The actual number of days of hospitalization depends on the specific condition and the specific test results. If it is only a simple cardiogram, the average number of days of hospitalization varies from 3 to 5 days. After hospitalization for cardiac angiography, the treatment process is as follows: on the first day of hospitalization, routine preoperative tests such as blood tests and chest radiographs are performed, except for contraindications. If the test results are normal, cardiac angiography will be performed on the second day. If the imaging result is normal, the patient can be discharged after 1 day of observation. However, if the angiogram reveals a more serious stenosis in the blood vessel, a stent needs to be placed intraoperatively, and postoperative anticoagulant medication needs to be applied. Generally, the hospital stay needs to be extended for about 1-2 weeks to observe whether there is postoperative bleeding, infection, arrhythmia, and prolonged clotting time. Pre-operative cardiac angiography-related examinations are indispensable, and once the examination reveals abnormal indicators, the original disease may have to be treated before cardiac angiography is done.