Distribution of traditional Chinese medicine syndromes and syndrome elements of chronic heart failure based on network analysis and hierarchical cluster analysis

Objective: To explore the distributions of syndromes and syndrome elements of chronic heart failure (CHF), so as to provide a point of reference to the research on diagnosis and treatment of CHF, the study on syndrome standardization, and objective research of TCM diagnosis. Methods: The clinical research articles on CHF syndromes in recent 40 years were retrieved from Wanfang Data, CNKI, CqVIP, SinoMed, PubMed, Scopus, Web of Science, and Embase. The cumulative frequencies of CHF syndromes, syndrome elements, and their corresponding cases were counted and compared. The syndrome elements were analyzed by network analysis, and the symptoms were analyzed by hierarchical cluster analysis. Results: A total of 278 Chinese articles with 71 syndromes and 31 syndrome elements were included after two rounds of screening. The research on CHF syndrome has kept a regular activeness till now, but its development was geographically uneven. The distribution of CHF syndromes gained from the cumulative frequencies of syndromes appeared in the articles were in line with that gained from the cumulative frequencies of the cases corresponding to syndromes. The network analysis found four communities of syndrome elements, indicating the deficiency-excess in complexity of CHF pathology, which can be inferred as some common CHF syndromes. The hierarchical cluster analysis on CHF symptoms showed that the distribution of CHF syndromes included five types. Conclusion: The distribution of CHF syndromes includes syndrome of qi deficiency with blood stasis, syndrome of qi and yin deficiency, syndrome of yang deficiency with water retention, syndrome of heart blood stasis obstruction, syndrome of turbid phlegm, and syndrome of collapse due to primordial yang deficiency. The syndrome elements on location of illness are heart, kidney, lung, and spleen, and the syndrome elements on nature of illness are qi deficiency, blood stasis, yang deficiency, yin deficiency, water retention, and turbid phlegm.