BY PATRICIA ANSTETT, FREE PRESS MEDICAL WRITER -- Eight months into an unprecedented plan to treat patients with heart attack symptoms more quickly, the Detroit Medical Center has shaved waiting times to 47 minutes, half what it takes at most U.S. hospitals. Cardio Team One started in March and cut waiting times by paying overtime to have senior cardiologists and three other members of the angioplasty team sleep in on a rotating schedule so that Harper University Hospital always has experienced staff available to perform emergency angioplasty, a minimally invasive procedure to open blocked arteries. It is the only program of its kind in the nation, according to the hospital corporation and experts in the field.