1 Department of Physiology, McGill University, Canada.
2 Department of Cardiac, Thoracic, Vascular Sciences and Public Health, and Department of Biomedical Sciences, University of Padova, Italy.
3 Institute of Cardiovascular and Medical Sciences, University of Glasgow, UK.
4 National Institute of Optics and European Laboratory for Non Linear Spectroscopy, Italy; Institute for Experimental Cardiovascular Medicine, University Freiburg, Germany. Electronic address: sacconi@lens.unifi.it.