Ejection fraction

Ejection fraction (EF) or ejection fraction is a measure of heart function. You mean the proportion of the heart in one contraction blood, ie the stroke volume ( SV), relative to the total blood volume of the ventricle, so the End-Diastolic Volume ( EDV):

Here, the stroke volume is the difference between end-diastolic and end systolic volume ( ESV ):

The ejection fraction can be measured using different examination methods, in descending order of frequency:

• Echocardiography
• Cardiac catheterization
• Magnetic resonance imaging
• Myocardial scintigraphy or radionuclide ventriculography or Binnenraumszintigrafie.

In clinical practice, the estimation of the ejection fraction is often according to the visual impression; this is considered with subjectively normal pump function than adequate. In cases of impaired pumping function of a quantitative determination using the slice summation method to Simpson should be done; quantification with M-mode according pond wood is considered to be too inaccurate.

Reference values

The European and the American Society of Echocardiography specify matching reference values ​​for the assessment of the global pump function on the basis of ejection fraction.

Clinical Significance

A reduced ejection fraction is used as of objective parameters in addition to the clinical symptoms for the diagnosis of heart failure. In asymptomatic patients, a defined EF < 35-40 %, the presence of left ventricular dysfunction ( NYHA I) and thus the need for a medical heart failure therapy with an ACE inhibitor.

In simultaneous enlargement of the ventricles ( dilatation) and disruption of the spread of excitation ( QRS > 120 ms) or after myocardial infarction <35 % at EF is the implantation of a CRT system indexed with defibrillator function.

A reduced ejection fraction applies in addition to other parameters such as clinical symptoms and laboratory markers as an indicator of poor prognosis in heart failure.