Origin and cervico-thoracic connections of the cardiac nerves in human fetuses.

MAILÉN GONZÁLEZ; SOFÍA PIVIDORI; FLORENCIA NICORA; TOMÁS MARTIN; VERENA FRANCO RIVEROS; BRUNO BUCHHOLZ

Estambul

Congreso; XX Congress. International Federation of Associations of Anatomists.; 2022

International Federation of Associations of Anatomists

Objectives:The aim was to deepen the knowledge of the human fetal extrinsic cardiacnervous system by the systematization of the origin and formation of thecardiac nerves, branches, and ganglia and its sympathetic/parasympatheticconnections. Methods:A detailed submacroscopic dissection of the cervical and thoracic region wasperformed in fifty sides from twenty-five human fetuses.Results:Cardiacaccessory ganglia that laid on a cardiac nerve or in the conjunction of two ormore (up to four) nerves before entering the mediastinal cardiac plexus wereobserved in 10 sides. Sympathetic cardiac nerves were individually variable andinconstant, except the superior cardiac nerve. In contrast, the parasympatheticcardiac branches appeared grossly to be more constant and invariable, althoughthe individual cardiac branches varied in number and position of origins. Eachsympathetic nerve or parasympathetic branch can be single or multiple (up tosix) and each of these individual nerves can be originated from the sympathetictrunk or the vagus nerve by one, two or three roots. Sympathetic nerves arosefrom cervical-thoracic ganglia or the interganglionic segment of thesympathetic trunk. There were connections outside the cardiac plexus, somecardiac nerves were linked to other cardiac nerves, and some others were linkedto non-cardiac nerves. Commoncardiac nerve trunks were more frequently observed on the right side (76%) thanthe left side (16%).Conclusions:The origin, frequency and connections of cardiac nerves/branches are highlyvariable. Detailed knowledge of the normal neuroanatomy of the heart could beuseful during cardiac neuromodulation.