low ejection fraction
Introduction
Introduction The ejection fraction, LVEF (Left Ventricular Ejection Fractions), refers to the percentage of stroke volume as a percentage of ventricular end-diastolic volume. When the ventricle contracts, the blood of the ventricle cannot be injected into the artery. Under normal resting state, the volume of ventricular diastolic volume is about 145ml in the left ventricle, about 137ml in the right ventricle, and 60-80ml in the amount of blood. At the end of the ventricle, there is still a certain amount of residual blood. The percentage of the volume of the ventricular diastolic volume is called the ejection fraction. Generally, 50% or more is in the normal range, and the ejection fraction when the human body is quiet is about 55% to 65%. The ejection fraction is related to the contractility of the myocardium. The stronger the myocardial contractility, the greater the stroke volume and the greater the ejection fraction. In the case of abnormal ventricular enlargement and ventricular dysfunction, the stroke volume may not be clearly discriminated from normal people, but it does not match the already increased end-diastolic volume, and the ejection fraction is significantly reduced. A low ejection fraction means that the ejection fraction is below the normal percentage. Patients with cardiac dysfunction are often accompanied by a decrease in ejection fraction. When the ejection fraction is reduced to less than 35%, the chance of sudden death of malignant arrhythmia is greatly increased.
Cause
Cause
Mainly caused by abnormal ventricular enlargement and ventricular dysfunction.
Examine
an examination
Related inspection
M-mode echocardiography (ME) angiography
The two most common diagnostic methods for ultrasound and angiography.
The most common diagnostic methods for ejection fraction are ultrasound and contrast. Of course, the data between each detection method is different. B-ultrasound, cardiovascular ultrasound, is the easiest and most convenient method. Clinically, when a malignant arrhythmia that jeopardizes the life of a patient occurs, drug treatment is usually difficult to work. The only effective treatment is electric shock (electric cardioversion). If the cardioversion cannot be given in time, the patient will die very quickly. Prompt timely use of an automated external defibrillator (AED) or an implantable cardioverter defibrillator (ICD) can save the lives of most sudden death patients.
For various heart diseases, patients with cardiac insufficiency, especially when EF is less than 35%, it is recommended to implant ICD to prevent sudden death.
Diagnosis
Differential diagnosis
Normal heart rhythm originates from the sinus node, frequency 60 times to 100 times / min (adult), comparative rules. Sinus node impulses stimulate the atrium and ventricle sequentially through the normal atrioventricular conduction system, and the conduction time is constant (0.12 to 1.21 seconds for adults). The conduction time of the impulse branch and its branches and the Purkinje fiber to the ventricular muscle is also constant (arrhythmia) (cardiacarrhythmia) refers to any abnormality in the origin of heart rhythm, heart rate and rhythm, and impulse conduction. The meaning of words such as "heart rhythm disorder" or "arrhythmia" is biased towards the abnormality of rhythm, including rhythm and The frequency anomaly is more precise and appropriate.
