Targeted stellate decentralization: Implications for sympathetic control of ventricular electrophysiology.
BACKGROUND
Selective bilateral cervicothoracic sympathectomy has proven to be effective for managing ventricular arrhythmias in the setting of structural heart disease. In the procedure currently used, the caudal portions of both stellate ganglia along with thoracic chain ganglia down to T4 ganglia are removed.


OBJECTIVE
The purpose of this study was to define the relative contributions of the T1-T2 and T3-T4 paravertebral ganglia in modulating ventricular electrical function.


METHODS
In anesthetized vagotomized porcine subjects (n = 8), the heart was exposed via sternotomy along with right and left paravertebral sympathetic ganglia to the T4 level. A 56-electrode epicardial sock was placed over both ventricles to assess epicardial activation-recovery intervals (ARIs) in response to individually stimulating right and left stellate vs T3 paravertebral ganglia. Responses to T3 stimuli were repeated after surgical removal of the caudal portions of stellate ganglia and T2 bilaterally.


RESULTS
In intact preparations, stellate ganglion vs T3 stimuli (4 Hz, 4-ms duration) were titrated to produce equivalent decreases in global ventricular ARIs (right side: 85 ± 6 ms vs 55 ± 10 ms; left side: 24 ± 3 ms vs 17 ± 7 ms). Threshold of stimulus intensity applied to T3 ganglia to achieve threshold was 3 times that of T1 threshold. ARIs in unstimulated states were unaffected by bilateral stellate-T2 ganglion removal. After acute decentralization, T3 stimulation failed to change ARIs.


CONCLUSIONS
Preganglionic sympathetic efferents arising from the T1-T4 spinal cord that project to the heart transit through stellate ganglia via the paravertebral chain. Thus, T1-T2 surgical excision is sufficient to functionally interrupt central control of peripheral sympathetic efferent activity.
Cardiac Arrhythmia Center & Neurocardiology Research Center, UCLA David Geffen School of Medicine, Los Angeles, California.
Una
U
Buckley
Cardiac Arrhythmia Center & Neurocardiology Research Center, UCLA David Geffen School of Medicine, Los Angeles, California.
Kentaro
K
Yamakawa
Cardiac Arrhythmia Center & Neurocardiology Research Center, UCLA David Geffen School of Medicine, Los Angeles, California.
Tatsuo
T
Takamiya
Cardiac Arrhythmia Center & Neurocardiology Research Center, UCLA David Geffen School of Medicine, Los Angeles, California.
J
J
Andrew Armour
Cardiac Arrhythmia Center & Neurocardiology Research Center, UCLA David Geffen School of Medicine, Los Angeles, California.
Kalyanam
K
Shivkumar
Cardiac Arrhythmia Center & Neurocardiology Research Center, UCLA David Geffen School of Medicine, Los Angeles, California. Electronic address: jardell@mednet.ucla.edu.
Jeffrey L
JL
Ardell
D000818:Animals; D004195:Disease Models, Animal; D004558:Electric Stimulation / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac; D055724:Electrophysiological Phenomena; D015171:Ganglionectomy / Q000379:methods*; D006352:Heart Ventricles / Q000294:innervation / Q000503:physiopathology; D008297:Male; D013233:Stellate Ganglion / Q000502:physiology / Q000503:physiopathology / Q000601:surgery; D013552:Swine
Stellate ganglion; Sudden death; Sympathectomy; Sympathetic efferent neurons; Ventricular arrhythmia; Ventricular electrical indices