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Stroke volume is an important determinant of cardiac output, which is the product of stroke volume and heart rate, and is also used to calculate ejection fraction, which is stroke volume divided by end-diastolic volume. Because stroke volume decreases in certain conditions and disease states, stroke volume itself correlates with cardiac function.
Major factors influencing cardiac output – heart rate and stroke volume, both of which are variable. [1]In cardiac physiology, cardiac output (CO), also known as heart output and often denoted by the symbols , ˙, or ˙, [2] is the volumetric flow rate of the heart's pumping output: that is, the volume of blood being pumped by a single ventricle of the heart, per unit time (usually measured ...
This gives an LV stroke volume of 3.14 * 24 = 75.40 cc. Divide the LV stroke volume, 75.40 cc by the Aortic Valve VTI, 50 cm and this gives an aortic valve area of 75.40 / 50 = 1.51 cm 2. The weakest aspect of this calculation is the variability in measurement of LVOT area, because it involves squaring the LVOT dimension.
The Frank–Starling law of the heart (also known as Starling's law and the Frank–Starling mechanism) represents the relationship between stroke volume and end diastolic volume. [ 1] The law states that the stroke volume of the heart increases in response to an increase in the volume of blood in the ventricles, before contraction (the end ...
End-systolic volume ( ESV) is the volume of blood in a ventricle at the end of contraction, or systole, and the beginning of filling, or diastole . ESV is the lowest volume of blood in the ventricle at any point in the cardiac cycle . The main factors that affect the end-systolic volume are afterload and the contractility of the heart .
Based on the Bernoulli equation for incompressible fluids, the product of VTI (cm/stroke) and the cross sectional area of any cardiac structure (cm 2) yields a stroke volume (cm 3 /stroke), which can be used to calculate cardiac output. Qp = VTI RVOT × π × (d RVOT / 2)² <=> Qp = VTI RVOT × 0.785 × d RVOT ²
In a piston engine, the static compression ratio ( ) is the ratio between the volume of the cylinder and combustion chamber when the piston is at the bottom of its stroke, and the volume of the combustion chamber when the piston is at the top of its stroke. [ 9] It is therefore calculated by the formula [ 10] where. is the displacement volume.
The Otto cycle is a description of what happens to a gas as it is subjected to changes of pressure, temperature, volume, addition of heat, and removal of heat. The gas that is subjected to those changes is called the system. The system, in this case, is defined to be the fluid (gas) within the cylinder.