Increased inflammation promotes ventricular arrhythmia through aggravating left stellate ganglion remodeling in a canine ischemia model.

BACKGROUND: Increased inflammation was found in the left stellate ganglion (LSG) in patients with malignant ventricular arrhythmia (VA). However, the role of inflammation in LSG remodeling is unknown. This study aimed to investigate whether exogenous interleukin-1β (IL-1β) could aggravate VA through regulating LSG remodeling.

METHODS: Twenty-four canines who received saline (Control, n=8), IL-1β injection into the LSG (n=8) or IL-1 receptor antagonist (IL-Ra) pre-injection plus IL-1β injection (n=8) were included. Ventricular electrophysiology parameters, heart rate variability (HRV), LSG activity were measured at different time points. VA was recorded for 60min after ischemia and then LSG tissues were collected for molecular detection.

RESULTS: Compared with the control group, IL-1β injection decreased the effective refractory period, action potential duration (APD)90 and increased the maximal slope of the restitution curve in normal hearts. Besides, the occurrence of VA was significantly increased in the IL-1β group. Additionally, IL-1β injection increased the sympathetic indices of HRV and LSG activity in normal and ischemic hearts. Mechanically, the mRNA expression of pro-inflammatory cytokines and protein expression of c-fos, nerve growth factor and neuropeptide Y in LSG were increased, whereas the expression of neuronal nitric oxide synthase was decreased in the IL-1β group. More importantly, all these effects induced by IL-1β were attenuated by IL-1Ra pre-injection.

CONCLUSION: Increased inflammation induced by IL-1β injection aggravates ischemia induced VA through regulating the neuronal remodeling of the LSG. Inflammation induced neuroplasticity may be a novel mechanism and therapeutic target for VA.