1.) An unopposed vagal tone secondary to sympathectomy. This sympathectomy occurs 2-6 dermatomes higher than sensory block, so that a sensory block of T6 can conceivably inhibit all of the sympathetic innervation to the heart.
2.) The Bezold-Jarisch reflex – which may be widely under appreciated phenomenon. You’ll be surprised how many clinicians are not well versed in this essential physiology.
Sympathectomy → reductions in venous tone → profound decreased venous return. This activates mechanoreceptors embedded within the walls of the myocardium → stimulating vagal afferents → vasomotor center of medulla → increased vagal tone to the heart, thus slowing or stopping the heart entirely to allow enough filling time to generate an effective stroke volume.
http://allnurses.com/certified-registered-nurse/sympathectomies-and-atropine-124910.html
"Sympathectomy is a technique about which we have limited knowledge, applied to disorders about which we have little understanding." Associate Professor Robert Boas, Faculty of Pain Medicine of the Australasian College of Anaesthetists and the Royal College of Anaesthetists, The Journal of Pain, Vol 1, No 4 (Winter), 2000: pp 258-260
The amount of compensatory sweating depends on the patient, the damage that the white rami communicans incurs, and the amount of cell body reorganization in the spinal cord after surgery.
Other potential complications include inadequate resection of the ganglia, gustatory sweating, pneumothorax, cardiac dysfunction, post-operative pain, and finally Horner’s syndrome secondary to resection of the stellate ganglion.
www.ubcmj.com/pdf/ubcmj_2_1_2010_24-29.pdf
After severing the cervical sympathetic trunk, the cells of the cervical sympathetic ganglion undergo transneuronic degeneration
After severing the sympathetic trunk, the cells of its origin undergo complete disintegration within a year.
http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0442.1967.tb00255.x/abstract
Other potential complications include inadequate resection of the ganglia, gustatory sweating, pneumothorax, cardiac dysfunction, post-operative pain, and finally Horner’s syndrome secondary to resection of the stellate ganglion.
www.ubcmj.com/pdf/ubcmj_2_1_2010_24-29.pdf
After severing the cervical sympathetic trunk, the cells of the cervical sympathetic ganglion undergo transneuronic degeneration
After severing the sympathetic trunk, the cells of its origin undergo complete disintegration within a year.
http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0442.1967.tb00255.x/abstract