1. Department of Cardiology, Tianjin Nankai Hospital, Tianjin, PR China
2. Department of Medical Ultrasonics, Hainan General Hospital (Hainan Affiliated Hospital of Hainan Medical University), Haikou, PR China
3. Center of Geriatrics, Hainan General Hospital (Hainan Affiliated Hospital of Hainan Medical University), Haikou, PR China