Dr. Clarence Dennis led the team at the University of Minnesota Medical Center that on April 5, 1951, conducted the first human operation involving open cardiotomy with temporary mechanical takeover of both heart and lung functions. The patient did not survive due to an unexpected complex congenital heart defect. One member of the team was Dr. Russell M. Nelson, who later became president of The Church of Jesus Christ of Latter-day Saints and who performed the first open heart surgery in Utah.