In situ 3D visualization of the human cardiac conduction system revealed that changing cardiac inclination from standing to lying shifts the sinus node to the right outer position and the atrioventricular axis horizontally.
Observational (n=23)
The first in situ 3D visualization of the human cardiac conduction system reveals its anatomical transformation during positional changes and updates the topographical understanding of the bundle of His and bundle branches.
Current advanced imaging modalities with applied tracing and processing techniques provide excellent visualization of almost all human internal structures in situ; however, the actual 3D internal arrangement of the human cardiac conduction system (CCS) is still unknown. This study is the first to document the successful 3D visualization of the CCS from the sinus node to the bundle branches within the human body, based on our specialized physical micro-dissection and its CT imaging. The 3D CCS transformation by cardiac inclination changes from the standing to the lying position is also provided. Both actual dissection and its CT image-based simulation identified that when the cardiac inclination changed from standing to lying, the sinus node shifted from the dorso-superior to the right outer position and the atrioventricular conduction axis changed from a vertical to a leftward horizontal position. In situ localization of the human CCS provides accurate anatomical localization with morphometric data, and it indicates the useful correlation between heart inclination and CCS rotation axes for predicting the variable and invisible human CCS in the living body. Advances in future imaging modalities and methodology are essential for further accurate in situ 3D CCS visualization.
Kawashima et al. (Wed,) conducted a observational in Normal elderly human hearts (cadavers) (n=23). Physical micro-dissection combined with virtual CT dissection was evaluated on 3D visualization and morphometric data of the human cardiac conduction system. In situ 3D visualization of the human cardiac conduction system revealed that changing cardiac inclination from standing to lying shifts the sinus node to the right outer position and the atrioventricular axis horizontally.