The surgical anatomy of the sinoatrial node.

The sinoatrial nodes (SAN) were observed, dissected, and measured on 95 adults and 30 child hearts under a dissection microscope. The majority of the SANs in adults are characterized by their pale color, firm consistency, and the location in relation to the penetration of the SAN artery, and they can be located in the superior part of the terminal sulcus. The SANs in children, however, are not easily discerned. The variation of the apex of the right auricular crest and the notch in the superior part of the terminal sulcus have been described, and the present authors suggested that the trigone of the SAN could be used as an important landmark to identify the SAN. The surface features on the SAN, its relationship to the surrounding myocardium and its surgical significance during operation are further discussed.