A new report from the Framingham Heart Study calls into question the health of 20 million Americans who have been diagnosed with some degree of mitral valve prolapse. As CBS News Correspondent John Roberts reports, this potentially serious heart condition may not be nearly as common as doctors once thought.
The first inkling Ed Siegel had that there was a problem with his heart came when he was a boy. In a common scenario, his doctor noticed a slight murmur.
"It became known as the phantom heart murmur because it would be found, and the next time I would go for some kind of test or even an electrocardiogram, they couldn't even find it," he says.
Siegel was eventually diagnosed with mitral valve prolapse, a condition in which one of the heart's valves becomes thickened and floppy, preventing proper closure. A murmur occurs in severe cases, when blood flows backward through the heart.
"It was felt to be one of the most common congenital heart abnormalities, ranging anywhere from five to 15 percent of the population," says Dr. Nieca Goldberg of Lenox Hill Hospital.
But a report in the New England Journal of Medicine states that because of poor diagnostic techniques, as many as 15 million Americans who were told they had mitral valve prolapse actually didn't.
It's also believed that the risks those people were told they faced - including stroke, heart failure and heart infections - were greatly exaggerated.
Study author Dr. Emelia Benjamin stresses the impact of this news.
"I think it's very important because hopefully it can allay the anxiety that many patients have had that they have been given a death sentence. or that they are going to go on and have these very serious complications," she says.
People with severe forms of the condition still face increased risk, so researchers recommend anyone with a previous diagnosis should check with their doctor about getting updated testing.