1. Department of Geriatric Cardiology, General Hospital of the Southern Theatre Command, PLA, Guangzhou 510016, China
2. The First School of Clinical Medicine, Southern Medical University, Guangzhou 510515, China
3. Department of Cardiology, Zhujiang Hospital, Southern Medical University, Guangzhou, China
4. The Second School of Clinical Medicine, Southern Medical University, Guangzhou 510280, China