The Change And It’s Significance Of Electromechanical Coupling Time In Patients With Hypertrophic Cardiomyopathy

ObjectiveHypertrophic cardiomyopathy(HCM)is the most common hereditary cardiomyopathy in clinical.Patients diagnosed with HCM often face the risk of sudden cardiac death,heart failure,atrial fibrillation and atrial fibrillation-related stroke.Cardiac activity includes electrical and mechanical activities,combined with previous studies,it is suggested that patients with stage B clinical heart failure have significantly prolonged cardiac electrical-mechanical coupling time parameters.This study mainly to research the change and clinical significance of cardiac electromechanical coupling time in patients with HCM,and to provide help for the diagnosis and disease evaluation of HCM patients.Method1.Select patients diagnosed or excluded of HCM in Shaanxi Provincial People’s Hospital from May 2018 to February 2020,and divide them into HCM group(82 cases)and Control group(86 cases)according to the enrollment criteria.Collected the general condition,medical history,blood biochemical indexes,cardiac ultrasound indexes,and sampling volume measured by tissue Doppler and electrocardiogram are placed in the interventricular septum(IVS)and the Lateral wall of left ventricle(Lat)the cardiac electromechanical coupling time parameter index IVS-QSb,IVS-QSt,Lat-QSb,Lat-QSt.2,Follow-up and regrouping:Heart failure(HF)events or new Atrial fibrillation(AF)were used as the follow-up endpoints for patients in the HCM group;the rest of the patients were followed up until February 2021.Patients in the HCM group were divided into HF group and NHF group based on whether a heart failure event occurred;patients in the HCM group were divided into AF group and NAF group based on whether atrial fibrillation occurred in the HCM group.3.Using R language,compare the differences in cardiac electromechanical coupling time and other indicators between HCM group and Control group,HF group and NHF group,AF group and NAF group,and further explore whether the cardiac electromechanical coupling time can be used as a clinical practice for HCM patients predictors of event occurrence.Result1.Comparison between HCM group and Control group:IVS-QSb:68.83±7.39ms VS.20.45±4.72ms,P<0.001;IVS-QSt:92.51±12.17ms VS.46.63±6.15ms,P<0.001;Lat-QSb:85.44 ±7.58ms VS.27.42±6.28ms,P<0.001;Lat-QSt:107.74±11.18ms VS.58.86±5.62ms,P<0.001;HCM group IVS-QSb,IVS-QSt,Lat-QSb,Lat-QSt Higher than the Control group are statistically significant.2.Comparison between HF group and NHF group:IVS-QSb:75.21±4.98 ms VS.66.90±6.92 ms,P<0.001;IVS-QSt:103.68±10.66 ms VS.89.14±10.52ms,P<0.001;Lat-QSb:90.89±6.47 ms VS.83.79±7.14ms,P<0.001;Lat-QSt:124.53±3.88ms VS.102.68±6.82ms,P<0.001;HF group IVS-QSb,IVS-QSt,Lat-QSb,Lat-QSt Higher than NHF group with statistically significant.3.Comparison between AF group and NAF group:IVS-QSb:71.70±6.79 ms VS.67.90±7.39 ms,P<0.05;IVS-QSt:94.40±12.63 ms VS.91.90±12.05 ms;Lat-QSb:88.05±6.61 ms VS 84.60±7.72ms;Lat-QSt:108.30±5.92 ms VS.107.56±12.45 ms;IVS-QSb in AF group is higher than NAF group with statistical significance.IVS-QSt,Lat-QSb,Lat-QSt in AF group are higher thanNAF group,there was no statistical significance.4.Cox regression analysis of the time of heart failure event and electromechanical coupling and other indicators in HCM group:Lat-QSb:HR=1.400,95%CI=(1.100-1.700),P<0.05;Lat-QSt:HR=1.200,95%CI=(1.000-1.500),P<0.05;MB:HR=1.002,95%CI=(1.000-1.004),P<0.05;LAVI:HR=1.200,95%CI=(1.000-1.500),P<0.05:PR:HR=0.920,95%CI=(0.860-0.990),P<0.05;Lat-QSb,Lat-QSt,MB,LAVI and PR are independent predictors of heart failure events in HCM patients Factors and a fitable model can predict the occurrence of heart failure events in HCM patients.The COX regression model is tested by C-index=0.91877058 and the nomogram is drawn.5.The COX regression model was used to predict the heart failure events of HCM patients,grouped according to the cutoff score of 230.65,and the KM curve was drawn.There was a significant difference in the probability of heart failure events between the two groups(P<0.001).6.COX regression model is used for ROC curve analysis,and the prediction sensitivity and specificity of the fitted model based on the cardiac electromechanical coupling time parameter is relatively high(AUC=0.948,P<0.001).Conclusion1.Cardiac electromechanical coupling time IVS-QSb,IVS-QSt,Lat-QSb,Lat-QSt showed a prolonged trend in HCM patients.2.Lat-QSb,Lat-QSt,MB,LAVI and PR are independent predictors of heart failure events in HCM subjects in the study.3.Based on the prediction model fitted by Lat-QSb and Lat-QSt,it can predict whether heart failure events will occur in HCM patients in this study.