enddiastolic volume (PDE): (also preloaded) of the amount of blood in the ventricles at the end of the atrial system shortly before ventricular contraction A P-V loop can also be described for atrial events (Hoit et al., 1994). During ventricular sputum, the descent of the ventricular base lowers the ear pressure, thus promoting ear filling. Filling the atria of the veins leads to a V wave on the atrium and a follow-up of the venous pressure. When the mitral and tricuspid valves open, the blood stored in the atria empties into the ventricles. Anterior contraction, characterized by an A wave on the monitoring of ear pressure, actively supports ventricular filling. The resulting P-V ear chart has an eight-digit configuration with a clockwise V-loop representing passive filling and emptying of the earcups, and an A-loop counterclockwise representing active atrial contraction. Thus, the atria act as a reservoir and channel for venous discharge (during ventricular systole or diastole) and as an overpressure pump for ventricular filling late in the diastole. To represent the cardiac cycle, aortic pressure, left ventricular pressure, left ear pressure, left ventricular volume and ECG are placed on a figure applied against time (Fig. 5.10; a similar image can be drawn for the right side of the heart, with pressure values that represent about one sixth of the value relative to the left side of the heart). Remember that the ECG-P wave is associated with atrial depolarization. During this time, the mitral valve is opened, and the left atrium forces the remaining blood into the left ventricle, effectively preparing the left ventricles for contraction.
This priming effect occurs because for much of the left ventricular diastole (and left atrial diastole), the left atrial pressure is higher than the left ventricular pressure, suggesting that the mitral valve is open. Any blood that passes from the venous pulmonary circulation into the left atria goes directly into the left ventricles. Therefore, a constant increase in ventricular volume can be observed during the diastolic part of the cardiac cycle. During atrial systole, 10-20 ml of blood is squeezed into the ventricles, thereby expanding ventricular muscle mass. This expansion, in addition to the contraction of the muscles of the ventricle, causes an initial reaction of elastic recoil to move blood through the cardiovascular system. Again, note that although we are talking about the left side of the heart, the same pattern is observed on the right side of the heart (for example. B, during ventricular diastole, blood from the right atria passes directly into the right ventricles). Due to the contractions of the systoles, the pressures in the ventricles increase rapidly, exceed the pressures in the trunks of the aorta and pulmonary arteries and cause the opening of the necessary valves (the aortic and pulmonary valves) – which leads to the expulsion of separate blood volumes from the two ventricles. This is the sputum phase of the cardiac cycle; It is represented (see pie chart) as the first phase of the ventricular systole, followed by the second phase of the ventricular systole. Once the ventricular pressures have fallen below their extremities and below those in the trunks of the aorta and pulmonary arteries, the aortic and pulmonary valves close – see the Wiggers diagram on the right, Blue Line Tracing.
Temporal increases and decreases in the heart`s blood volume (see Wiggers diagram) are also instructive to follow. The red line of the „ventricular volume“ provides an excellent trace of the two periods and four stages of a cardiac cycle. Starting with the diastole period: the low-volume plateau of the „Isovolum Relaxations“ stage, followed by a rapid climb and two slower climbs, all the components of the „entry phase“ – up to the high volume plateau of the „Isovolum Contractions“ stage; (Find the legend on the left side of the chart.) Then the systole, including the high stage of „isovolumic contraction“, until the rapid decrease in blood volume (i.e. the vertical fall of the red line tracking), which indicates the emptying of the ventricles during the „sputum“ phase of the completed cycle – all equal to a heartbeat. [Citation needed] Valve closure and rapid filling phases 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 early rapid filling and fast power, respectively. late diastolic anterior contractile filling is caused. These sounds can be heard in normal children, but in adults they usually indicate a disease.
In a normal and healthy heart, there are only two audible heart murmurs: S1 and S2. S1 is the sound produced by the closure of the atrioventricular valves during ventricular contraction and is usually described as „lub“ or first heart tone. The second cardiac tone, S2, is the sound of crescent-shaped valves that close during the ventricular diastole and is described as a „dub“ (Figure 3). In both cases, when the valves close, the openings inside the atrioventricular septum guarded by the valves are reduced, and blood flow through the opening becomes more turbulent until the valves are completely closed. .