The aim of this study is to perform a whole-genome linkage analysis for identification of the susceptibility loci for POCD

BACKGROUND: Postoperative cognitive dysfunction is probably the most frequent type of postoperative cognitive impairment. As it mainly affect the elderly population, POCD is receiving increasing attention. However, the pathophysiology of POCD remains incompletely understood. No study had elucidate why somebody are apt to suffer from POCD, but others not. In current study, we try to use GWAS technology to find out whether there is a correlation between POCD and gene specificity.

DESIGNING: 120 patients will be screened who are schedule to receive selective on-pump cardiac surgery， 5 ml blood of the patient will be collected before anesthesia induction. Investigetors will measure the cognitive function of the patients one day before surgery and 7 d after surgery and identify whether the patient suffer from POCD used in MMSE test. Randomly select 36 patients who suffer from POCD and 36 patients without POCD(control), GWAS technology will be used to screen the susceptibility gene between these two groups.

EXPECTED RESULTS ：Find out some susceptibility genes correlate to POCD.

CONCLUSIONS: The patients who are apt to suffer from POCD have some special susceptibility genes differ from normal people.

Inclusion Criteria:

1. Age from 60 to 75 years old;
2. Schedule for on-pump cardiac surgery;
3. undergoing full intravenous anesthesia;
4. without hepatic, renal, pulmonary disease or full intravenous anesthesia surgery history;
5. Gave the informed consent.

Exclusion Criteria:

1. Emergency surgery;
2. A history of cerebrovascular disease;
3. The history of mental disease;
4. Long term use of sedative and antidepressant drugs;
5. Alcoholism;
6. serious vision, hearing impairment and inapprehensive language;
7. chromosomal abnormalities;
8. blood disease;
9. refused to sign the informed consent.

Old patient(>60 y) who are schedule to receive of-pump cardiac surgery.