During the past two years, we have been investigating the anatomy and physiology of the cardiac venous bed of dogs and have been studying the technique and value of the Beck II operation.1
Early in our studies, it became apparent that exposure of the dorsal aspect of the heart through standard approaches was quite a difficult feat. Initially, the dog was placed in the supine position and a right or left lateral transthoracic approach to the mediastinum and heart was employed, but the exposure was not satisfactory. Particularly annoying and embarrassing were the cardiac irregularities produced by either manual or suture traction upon the heart, for these frequently resulted in ventricular fibrillation and death.
Because of these two major problems—namely, (a) poor exposure of the coronary sinus and (b) the traction which had to be exerted upon the heart—we abandoned the supine position in favor of the prone