ABSTRACT
The antibradycardia effect of extract of RAE [Radix Aconiti and Astragalus] on bradycardia animal models were evaluated. Bradycardia rat model was induced by amiodarone or propranolol, and sick sinus syndrome [SSS] rabbit model was induced by chemical stimulation on surface of sinus node. The heart rates of the animal models were calculated according to ECG recording. The value of sino-atrial conduction time [SACT] and correcting sinus node recovery time [CSNRT] of SSS rabbit model were measured by multi-channel physiological recorder. The blood flow of aorta and coronary the diabolic pressure of normal rat hearts in vitro were measured. Treatment with RAE could increase the heart rate of bradycardia animals induced by amiodarone, propranolol, or SSS rabbit model significantly. Treatment with RAE could decrease in the value of SACT and CSNRT of SSS rabbit model. Moreover, treatment with RAE could increase the blood flow of aorta and coronary and could decrease diabolic pressure of normal rat hearts in vitro. RAE has heart-rate-increasing effect, which might be related to its ameliorating the autorhythmicity of sinus node and improving the sino-atrial conductive function. Moreover, RAE could ameliorate cardiac blood supply and enhance cardiac function.