At their peak, panic attack symptoms are so severe and frightening that people often mistake them for signs of a heart attack and rush to the hospital. Although it is unclear whether the attacks themselves endanger the heart, those who experience them may be at higher risk of cardiovascular disease, says Jordan Smoller of Harvard University. In a recent study led by Smoller, researchers found that postmenopausal women who reported having a panic attack within six months of the study were four times as likely as other older women to have a heart attack or cardiac-related death during the next five years.