Partial cardiac sympathetic denervation after bilateral thoracic sympathectomy in humans.
BACKGROUND
Upper thoracic sympathectomy is used to treat several disorders. Sympathetic nerve fibers emanating from thoracic ganglia innervate the heart. Whether unilateral or bilateral upper thoracic sympathectomy affects cardiac sympathetic innervation in humans in vivo has been unclear.


OBJECTIVE
The purpose of this study was to assess whether thoracic sympathectomy decreases cardiac sympathetic innervation, as indicated by positron emission tomographic scanning after intravenous injection of the sympathoneural imaging agent 6-[18F]fluorodopamine.


METHODS
Nine patients with previous upper thoracic sympathectomies (four right-sided, one left-sided, four bilateral) underwent thoracic 6-[18F]fluorodopamine scanning between 1 and 2 hours after injection of the imaging agent. In each case, a low rate of entry of norepinephrine into the arm venous drainage (norepinephrine spillover) verified upper limb sympathectomy. Data were compared with those from the interventricular septum of patients with cardiac sympathetic denervation associated with pure autonomic failure and from normal volunteers.


RESULTS
All four patients with bilateral sympathectomy had low septal myocardial 6-[18F]fluorodopamine-derived radioactivity (2,673 +/- 92 nCi-kg/cc-mCi at an average of 89 minutes after injection) compared with normal volunteers (3,634 +/- 311 nCi-kg/cc-mCi at 83 minutes, N = 22, P = .007) and higher radioactivity than in patients with pure autonomic failure (1,320 +/- 300 nCi-kg/cc-mCi at 83 minutes, N = 7, P = .003). Patients with unilateral sympathectomy had normal 6-[18F]fluorodopamine-derived radioactivity (3,971 +/- 337 nCi-kg/cc-mCi at 87 minutes).


CONCLUSIONS
Bilateral upper thoracic sympathectomy partly decreases cardiac sympathetic innervation density.
Moak
Jeffrey P
JP
Children's National Medical Center, Washington, DC, USA. moakj@ ninds.nih.gov
Eldadah
Basil
B
Holmes
Courtney
C
Pechnik
Sandra
S
Goldstein
David S
DS
D000704:Analysis of Variance; D004298:Dopamine; D005462:Fluorine Radioisotopes; D006321:Heart / Q000000981:diagnostic imaging / Q000294:innervation*; D006801:Humans; D013562:Sympathectomy / Q000009:adverse effects*; D014055:Tomography, Emission-Computed
D005462:Fluorine Radioisotopes; D004298:Dopamine