Clinical Analysis Of Infective Endocarditis Induced Cardiac Conduction Block

Objective: To investigate the clinical characteristics ofpatients with cardiac conduction block caused by infective endocarditis(IE)and the related factors leading to cardiac conduction block,so as to provide evidence for the rational diagnosis and treatment of infective endocarditis.Methods: The clinical data of 233 IE patients hospitalized from June 2007 to June 2017 were retrospectively analyzed.The baseline data,clinical manifestations,susceptibility factors,basic heart disease history,laboratory examination,blood culture(infected microorganisms),12-lead electrocardiogram,cardiac ultrasound(infected sites),types of cardiac conduction block and distribution of infected sites were recorded.233 patients were divided into conduction block group(n=53)and non-conduction block group(n=180)according to whether cardiac conduction block occurred 24 hours after admission.All the data were entered into Excel table.The statistical software SPSS 21.0 was used to measure the data,and the normal distribution was satisfied.The t test was used to compare the two groups,but the normal distribution was not satisfied.The rank sum test was used to compare the two groups,and the constituent ratio or rate was used to count the data.The results showed that chi-square test or Fisher's exact probability method were used to analyze the single factor of cardiac block with multivariate logistic regression.The difference was statistically significant according to the test level P < 0.05,and the risk factors of IE-induced cardiac block were discussed.Result: Single factor analysis showed that male,aortic valve infection,Streptococcus viride infection,rheumatic heart disease,non-O blood group,diabetes mellitus and other factors in conduction block group were significantly higher than those in non-conduction block group(p < 0.05).Logistic multiple regression analysis showed that aortic valve infection and Streptococcus viride infection were the high risk factors for cardiac conduction block(P < 0.001).The most common type of heart block in IE was degree I atrioventricular block,followed by right bundle branch block.No sinoatrial block or intra-atrial block was found.Distribution of infection sites showed that cardiac conduction block could occur in aortic,mitral,tricuspid,pulmonary and prosthetic valves.Aortic valves were most vulnerable to involvement,with bilobar malformation accounting for 53%.Infectious IE of aortic valve can cause various types of conduction block,but no case of bilobar malformation of aortic valve has indoor conduction block.No left bundle branch block occurred in tricuspid,pulmonary and prosthetic valves.Conclusion: Male,rheumatic heart disease,non-O blood group,diabetes mellitus and other factors are associated with conduction block in IE.Aortic valve infection and Streptococcus viride infection are high risk factors for heart block.Aortic valves are most susceptible to involvement.Infectious IE of aortic valve can cause various types of cardiac block.The most common cardiac block in IE is degree I atrioventricular block and right bundle branch block.