The purpose of this study is to evaluate the radiation exposure in patients undergoing coronary angiography, and to identify reference values for the main radiation doses parameters.

Exposure of patients to X-rays during interventional coronary procedures may have deleterious effects, including an increased risk of developing cancer.Individual justification for the procedure and its optimization are the cornerstones of dose-reduction for patients.Radiation exposure is influenced by a variety of technical and clinical factors.Few multicenter data from large populations exist concerning the radiation doses to which patients are exposed during interventional coronary procedures.The aims of this prospective, multicenter survey is to: 1) evaluate the radiation exposure in 4000 patients undergoing coronary angiography by monitoring the parameters of Air kema,fluoroscopy Dose-area product and total Dose-area product; 2) analyze factors associated with variation in radiation dose in everyday clinical practice, such as number of frames, body surface area, sex, age, BMI, arterial approach, fluoroscopy time and so on.

Inclusion Criteria:

• Patients who need to perform coronary angiography

Exclusion Criteria:

• Contrast medium reactions Severe cardiopulmonary insufficiency Uncontrolled severe arrhythmia Uncorrected kaliopenic, digitalism and acid-base imbalance Severe liver and renal dysfunction Hemorrhagic disease Severe infection disease Others who were unwilling to participate the study

residents who need to perform coronary angiography in Hebei province