1 Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, MA; Harvard Medical School, Boston, MA.
2 Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL.
3 School of Nursing, University of Alabama at Birmingham, Birmingham, AL.
4 Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, AL; Section of Cardiology, Birmingham Veterans Affairs Medical Center, Birmingham, AL. Electronic address: [email protected].