Snipping the verve may stop 'flight-or-fight' stress response

What do sweaty palms and abnormal heart rhythms have in common? Both can be initiated by the nervous system during an adrenaline-driven "flight-or-fight" stress reaction, when the body senses danger.

Hyperhidrosis, an abnormal flight-or-fight response of the sympathetic nervous system that causes excessively sweaty palms may also contribute to problems like dangerous irregular rhythms from the lower chambers of the heart, known as ventricular arrhythmias.

UCLA cardiologists have now found that surgery to snip nerves associated with the sympathetic nervous system on both the left and right sides of the chest may be helpful in stopping dangerous, incessant ventricular arrhythmias — known as an "electrical storm" — when other treatment methods have failed. This same type of surgery has been used for years to alleviate hyperhidrosis.

The UCLA team's findings are reported in the Dec. 27–Jan. 3 issue of the Journal of the American College of Cardiology. The study is one of the first to assess the impact of bilateral cardiac sympathetic denervation (BCSD), surgery on both sides of the heart, to control arrhythmias. The research builds on previous work at UCLA in which a similar procedure was performed only on the left side. But for some patients to obtain relief, the researchers said, it must be done bilaterally. 

http://newsroom.ucla.edu/releases/snipping-key-nerves-may-help-life-220281 

5 (11%) thermoregulation difficulties, 4 (9%) a sensation of left arm paresthesia, and 3 (7%) sympathetic flight/fright response loss

Patients with LQTS (N=40) and catecholaminergic polymorphic ventricular tachycardia (N=7) underwent video-assisted thoracoscopic left cardiac sympathetic denervation, with a median follow-up of 29 months (range, 1-67 months). Clinical records were reviewed; 44 patients completed a telephone survey. Of 47 patients (53%), 25 were preoperatively symptomatic (15 syncope, 7 near-drowning, and 3 resuscitated sudden death). Indications for left cardiac sympathetic denervation included β-blocker intolerance (15; 32%) or nonadherence (10; 21%) and disease factors (18; 38%; catecholaminergic polymorphic ventricular tachycardia [6], near-drowning [2], exertional syncope [1], symptoms on therapy [2], LQT3 [1], QTc>520 ms [6]). Other indications were competitive sports participation (2), family history of sudden death (1), and other (1). Median QTc did not change among patients with LQTS (461±60 to 476±54 ms; P=0.49). Side effects were reported by 42 of 44 (95%). Twenty-nine patients (66%) reported dryness on left side, 26 (59%) a Harlequin-type (unilateral) facial flush, 24 (55%) contralateral hyperhidrosis, 17 (39%) differential hand temperatures, 5 (11%) permanent and 4 (9%) transient ptosis, 5 (11%) thermoregulation difficulties, 4 (9%) a sensation of left arm paresthesia, and 3 (7%) sympathetic flight/fright response loss. 

Circ Arrhythm Electrophysiol. 2015 Oct;8(5):1151-8. doi: 10.1161/CIRCEP.115.003159. Epub 2015 Jul 29.

Physical and Psychological Consequences of Left Cardiac Sympathetic Denervation in Long-QT Syndrome and Catecholaminergic Polymorphic Ventricular Tachycardia.

http://www.ncbi.nlm.nih.gov/pubmed/26224781

Endoscopic view of the right hemithorax:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2749196/figure/F0003/

Sympathectomy - a neurocardiologic disorder

Bilateral thoracic sympathectomies or sympathotomies are done for refractory palmar hyperhidrosis [85–87]. Iontophoresis, botulinum toxin injection, and glycopyrrolate cream are alternatives. Because sweating is mediated mainly by sympathetic cholinergic fibers, autonomic neurosurgery is usually effective; however, a variety of expected and unexpected consequences can result, including ectopic (e.g., plantar) hyperhidrosis, gustatory sweating, Horner syndrome, and decreased heart rate responses to exercise. The latter seems to be related to partial cardiac denervation [88]. Anecdotally, fatigue, altered mood, blunted emotion, and decreased ability to concentrate can develop after bilateral thoracic sympathectomies. 

β-Adrenoceptor blockers are a mainstay of treatment for CPVT. An automated defibrillator may have to be implanted. Treatment for CPVT also includes left sympathectomy. Such treatment leaves open the theoretical possibilities of denervation supersensitivity of cardiac adrenoceptors and compensatory activation of the adrenomedullary hormonal system; however, plasma levels of catecholamines have not been assessed in CPVT with or without therapeutic cardiac denervation.

Table 1. Neurocardiologic disorders that feature abnormal catecholaminergic function

Disorders where abnormal catecholaminergic function is etiologic Hypofunctional states without central neurodegeneration
Acute, primary
Neurocardiogenic syncope Spinal cord transection Acute pandysautonomia Sympathectomy
Acute, secondary
Drug-related (e.g., alcohol, tricyclic antidepressant, chemotherapy, opiate, barbiturates, benzodiazepines, sympatholytics, general anesthesia)
Seizures
Guillain–Barre syndrome Alcohol

Chronic, primary

Pure autonomic failure
Horner's syndrome
Familial dysautonomia
Carotid sinus syncope

Adie's syndrome Dopamine-β-hydroxylase deficiency
Sympathectomy 

http://onlinelibrary.wiley.com/doi/10.1111/j.1755-5922.2010.00244.x/full

https://archive.is/UMW1w

the clinical results of both surgical and neurolityc sympathectomy are uncertain

Blood diverted from muscle to skin after sympathectomy

 

However, the clinical results of both surgical and neurolityc sympathectomy are uncertain. Indeed these procedures lead to a redistribution of the blood flow in the lower limbs from the muscle to the skin, with a concomitant fall of the regional resistance, mainly in undamaged vessels. The blood flow will be diverted into this part of the vascular tree, so that a "stealing" of the blood flow may occur.

Vito A. Peduto, Giancarlo Boero, Antonio Marchi, Riccardo Tani

Bilateral extensive skin necrosis of the lower limbs following prolonged epidural blockade

Anaesthesia 1976; 31: 1068-75.

sympathectomy created imbalance of autonomic activity and functional changes of the intrathoracic organs

Surgical thoracic sympathectomy such as ESD (endoscopic thoracic sympathectic denervation) or heart transplantation can result in an imbalance between the sympathetic and parasympathetic activities and result in functional changes in the intrathoracic organs.

Therefore, the procedures affecting sympathetic nerve functions, such as epidural anesthesia, ESD, and heart transplantation, may cause an imbalance between sympathetic and parasympathetic activities (1, 6, 16, 17). Recently, it has been reported that ESD results in functional changes of the intrathoracic organs.


In conclusion, our study demonstrated that ESD adversely affected lung function early after surgery and the BHR was affected by an imbalance of autonomic activity created by bilateral ESD in patients with primary focal hyperhidrosis.
Journal of Asthma, 46:276–279, 2009
http://informahealthcare.com/doi/abs/10.1080/02770900802660949

Sympathectomy at the level of the T2 ganglion leads to decreased negative feedback to the hypothalamus

Compensatory sweating was originally thought to be a mechanism of excessive sweating (in an anatomical region with an intact sympathetic nervous system) to maintain a constant rate of total sweat secretion.90 However, this theory was not confirmed by other studies, demonstrating that compensatory sweating represented a reflex action by an altered feedback mechanism at the level of the hypothalamus which is dependent on the level at which sympathetic denervation occurs. Sympathectomy at the level of the T2 ganglion leads to decreased negative feedback to the hypothalamus. When performing a sympathectomy at a lower level, the negative feedback to the hypothalamus is less inhibited, leading to a decrease in compensatory sweating. Chou et al.91 have proposed the term ‘reflex sweating’ to replace compensatory sweating. Other side effects described in a review article by Dumont89 are gustatory sweating, cardiac effects, phantom sweating, lung function changes, dry hands and altered taste. Besides these side effects there are significant risks of complications during and after surgery (arterial or venous vascular injury, pneumothorax, infection, Horner syndrome etc.).

JEADV 2012, 26, 1–8 Journal of the European Academy of Dermatology and Venereology