FRIDAY, May 31, 2002 (HealthDayNews) -- You know the old saying that what you don't know can't hurt you, but you might want to rethink that if you've had a heart attack.
A recent survey reveals that most heart attack survivors don't know if they're at risk for a dangerous heart rhythm disorder that causes sudden cardiac death (SCD) and kills more than 400,000 Americans each year.
The survey was done by the North American Society of Pacing and Electrophysiology (NASPE), and presented at their annual meeting earlier this month.
The online survey of 160 heart attack survivors found that less than half of them knew their ejection factor (EF), which is the leading predictor of the risk of SCD.
EF is the proportion, or fraction, of blood pumped from the heart with each beat. Your EF can be easily measured by echocardiography -- a simple, painless ultrasound exam of the heart -- or other tests.
A normal EF is 55 percent or higher. People with an EF of 40 percent or lower should be tested further to see if they have the abnormal heart rhythm that puts them at high risk for SCD.
More information
The ejection factor is also known as the heart ejection fraction. This diagram from the Colorado Health Site explains how blood is pumped through the heart.
