1. Department of Cardiovascular Surgery, Affiliated Hospital of Southwest Jiaotong University, The General Hospital of Western Theater Command, Chengdu, China.
2. Department of Health Service, Tibetan Military General Hospital, Lhasa, China.
3. Department of Neurology, Tibetan Military General Hospital, Lhasa, China.
4. Department of Cardiology, Tibetan Military General Hospital, Lhasa, China.