Influential Factors Of Heart Rate Deceleration In Patients With Dilated Cardiomyopathy And Its Early Warning Effect On Prognosis

Objective: To investigate the factors influencing the change of heart rate deceleration capacity(DC)in patients with dilated cardiomyopathy(DCM)and to evaluate its early warning effect on prognosis.Method: DC and heart rate acceleration capacity(AC)value were detected in100 cases of DCM patients(DCM group)and 202 normal physical examines cases(control group)by using 24 h dynamic electrocardiogram.The cardiac structure and function were detected by using echocardiography.Compared the difference between DC and AC values of the two groups,and analyzed the correlations of DC value with age,sex,echocardiographic parameters including the left atrial diameter(LAD)and left ventricular end-systolic dimension(LVESD).Followed up with DCM patients,and cardiac death was the endpoint event(mean follow-up time:40.1±2.44).Analyzed the ROC curve of DC value predicting CD in DCM patients.The association pattern between DC value and survival rate in DCM patients were studied by Kaplan-Meier and Cox regression analysis.Results: Compared with control group,the DC values in DCM group were obviously lower(7.3±1.81 vs 4.4±2.03,P < 0.01),the proportion of DC value <4.5ms increased significantly(6% vs 62%,P < 0.01);In DCM group DC values were negatively correlated to the LAD(r= 0.366,P < 0.01),positively correlated to the LVEF(r=0.241,P<0.01),and LAD is an independent influence factor of DC value decrease;In LAD≤40mm,40 mm < LAD≤5mm and the LAD>50mm groups,patients with DCM have a gradual decline in the DC value(5.6±2.04 vs 4.5±2.07 vs 3.6±1.62,P<005);Compared to low risk patients in DCM group,AC values were increased(-5.0±2.31 vs-3.9±1.43,P<0.05),DC values were decreased(4.7±2.18 vs 3.6±1.36,P<0.05),LAD values were increased(45.7±7.29 vs 53.3±7.57)and LVESD values were increased(58.7±9.02 vs 62.7±6.45);The predicted value of LAD of DCM patients with CD happen is height,and the predicted value of AC,DC,LVESD are moderate.DC<4.75 ms and LAD≥46.5mm are the independent risk factors affecting the prognosis of patients with DCM,and the survival rate were significantly decreased.Conclusion: DC values in DCM group were reduced,and the DC value negatively correlated with the LAD,and LAD is an independent influence factor of DC value decrease,DC<4.75 ms is independent risk factor affect the prognosis of DCM patients,and DCM patients of DC<4.75 ms survival rate were significantly lower.