title: [Laws of syndrome element combination in stable angina pectoris: a study based on cluster analysis and corresponding-correlation analysis].
abstract: OBJECTIVE
  To study the classification of common symptoms and the laws of syndrome element combination in 251 cases of stable angina pectoris (SAP) by using cluster analysis and corresponding-correlation analysis.
  
  
  METHODS
  A total of 251 SAP cases were selected and their information from four diagnosis in traditional Chinese medicine was recorded. The classification of common symptom and the laws of syndrome element combination were investigated by cluster analysis and corresponding-correlation analysis.
  
  
  RESULTS
  Twenty-five symptoms found in 251 SAP cases were divided into four types by cluster analysis: deficiency of heart qi, deficiency of spleen qi, deficiency of qi and yin, and phlegm accumulation and blood stasis. The deficiency of heart qi had the closest relation to phlegm accumulation and blood stasis. By corresponding-correlation analysis, the deficiency of qi had the closest relation to blood stasis, next was turbid phlegm and heat stagnation, and then deficiency of qi and deficiency of yin.
  
  
  CONCLUSIONS
  Blood stasis due to deficient qi is the key factor in pathogenesis of SAP. Deficiency of qi plus blood stasis, deficiency of qi plus deficiency of yin, blood stasis plus turbid phlegm, deficiency of heart qi plus blood stasis plus turbid phlegm are common syndrome element combinations of SAP. It is proved that cluster analysis and corresponding-correlation analysis are the proper methods for studying laws of syndrome element combination.
authors.affiliation: Department of Cardiology, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing 100053, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.forename: Qing-yong
authors.initials: QY
authors.lastname: He
mesh_terms: D000368:Aged; D000787:Angina Pectoris / Q000175:diagnosis / Q000503:physiopathology*; D016000:Cluster Analysis; D017023:Coronary Angiography; D003627:Data Interpretation, Statistical; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008516:Medicine, Chinese Traditional / Q000379:methods*; D008875:Middle Aged