Cardiography is required in the presence of unexplained chest pain, arrhythmia, and cardiac insufficiency. Cardiac angiography is a common test, usually performed when patients have unexplained precordial pain, dyspnea, palpitations and other discomforts, and non-invasive tests can not clarify the cause of the disease, highly suspected of coronary artery disease; unexplained arrhythmias, such as recurrent malignant arrhythmias; and unexplained cardiac insufficiency, which can be used to identify dilated cardiomyopathy or ischemic cardiomyopathy. In addition, cardiac angiography can also be performed after intracoronary stent implantation or bypass surgery to clarify the patency of the stent. In conclusion, if you feel unwell, it is recommended to consult a medical professional for standardized diagnosis and treatment.