THORACIC SYMPATHETIC CARDIAC NERVES IN MAN

The application of surgery involving extirpation of the inferior cervical sympathetic ganglions, particularly in the treatment of patients with diseases involving the blood vessels of the upper extremities, has revived interest in the anatomic relationships of the sympathetic cardiac nerves and necessitated a reinvestigation of the exact sources and distribution of these nerves. Although Valentin1described nerves that arise from the medial aspect of the second thoracic sympathetic ganglion in man, extend medianward and downward, and send some fibers into the cardiac plexus, the more recent accounts of the innervation of the heart in man and in lower mammals, with few exceptions, make no mention of cardiac nerves arising from the sympathetic trunks below the inferior cervical ganglion. According to the current textbook statements, the sympathetic innervation of the heart is mediated solely through the superior, middle and inferior sympathetic cardiac nerves, which arise from the superior, middle and