1 (a)Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany; (b)1(st) Department of Cardiology, Medical University of Warsaw, Warsaw, Poland.
2 (a)Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany; (c)Montréal Heart Institute, University de Montréal, Montréal, Quebec, Canada; (d)Department of Molecular Physiology & Biophysics, Baylor College of Medicine, Houston, USA. Electronic address: dobromir.dobrev@uk-essen.de.