1. Medical School, University of Western Australia , 35 Stirling Highway, Crawley, WA 6009 , Australia
2. Department of Cardiology, Royal Perth Hospital , Victoria Square, Perth WA 6000 , Australia
3. School of Population and Global Health, University of Western Australia , Crawley, WA 6009 , Australia
4. Department of Cardiology, Fiona Stanley Hospital , 11 Robin Warren Drive, Murdoch, Perth, WA 6150 , Australia
5. National Echo Database Australia (NEDA) , 50 Colin Street, West Perth, Perth, WA 6005 , Australia
6. Harry Perkins Institute of Medical Research, Fiona Stanley Hospital , 11 Robin Warren Drive, Murdoch, Perth, WA 6150 , Australia