – “isovolumic relaxation” plus influx (equivalent to “rapid influence”, “diastasis” and “atrial systole”) – include the “diastole” ventricular period, including the atrial systole, in which blood returning to the heart flows through the atria into the relaxed ventricles. Stages 3 and 4 together – “isovolumic contraction” plus “sputum” – are the ventricular period “systole”, which is the simultaneous pumping of blood supplies separated from the two ventricles, one to the pulmonary artery and the other to the aorta. Remarkably, towards the end of the “diastole”, the atria begin to contract, and then pump blood into the ventricles; This pressure delivery during ventricular relaxation (ventricular diastole) is called the atrial systemstole, also known as the atrial kick. [Citation needed] Figure 12.5. Right ventricular form in a normal and pathological condition. Under normal load conditions, the right ventricle (RV) appears crescent-shaped in cross-section (a) and triangular in the sagittal plane (c), and the interventricular septum is concave in the systole and diastole towards the LV. With RV pressure and volume overload, there may be a left deviation of the interventricular septum, which leads to a reduction in the LV cavity and impaired LV function (b and d). In this patient, an enddyastolic LV sphericity index (main axis LV/secondary axis LV) = 2(b) identifies a severe change in LV morphology due to severe pulmonary hypertension. The cardiac cycle refers to all the events that occur from the beginning of a heartbeat to the beginning of the next and can be divided into two parts: a period of relaxation known as diastole and a period of contraction known as systole.
The changes in pressure and volume that occur during the cardiac cycle of the left ventricle are illustrated in Figure 6.2 and serve as a platform to describe important events. It is important to note that these changes for the left ventricle shown here also occur simultaneously in the right side of the heart in the right atrium, right ventricle and pulmonary artery….