1. Division of Cardiology, Department of Medicine, Lutheran Hospital , Fort Wayne, IN , USA
2. Division of Cardiology, Department of Medicine, University of Texas Medical Branch , 301 University Blvd , Galveston, TX 77555, USA
3. Division of Cardiology, Department of Medicine, St Joseph Medical Center , Stockton, CA , USA
4. Division of Cardiothoracic Surgery, Department of Surgery, University of Texas Medical Branch , Galveston, TX , USA