CIRCULATORY SYSTEM–According to lower-extremity sources, a blood clot two to three times larger than necessary to cause a heart attack has broken loose from your femoral artery and is migrating up your leg at this very moment. "In light of the size of this clot," your doctor said, "calling 911 would only waste city resources." Your doctor recommended that you lie down near the front door so the coroner's office can more easily remove your body from your home.