Vincenzo Marafioti1, Giovanni Benfari2. 1. Cardiovascular and Thoracic Department, University Hospital of Verona, P. Stefani 1, 37126, Verona, Italy. vincenzo.marafioti@fastwebnet.it. 2. Cardiovascular and Thoracic Department, University Hospital of Verona, P. Stefani 1, 37126, Verona, Italy.