Atrial Heterogeneous Autonomic Neural Remodeling in Rabbits with Experimental Atrial Fibrillation and the Effect of Intervention by Rosuvastatin.

The study aimed to observe the effects of pacing on the atrial effective refractory period (AERP), inducibility of atrial fibrillation (AF), and changes of atrial autonomic neural remodeling (ANR) by rosuvastatin intervention on the acute model of rapid-pacing-induced AF.

Thirty rabbits were randomly divided into a control group (C, n = 10), rapid-pacing group (P, n = 10), and rosuvastatin-intervention group (R, n = 10). AERP and inducibility of AF were measured for all groups. The sympathetic and parasympathetic nerves of left atrium, right atrium, and atrial septum labeled with tyrosine hydroxylase (TH) and choline acetyl transferase (ChAT) were detected by immunohistochemistry and Western blot.

The AERP in group R was prolonged, and AF could not be induced as easily (P < 0.05). Immunohistochemistry showed that the densities and heterogeneity of TH and ChAT positive nerves of the atrium in group P were significantly higher than those in group C (ranked as right atrium > atrial septum > left atrium), whereas those in group R were decreased (P < 0.05). Western blot showed that TH and ChAT protein expression in group P was significantly increased compared with group C, but decreased in group R (P < 0.05).

Persistent rapid atrial pacing can lead to heterogeneous ANR in different parts of the rabbit atrium and may cause AF, which can be reversed by rosuvastatin. The inhibitory function of rosuvastatin may be associated with its role in reversing atrial ANR.