Vivien T. Thomas. In 1944, Hopkins' surgery chief, Alfred Blalock, successfully operated on the heart of a 9-pound child. Medical experts believed cardiac surgery was impossible. As Blalock prepared to make his historic incision, he looked around the operating room and asked, "Where's Vivien?" Blalock would not begin until Thomas, stationed on a stool behind his right shoulder, was there to guide Blalock through procedures.