Almost half of all heart attacks cause no obvious symptoms, yet they can still be life-threatening, according to research on more than 9,000 middle aged men and women.

            The results are not surprising to Dr. Charles Porter, a cardiologist at The University of Kansas Hospital. In the video, he explains what the study shows about these so-called “silent heart attacks” versus classic heart attacks. He addresses whether an EKG should be a routine part of an exam, the difference between a silent heart attack and sudden cardiac death and why the risk of death from a silent heart attack is relatively low.