1Cardiology Department, St James Hospital, Dublin 8, Ireland
2Cardiovascular Therapeutics Unit, Department of Pharmacology, University of Melbourne, Australia
3University of Tasmania, and Tasmanian Institute of Critical Care, Davenport, Tasmania, Australia
4Dublin Institute of Technology, Kevin Street, Dublin, Ireland
5Medical Physics Department, St James Hospital, Dublin 8, Ireland
6Department of Pharmacology and Therapeutics, St James Hospital, Dublin 8, Ireland