1. The Keenan Research Centre at the Li Ka Shing Knowledge Institute of St. Michael's, University of Toronto, Toronto, Ontario, Canada;
2. Department of Anesthesia, University of Toronto, Toronto, Ontario, Canada;
3. Department of Surgery, University of Toronto, Toronto, Ontario, Canada;
4. Department of Physiology, University of Toronto, Toronto, Ontario, Canada;
5. Institute of Physiology, Charité-Universitätsmedizin Berlin, Berlin, Germany; and
6. German Heart Institute, Berlin, Germany