Heart ejection fraction (EF) It is an indicator by which the quantitative volume of blood is released into the aorta during an electrical impulse in the left ventricle.
The calculation of this indicator is the proportion of the blood that enters the largest vessel to the amount of blood that is filled with the left ventricle with the weakening of its tissues.
This value, simply calculated, and stores a lot of information about the possibility of contractions of the heart muscle. The definition of PE affects the drugs prescribed for the heart, and also according to EF, life is predicted for people with heart failure.
The closer the VF indicators are to the normal, the better the heartbeat will be. If the ejection fraction deviates below normal values, this indicates that the heart can not contract at a normal rate, which leads to poor blood circulation.
In such situation, an urgent need to seek medical advice.
How is the calculation of PV?
The calculation of this fraction is not difficult, but it stores a large amount of information about the heart muscle and its capacity for normal contractions.
In many cases, Doppler ultrasound of the heart is used to determine the ejection fraction.
Calculation of PV.
The fraction index is calculated using the Teuholz formula or the Simpson formula. All calculation errors occur with the help of a program that automatically generates a result, depending on the amount of blood in the left ventricle without pressure, which is pushed into the aorta.
The main differences of the previous formulas are:
- According to the formula of Teuholz. The amount of blood expelled from the ventricle is determined by an M-modal ultrasound examination. This formula was patented by Teuholz in nineteen seventy six.
- A small part of the ventricle is examined at its base, the length is not taken into account. False results obtained by the formula can occur during ischemic attacks, when the contractions are altered in certain areas of the heart muscle.
- The program takes into account the information about the volume in a relaxed and shortened left ventricle, giving the result automatically. This method is used in computers that are not currently updated.
- According to Simpson’s formula. A quantitative two-dimensional ultrasound examination of the heart is performed, with which more accurate results are obtained. Simpson’s algorithm was patented by him in nineteen eighty-nine. The identical name for this algorithm is the disk method. In this study of the ejection fraction, all the important areas of the cardiac muscle are examined.
Fact The indicators of the results of the study of the same patient, according to different formulas, can vary with a difference of ten percent.
What characteristics does the PV have?
The main characteristics inherent to the ejection fraction are the following:
- The VF does not depend on the genre.
- With age, there is a decrease in the ejection fraction due to the aging of the body.
- The indicators of lower fractions can be normal individually, but they should not be below forty-five percent.
- The growth of ejection fraction results is also present in healthy people, with an increase in heart rate and with an increase in pressure.
- When the level falls below thirty-five percent, irreversible deviations in the myocardium are involved.
- Newborns have an overestimated rate of ejection fraction (up to 80 percent)
- The definition of EF affects the prediction of heart disease.
The individual indicators of ejection fraction are considered normal for a person, since for different age categories of people, their levels can vary. In addition, the levels of the ejection fraction rule depend on the calculation formula and the equipment in which the analysis is carried out.
The average of the generally accepted normal value:
- For Simpson’s formula, it is between fifty and sixty percent, with an extreme lower bar of forty-five percent.
- According to the Teuholz formula, the extreme lower limit is fifty-five percent. The indicator on the lower bar determines that it is this percentage of blood that must be compressed in the aorta so that the organs receive the correct amount of oxygen.
- In the case of heart failure, the rates vary from thirty-five to forty percent. In this condition, medical maintenance of the body, or surgical intervention is necessary.
- With rates lower than 35 percent, there may be early burdens, as well as death.
In childhood, ejection fraction rates increase slightly. In newborns, it is not less than sixty percent and can reach eighty.
As the child develops and grows, the level of the ejection fraction returns to normal.
With deviations, in most cases, there is a decrease in the ejection fraction, instead of its growth. Various pathological conditions affect the reduction of FE levels.
When the ejection fraction rate is below normal, it indicates that the myocardium can not contract at a normal rate. It leads to an alteration of the blood circulation in the body and the lack of oxygen in the organs.
Initially, the brain suffers from hypoxia.
In some cases, the results of the study show the limits of the emission fraction above 60 percent. In many cases, they do not exceed 80 percent, since a healthy left ventricle can not shed more blood to the aorta because of its structural characteristics.
In addition, with an abnormal increase in the heart muscle, an increase in the ejection fraction rate may indicate that the myocardium can not restore progressive heart failure and is trying to inject as much blood into the aorta.
With the progression of heart failure, the ejection fraction decreases. That is why it is important to monitor deviations of the VF in one direction or another, and immediately contact the hospital for examination.
Why is decadence happening?
The initial stages of progression of heart disease do not affect the rate of ejection fraction. This happens because the heart muscle tries to adapt to the changes (the myocardial layer increases, accelerates its contractions, rebuilds the small vessels of the heart).
Take a look at what is the compensation mechanism of the heart muscle.
With the development of the disease, the muscle wears down more and more, which leads to deviations of the functional capacities, which entail structural disorders. All this violates the amount of blood thrown by the left ventricle into the aorta, causing interruptions in blood circulation.
Such deviations cause everything that negatively affects the heart muscle: