Ejection Fraction

What ejection fraction stands for is the amount of blood which enters the heart that is actually pumped out. So if 100cc's of blood enters the heart, and 55 cc's are pumped out, your ejection fraction would be 55%.

What is considered abnormal or low EF levels?

If the ejection fraction is under about 50%, then patients can start having heart failure. This means the heart is not pumping enough blood out of its chamber to fulfill the body's needs. And the blood can often times back up into the lungs and can fill the lungs with fluid.

Patients who have heart failure who have low ejection fractions will often times get short of breath, often times will have fluid building up in their legs, their legs will become swollen. And if you have a weak heart, the heart also becomes subject to rhythm problems.

If it continues to drop, it needs to be treated, otherwise those patients, many of them, will die suddenly.

How do you measure an Ejection Fraction?

Ejection fraction can be measured by a number of techniques.

One technique is with a cardiac ultrasound called an echocardiogram where you simply put a transducer on the chest and you can look, basically utilizing ultrasound images like when they look at a woman who's pregnant and look at the baby in the womb. You can look at the heart beat and you can measure the ejection fraction visually utilizing computer algorithms and see what percentage of blood is pumped out with every heart beat. Other ways include stress testing, cardiolite scans, cardiolite stress test will often times be utilized for ejection fraction.

There's two other techniques: one is utilizing something called a ventriculogram where you put a catheter in the heart and you can actually measure how much x-ray dye gets pumped out of the heart by injecting x-ray dye inside the middle of the heart and see how much gets pumped out. The final way is a fancy x-ray called a muga scan which is a radiology test that measures ejection fraction.

Who should know their EF Number?

The ejection fraction test is an important one.

Basically, most patients who have had any type of heart disease should know their EF. I think it's just like your cholesterol or your blood pressure. If you've ever had any heart problems, one of the things you want to know is not only your blood pressure, not only your cholesterol, but also your ejection fraction.

If a patient is young and otherwise healthy, they probably don't need to have it very often because you have no reason to think its going to be impaired. So maybe every 5 or 10 years, patients should have a stress test.

If somebody has had a weakened heart, or if they have blocked arteries or if they have needed a stent, or if they've had a heart attack, or they've had open heart surgery, those patients may have ejection fraction which is 50% which is normal earlier and after they've had a big heart attack or major open heart surgery or procedure, may be 30%. Those patients you need to re-measure it and you probably want to measure it yearly in those patients.

What is a normal vs. abnormal EF?

The heart doesn't always pump out all the blood that enters it. Ordinarily, it pumps out about 50 or 60% of the blood that enters it at any given heart beat and leaves about 40% behind. That's normal ejection fraction: it should be 50 – 60%.

Patients who have had heart attacks or who have other injuries to the heart will often times have a lower ejection fraction. The heart doesn't work as powerfully. It becomes slow and boggy. It doesn't have the power to pump out all of the blood that fills it between heart beats. Ejection fraction can get as low as 10% and this causes a lot of problems: you end up with a heart that's dilated, that's doesn't pump a lot of blood out. Instead of running on a V8, some patients end up having a 6 cylinder engine or a V4 or a V2. And when they start taking cylinders out of the engine, the heart becomes weaker and weaker. You end up with a lot of problems including heart failure and sudden death.