But did you know that half of all heart attack victims have absolutely no advance warning symptoms? That's right. The first heart disease symptom they experience is the actual heart attack.

And did you know there's a little-known risk factor that doesn't even show up on any of the traditional tests? It doesn't show up on any blood tests, you can't detect it with a stethoscope or EKG. And it doesn't show up on any high-tech medical scans, either.

So what is the hidden heart attack trigger? Several university studies have found that people who interrupt conversations are at a greater risk for heart problems. In fact, one study at Duke University found that people who interrupt are up to seven times more likely to get heart disease!

Why is this so? The researchers theorize that people who interrupt are excessively competitive and controlling - two hallmarks of the worst “Type A” personalities.

Now, here the amazing part: These high-risk people can lower their risk without totally altering their personalities - and without any drugs, exercise or dietary changes. All they have to do is practice being good listeners. In one study, the test subjects focused on being silent while others talked. Result: They lowered both their blood pressure and their stress hormone levels.