1. Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart Lung and Blood Vessel Disease, Beijing, China;
2. Department of Cardiology, Affiliated Hospital of Hebei University, Baoding, Hebei, China;
3. Department of Cardiology, Qingdao Municipal Hospital, Qingdao, Shandong, China;
4. Department of Cardiology, China National Petroleum Corporation Central Hospital, Langfang, Hebei, China