1 Department of Cardiology and Cardiovascular Research Institute Basel (CRIB), University Hospital Basel, University of Basel, Petersgraben 4, CH-4031 Basel, Switzerland.
2 Department of Cardiology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN 55902, USA.
3 Department of Radiology, Mayo Clinic, 200 1st Street Southwest, Rochester, MN 55902, USA.