The first successful operations on the mitral valves, published in a paper of monograph length. As Surgeon-in-Chief of Peter Bent Brigham Hospital, under whom Beck, Cutler, and Levine worked, Harvey Cushing reported, "Dr. Beck has largely been engaged during the fall semester assisting Dr. Cutler in his experiments concerned with the future operative surgery of cardiac derangements. It is to the great credit of the Brigham Hospital that the first successful operation for mitral stenosis to be recorded has been the outcome of this work. Unless all signs fail, were are on the eve of a new surgical specialty of the great promise- a specialty dealing with the chronic disorders of the heart" (Cushing, 10th Annual Report of the Surgeon-in-Chief [1924)].