Vincent F M Segers1, Hein Heidbuchel2. 1. Department of Cardiology, University Hospital Antwerp, Edegem, Belgium; Laboratory of Physiopharmacology, University of Antwerp, Antwerp, Belgium. 2. Department of Cardiology, University Hospital Antwerp, Edegem, Belgium; Cardiovascular Research Group, University of Antwerp, Antwerp, Belgium. Electronic address: hein.heidbuchel@uza.be.