1. Department of Medicine, Centre for Resuscitation Science, Karolinska Institutet, Södersjukhuset Sjukhusbacken 10, Solna, 118 83 Stockholm, Sweden
2. Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Arwid Wallgrens backe, 413 46 Gothenburg, Sweden
3. Prehospen—Centre for Prehospital Research, University of Borås, 501 90 Borås, Sweden
4. Department of Cardiology, Region Västra Götaland, Sahlgrenska University Hospital, Blå stråket 5, 413 45 Gothenburg, Sweden