In order to assess the three-dimensional movement of the coronary arteries both during normal cardiac activity and after mechanical stabilization, a polypropylene black marker was placed in 10 pigs on the middle portion of the three main coronary branches. Marker motion was recorded for 10 s using two TV-digital cameras and was estimated with a precision of 50 microm. After stabilization with three different mechanical stabilizers (Medtronic, Genzyme, CTS-Guidant), a remnant coronary artery excursion of about 1.5-2.4 mm was found. There is a significant residual coronary artery motion after mechanical stabilization, which could affect the quality of anastomosis, especially in unfavourable situations.