If a patient has shortness of breath after cardiac stenting, the patient is considered to have heart failure. After the symptoms of heart failure are corrected and improved, it is likely that the symptoms of shortness of breath will be improved in a week or so, but it is possible that the symptoms of heart failure will be triggered later, such as after lung infection or strenuous exercise, or after emotional excitement, and the symptoms may be repeated. In some people, shortness of breath is caused by the use of antiplatelet drugs like tigretol, which leads to shortness of breath and dyspnea, and after the drug is stopped and replaced by clopidogrel, the shortness of breath usually improves in about 2-3 years. In other people, shortness of breath may be due to the presence of lung infection at present, and after the lung infection is corrected and improved, the shortness of breath will also be corrected and improvement will usually occur in about a week.