The heart rate of 40~50 beats/min is considered as bradycardia. In addition to causative treatment, if symptoms occur, atropine and isoproterenol can be applied to increase the heart rate under the guidance of doctor. 1. Atropine: it is an anticholinergic drug and belongs to M-blocker, which is suitable for sinus bradycardia and can stimulate sympathetic nerves to increase heart rate. 2. isoproterenol: the drug can excite the heart receptor, strengthen the contraction ability of the heart muscle, make the heart rate faster, at the same time have the effect of increasing blood pressure, should be used under the guidance of a doctor. Bradycardia in addition to the use of drugs to improve, part of the drug effect is poor, or even more serious patients can be considered through the pacemaker implantation for treatment, it is recommended that timely medical treatment.