1. Department of Cardiology; Patras University Hospital; Patras Greece
2. Department of Cardiology; Athens General Hospital “G. Gennimatas”; Athens Greece
3. Department of Cardiology; Larissa University Hospital; Larissa Greece
4. Department of Cardiology; Alexandra General Hospital; Athens Greece
5. Department of Cardiology; Iraklion University Hospital; Iraklion Greece
6. 1 Department of Cardiology; Ippokration General Hospital; Athens Greece
7. Department of Cardiology; Ioannina University Hospital; Ioannina Greece