Sympathetic innervation of the anterior left ventricular wall by the right and left stellate ganglia

Abstract

Background: The sympathetic nervous system is thought to play a role in the genesis of ventricular tachyarrhythmias (VT). Left and added right cardiac sympathectomy have been shown to reduce the burden of arrhythmias in the setting of a VT storm. However, the contribution of the right stellate ganglion (RSG) and the left stellate ganglion (LSG) to the innervation of the anterior left ventricular (LV) wall is not well understood.

Objective: To evaluate the innervation of the anterior LV wall by the LSG and the RSG.

Methods: The heart and stellate ganglia were exposed via sternotomy in pigs with normal hearts (n = 8). A 20-electrode catheter was placed on the anterior LV wall to record activation recovery interval (ARI), a surrogate measure of action potential duration. A microdialysis catheter was inserted in a similar location to sample interstitial norepinephrine (NE) content. ARI and NE measurements were recorded at baseline and during LSG and RSG stimulation.

Results: LSG stimulation shortened ARI by 17.1% ± 10.5% (mean ± standard error), while RSG stimulation shortened ARI by 42.1% ± 15.7%, P = .04 (LSG vs RSG). LSG stimulation increased interstitial NE levels by 200% ± 65%, while RSG stimulation increased the NE content by 260% ± 40% (P = .012). LSG stimulation increased dispersion in ARI from 376.0 ± 83.7 ms(2) to 1242.5 ± 566 ms(2) (P = .03) and caused ventricular fibrillation in 2 pigs. During RSG stimulation, dispersion increased from 419 ± 65.8 to 474.8 ± 81 ms(2) (P = .4).

Conclusions: Both the LSG and the RSG provide significant innervation to the anterior LV wall as demonstrated by both ARI shortening and NE concentrations. LSG stimulation significantly increases ARI dispersion. This study provides mechanistic insight into the beneficial effects of left sympathectomy and the additional role of right sympathectomy in reducing arrhythmias in patients with anterior myocardial scars and VT storm.