1. Cardiology Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, 634012 Tomsk, Russia
2. Department of Anaesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
3. Department of Anaesthesia, Harvard Medical School, Boston, MA 02115, USA
4. Respiratory Care Service, Patient Care Services, Massachusetts General Hospital, Boston, MA 02114, USA