LVEF stands for left ventricular ejection fraction.
That leads to another question: what is ejection fraction?
- Remember that stroke volume is the difference between the EDV and the ESV
- Stroke volume = EDV – ESV
- Stroke volume put simply is the volume of blood pumped by the left ventricle every stroke
- Ejection fraction is when we take the stroke volume and divide it by the total volume of blood in the heart at the end of diastole – basically the percentage of total blood in the left ventricle that is actually pumped out by the heart
- LVEF = stroke volume / EDV
- Normal LVEF ranges from 50 to 70 %
- At least half of the blood left in the left ventricle at the end of diastole should be pumped out by the heart during each cardiac cycle
- LVEF between 40 and 50 % is borderline systolic heart failure
- LVEF under 40 % is considered systolic heart failure
- 2 major types of heart failure are defined by the ejection fraction
- Systolic heart failure (HFREF – heart failure with reduced ejection fraction)
- Diastolic heart failure (HFPEF – heart failure with preserved ejection fraction)
- Why is ejection fraction preserved in diastolic heart failure?
- Recall that LVEF = stroke volume / EDV
- In diastolic heart failure, there is an inability for the left ventricle to fill completely, so the EDV is reduced, but stroke volume is also reduced
- As a result, ejection fraction remains preserved
- Why is ejection fraction preserved in diastolic heart failure?
- A common cause for heart failure is ACS and hypertension