Bradycardia, chest tightness and shortness of breath may be caused by hypothyroidism, sinus node lesions, and adverse drug reactions. It can be treated with medication or cardiac pacing as prescribed by the doctor. 1. Hypothyroidism: Hypothyroidism leads to a low metabolic state, resulting in bradycardia and shortness of breath. It can be treated by supplemental thyroxine, and can be combined with the use of atropine and other drugs to increase the heart rate, the specific use of drugs need to follow the doctor’s instructions. 2. Sinus node lesions: normal sinus rhythm originates in the sinus node, when the sinus node fibrosis and other lesions can cause bradycardia, followed by chest tightness and shortness of breath and other symptoms of myocardial ischemia. It can be treated with drugs such as atropine or isoprenaline, and is contraindicated in patients with coronary artery disease, myocarditis, tachycardia, and angina pectoris. Serious patients should consider cardiac pacing therapy. 3. Adverse drug reactions: when taking amiodarone, propranolol and other drugs, the adverse reaction of bradycardia will occur, and when the heart rate is seriously reduced, it will cause chest tightness, shortness of breath and other symptoms of myocardial ischemia. Should go to the hospital in time, under the guidance of the doctor to adjust the drug or stop the drug. The symptoms of bradycardia, chest tightness and shortness of breath should go to the hospital in a timely manner, after clarifying the cause of the disease under the guidance of the doctor to carry out regular treatment.