Huoxin Pill Ameliorates Atrial Fibrillation by Modulating Autonomic Nervous Balance and Electrical Conduction Heterogeneity: Insights From Systems Pharmacology and Experimental Validation.

Huoxin Pill (HXP), a traditional Chinese medicine for cardiovascular diseases, demonstrates clinically reported anti-atrial fibrillation (AF) effects, though its mechanisms remain unclear. To investigate these mechanisms, we established an acetylcholine-calcium chloride (ACh-CaCl2)-induced AF model in rats divided into control, AF, HXP (HXP-L: 3.33; HXP-M: 10; HXP-H: 30 mg/kg) and verapamil (25 mg/kg) groups. Following daily modelling, treatments were administered via gavage from Days 4 to 10. Electrocardiography (ECG) subsequently assessed AF susceptibility while echocardiography evaluated cardiac function. Systems pharmacology predicted HXP's targets/pathways for AF amelioration, with heart rate variability (HRV) and nerve activity recording examining autonomic balance. Electrical mapping quantified activation time (AT), conduction velocity (CV), conduction dispersion and effective refractory period (ERP) in isolated hearts. Results demonstrated that the AF group exhibited increased AF incidence/duration and decreased left ventricular ejection fraction/fractional shortening (LVEF/LVFS). Systems pharmacology revealed significant enrichment in cardiovascular pathways (including AF), while HRV and nerve recording indicated autonomic imbalance. Isolated AF hearts showed prolonged AT, slowed CV, increased conduction dispersion and shortened ERP. HXP significantly ameliorated these alterations. In conclusion, these findings suggest that HXP improves ACh-CaCl2-induced AF, potentially through modulating autonomic nervous balance and atrial electrical conduction heterogeneity.