Increasing experience suggests that retrograde cardioplegia offers several benefits during cardiac reoperations. However, the need for dissection to allow caval snares for open coronary sinus intubation or to palpate the atrioventricular groove for transatrial coronary sinus intubation may disturb diseased vein grafts or require more dissection than necessary. Although antegrade-retrograde techniques can be used, antegrade cardioplegia risks atheromatous embolization from old vein grafts. To optimize delivery of cardioplegic solution, we designed and used "no touch" transatrial intubation of the coronary sinus for retrograde delivery of cardioplegic solution in 63 consecutive patients aged 20 to 87 years (mean 68 years) undergoing 36 redo coronary bypass operations, 7 combined redo coronary bypass/valve replacements, 6 redo aortic valve repairs/replacements, 6 redo mitral valve repairs/replacements, 4 redo double valve repairs/replacements, 2 redo triple valve repairs/replacements, and 2 redo composite aortic valve and arch replacements. "No touch" coronary sinus cannulation was achieved by minimally dissecting the aorta and high right atrium enough for two purse-string sutures. No attempt was made to dissect the junction of the inferior vena cava and atrioventricular groove if old vein grafts were present. The distal pressure line of the Gundry DLP RCSP retrograde cardioplegia cannula (DPL, Inc., Grand Rapids, Mich.) was connected to a transducer, flushed, and then introduced into the right atrium. The pressure tracing thus obtained was observed while the catheter was advanced, using its curved stylet, "blindly" without touching the heart, through the right atrium into the coronary sinus until a coronary sinus waveform was obtained (similar to floating a thermodilution catheter). The catheter's distal balloon was then inflated to occlude the coronary sinus momentarily. A rise in sinus pressure confirmed placement. If pressure did not rise, the cannula was usually in the right ventricle and was repositioned. All coronary sinuses were successfully intubated blindly. Bypass was then instituted, the aorta crossclamped, and the proximal aorta vented. Old vein grafts were cut at the aorta before retrograde cardioplegia was begun; atheromatous material was routinely flushed retrogradely from vein grafts. Only after arrest were hearts dissected as needed. Antegrade cardioplegia was not used. There were two (3%) deaths, both from hospital-acquired pneumonia, no perioperative myocardial infarctions, and no episodes of heart block. Inotropic agents were used in six of 63 patients (10%). We conclude that "no touch" transatrial retrograde cardioplegia offers optimal, simplified myocardial protection for cardiac reoperations, permits arrest of the heart before cardiac manipulations, and expands the use of retrograde cardioplegia by obviating cardiac dissection.