Institute of Life Sciences, Scuola Superiore Sant’Anna, Pisa, Italy; Division of Cardiology and Cardiovascular Medicine, Fondazione Toscana Gabriele Monasterio, Pisa, Italy; Address for correspondence: Dr. Giuseppe Vergaro, Division of Cardiology and Cardiovascular Medicine, Fondazione Toscana Gabriele Monasterio, Via Moruzzi, 1, 56124 Pisa, Italy.