1 Division of Cardiothoracic Surgery, Mayo Clinic, Phoenix, AZ, USA.
2 Department of Medicine, Kingston Health Sciences Center, Kingston General Hospital, Queen's University, FAPC 3, 76 Stuart Street, K7L 2V7 Kingston, Ontario, Canada.
3 Department of Medicine, Kingston Health Sciences Center, Kingston General Hospital, Queen's University, FAPC 3, 76 Stuart Street, K7L 2V7 Kingston, Ontario, Canada. Electronic address: barancha@kgh.kari.net.