1 Division of Cardiothoracic Surgery, Oregon Health and Science University, Mail Code L353, 3181 SW Sam Jackson Park Rd, Portland, OR 97239-3098.
2 Division of Cardiothoracic Surgery, Oregon Health and Science University, Mail Code L353, 3181 SW Sam Jackson Park Rd, Portland, OR 97239-3098. Electronic address: songh@ohsu.edu.