Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec Heart & Lung Institute, Laval University, Québec City, Québec, Canada. University of Ottawa Heart Institute, Ottawa, Ontario, Canada. St. Boniface General Hospital, Winnipeg, Manitoba, Canada. McMaster University, Hamilton, Ontario, Canada. University of California San Diego, La Jolla, CA, USA. Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec Heart & Lung Institute, Laval University, Québec City, Québec, Canada. Electronic address: philippe.pibarot@med.ulaval.ca. University of California San Diego, La Jolla, CA, USA. Electronic address: stsimikas@ucsd.edu.