Wenxin Keli suppresses atrial substrate remodelling after epicardial ganglionic plexi ablation.

Abstract

Background: The chronic effects of ganglionic plexi (GP) ablation on atrial fibrillation (AF) inducibility have not been elucidated.

Objective: To investigate the effect of Wenxin Keli (WK) on the inducibility of AF and atrial substrate remodelling after epicardial GP ablation.

Methods: Twenty dogs were randomly divided into a sham-operated group, a GP ablation group and a WK-treated group. All animals underwent a left thoracotomy at the fourth intercostal space. AF inducibility was assessed by burst rapid pacing at the right atrium. Both the GP ablation group and the WK-treated group received four major GP ablations. In the WK-treated group, dogs were treated with oral WK once per day, and all animals were allowed to recover for eight weeks, after which AF inducibility and AF duration were measured again.

Results: After eight weeks of WK treatment, AF inducibility was lower than in the GP ablation group, and was similar to that of the sham-operated group. Compared with the sham-operated group, the levels of atrial natriuretic peptide (ANP), tumour necrosis factor-alpha (TNF-α) and interleukin (IL)-6 in right atrial tissues were increased in GP ablation group (143.6±33.7 pg/mg versus 206.2±41.4 pg/mg, P=0.02; 75.3±12.1 pg/mg versus 141.3±64 pg/mg, P=0.03; and 175.1±42.5 pg/mg versus 351.7±101 pg/mg, P<0.01, respectively). There were no significant differences in levels of ANP, TNF-α and IL-6 in atrial tissues between the sham-operated group and WK treated group. Expression of connexin 43 in atrial tissues was increased after eight weeks of GP ablation, while WK administration inhibited connexin 43 remodelling.

Conclusions: Epicardial GP ablation can induce atrial substrate remodelling, including Cx43 upregulation and increased levels of ANP, TNF-α and IL-6. These changes may be suppressed by long-term oral WK administration.