Dr. Lloyd Rudy, a pioneer of cardiac surgery, tells about two patients who came back to life after being declared dead in the operating room. In the first story, the patient described the operating room, the people in it and what they were doing while he was dead.
In the second story, the patient had uncontrollable bleeding. The doctor states that their efforts to stop the bleeding failed, but then a "presence" showed up in the room, which everyone felt and immediately the patient stopped bleeding.
Dr. Rudy confessed ignorance as to who or what the "presence" might be. If you're a regular follower of this blog, you might recognize the "presence" as the Holy Spirit, who sometimes heals the sick or even brings the dead back to life, just by showing up.