The sympathetic contributions to the cardiac plexus.

Area of Science:

• Anatomy
• Neurosurgery
• Cardiology

Background:

• Minimally invasive cardiac sympathetic denervation is increasingly used for intractable angina pectoris.
• Effective denervation requires a detailed understanding of cardiac innervation and its anatomical variations.

Purpose of the Study:

• To elucidate the cervical and thoracic sympathetic contributions to the cardiac plexus.
• To map the anatomical pathways of cardiac innervation for improved surgical denervation techniques.

Main Methods:

• Micro-dissection of cervical and thoracic sympathetic trunks in 21 fetuses and 8 adults (58 sides).
• Bilateral documentation of superior, middle, and cervico-thoracic ganglia and their cardiac rami.
• Tracing of all identified cardiac rami to the deep cardiac plexus.

Main Results:

• The superior cervical ganglion gave rise to the superior cervical cardiac ramus in 53% of specimens.
• The middle cervical ganglion (81% incidence) supplied the middle cervical cardiac ramus in 88% of cases.
• The cervico-thoracic ganglion (85% incidence) gave rise to the cervico-thoracic cardiac ramus in 84% of specimens; four thoracic cardiac rami originated from T2-T6.
• All identified rami consistently connected to the deep cardiac plexus.

Conclusions:

• Variations in cervical ganglia and cardiac rami patterns do not seem to impact the success of limited sympathectomy for angina pain relief.
• Further research is needed to fully understand the complexity of cardiac pain pathways and neuronal pathways involved.