1. Department of Cardiology, General Hospital of Thessaloniki G. Papanikolaou, Thessaloniki, Greece
2. Department of Cardiology, General Hospital of Serres, Serres, Greece
3. Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, People's Republic of China