In the preceding article, Drs Svensson and Mihaljevic 1 remind us of a forgotten milestone in the history of cardiac surgery. The 1950s were monumental in the origin of techniques for direct vision intracardiac repairs. The first successful application of a heart-lung machine to repair a heart defect was reported by Gibbon in 1953. 2 Lillehei was the first to successfully close a ventricular septal defect on March 26, 1954, using cross-circulation with a parent for support. 3 Kirklin was the first to successfully close a ventricular septal defect using a modification of Gibbon's pump on March 25, 1955. 4 Interestingly, in the year 1955 all the open-heart surgery performed anywhere in the world was performed in Minnesota, either by Kirklin or by Lillehei. To the best of our knowledge, neither surgeon "stopped the heart" to perform the repairs.By the end of 1955, other surgeons, learning from what was happening in Minnesota, began to develop and apply their own adaptations to permit open heart surgery at other centers around the world. Among those centers was the Cleveland Clinic with Donald Effler as surgeon. The Cleveland Clinic had the advantage of Dr Willem Kolff, who was instrumental in developing a membrane oxygenator, a key component of the Cleveland Clinic heart-lung machine. 5 Kolff also recognized the contribution of Melrose, who determined that the heart could be arrested with aortic occlusion and instillation of a solution of blood and potassium citrate. 6 The advantage of a "stopped heart" was improved visualization, less blood in the operative field, and prevention of air embolism. Effler and Groves tested this technique