By Advocate.com Editors

Originally published on Advocate.com October 21 2009 9:00 AM ET

Everyone knows the tell-tale sign of a heart attack: severe chest pain, chief among the physical symptoms. But did you know it's also possible to have a “silent” -- but still very dangerous -- heart attack that goes virtually unnoticed? And, according to a new Duke University study, these cardiac events are more common than once thought.

Typically, doctors look for a sign of a previous heart attack called a “Q-wave” that is detected through an electrocardiogram. But the Duke researchers used a new, more sensitive technique called delayed-enhancement cardiovascular magnetic resonance, which can detect signs of a heart attack even electrocardiograms miss.

When the physicians screened 185 adults with coronary artery disease but no outward symptoms of a heart attack, they found that 35% had indeed suffered a “silent” attack. And heart attacks that left no Q-wave signature were found to be three times more common than those that were detectable through standard measurements.

Although the researchers aren't calling for widespread magnetic resonance testing of all adults, they say the test could be beneficial for people who have signs of cardiovascular disease or those at heightened risk for heart problems.