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An ejection fraction (EF) is the volumetric fraction ... However, in 1856 Chauveau and Faivre [25] observed that some fluid remained in the heart after contraction.
Heart failure with preserved ejection fraction (HFpEF) is a form of heart failure in which the ejection fraction – the percentage of the volume of blood ejected from the left ventricle with each heartbeat divided by the volume of blood when the left ventricle is maximally filled – is normal, defined as greater than 50%; [1] this may be measured by echocardiography or cardiac catheterization.
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 ...
Heart failure with mildly reduced ejection fraction (HFmrEF), previously called "heart failure with mid-range ejection fraction", [63] is defined by an ejection fraction of 41–49%. [ 63 ] Heart failure with preserved ejection fraction (HFpEF): Synonyms no longer recommended include "diastolic heart failure" and "heart failure with normal ...
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.
This is defined as a left ventricular ejection fraction (LVEF) of 40% or less. About half of heart failure patients have a reduced ejection fraction. [2] Other types of heart failure are heart failure with mildly reduced ejection fraction (LVEF between 40% and 50%) and heart failure with preserved ejection fraction (LVEF 50% or higher). [1] [3]
During "ejection" stage, the (red-line) tracing of "ventricular volume" falls to its least amount (see ejection fraction) as the ventricles pump blood to the pulmonary arteries and to the aorta. The cardiac cycle involves four major stages of activity: 1) "isovolumic relaxation", 2) inflow, 3) "isovolumic contraction", 4) "ejection".
Ejection fraction: 66% (± 6%) [2] 67% (± 4.6%) [3] Heart rate: 60–100 bpm [4] 60–100 bpm [4] Cardiac output: 4.0–8.0 L/minute [5] 4.0–8.0 L/minute [5]