There are several reasons that stellate ganglion block affects the cardiovascular system. Stellate ganglion block will initially affect both the sympathetic and parasympathetic nervous systems based on the degree of block. The intensity of right stellate ganglion blockage of the sympathetic and parasympathetic nervous system will result in heart rate changes and altered activity of the sympathetic and parasympathetic nervous system. Efferent sympathetic innervation from the right stellate ganglion is primarily distributed over the sinus node of the heart, and the influence of the autonomic nervous system and left stellate ganglion block should be assessed. Further, results will be affected by the health status of participants.
Although efferent sympathetic nerves from the stellate ganglion are primarily distributed over the heart, efferent sympathetic fibers from the 2nd to 5th thoracic ganglia affect the heart as well. Accordingly, the autonomic nervous system of the heart is not completely dependent on the stellate ganglia. The influence of the autonomic nervous system cannot be excluded as well. It is worth noting that the mepivacaine in the present study was a lower dosage than those used in other studies. Finally, the autonomic nervous system varies in a unique, autonomous manner, and it is therefore difficult to assess changes in patients in a uniform manner or just through the application of one or two indicators. Future studies should examine diverse methods for the assessment of autonomic nervous system function.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2872892/