Wenxin-Keli (WXKL) is a Chinese herbal compound reported to be of benefit in the 
treatment of cardiac arrhythmia, cardiac inflammation, and heart failure. 
Amiodarone is a noncompetitive inhibitor of the α - and β -adrenergic receptors 
and prevents calcium influx in the slow-response cells of the sinoatrial and 
atrioventricular nodes. Overexpression of Ca(2+)/calmodulin-dependent protein 
kinase II (CaMKII) in transgenic mice results in heart failure and arrhythmias. 
We hypothesised that administration of WXKL and amiodarone can reduce the 
incidence of arrhythmias by regulating CaMKII signal transduction. A total of 
100 healthy Sprague Dawley rats were used in the study. The rats were randomly 
divided into four groups (a sham group, a myocardial infarction (MI) group, a 
WXKL-treated group, and an amiodarone-treated group). A myocardial infarction 
model was established in these rats by ligating the left anterior descending 
coronary artery for 4 weeks. Western blotting was used to assess CaMKII, 
p-CaMKII (Thr-286), PLB, p-PLB (Thr-17), RYR2, and FK binding protein 12.6 
(FKBP12.6) levels. The Ca(2+) content in the sarcoplasmic reticulum (SR) and the 
calcium transient amplitude were studied by confocal imaging using the 
fluorescent indicator Fura-4. In conclusion, WXKL may inhibit heart failure and 
cardiac arrhythmias by regulating the CaMKII signal transduction pathway similar 
to amiodarone.