ABSTRACT
The effects of qi-tonics and blood-activating decoction on acute myocardial infarction and ischemia-reperfusion induced arrhythmias were studied in anaesthetized open chest SD rats. Three days before coronary artery occlusion, the qi-tonics and blood-activating decoction was perfused into the stomach of the rats in the experimental group (10 ml/kg weight) once a day, and 4d later, the coronary artery was occluded in anaesthetized open chest rats. The results demonstrated that qi-tonics and blood-activating decoction could reduce significantly the incidence and severity of arrhythmias caused by myocardial infarction and ischemia-reperfusion. The qi-tonics and blood-activating decoction could decrease the amount of the superoxide anion radicals (O2-) produced in the alkaline dimethyl sulfoxide (DMSO) system measured by electron paramagnetic resonance (EPR) at low temperature. The effect of qi-tonics and blood-activating decoction on O2-may be one of the mechanisms for its antiarrhythmic effect during reperfusion.