Characteristics And Significance Of Deceleration Capacity Of Rate In Patients With Sinus Bradycardia

Objective To analyse the characteristics of DC in patients with sinus bradycardia younger than sixty years,and provide certain reference value for clinical treatment of sinus bradycardia.Methods We selected 204 outpatient patients diagnosed with sinus bradycardia(SB group,n=204)and 104 health subjects(control group,n=104)from January 2015 to March 2017 in the the Department of Cardiology of the first affiliated hospital of Soochow university.We collected the results of 24 Holter monitoring of them,and we analyzed the changes of deceleration capacity of rate(DC),accelaration capacity of heart rate(AC),heart rate variability(HRV).The HRV indicators include standard deviation of all NN intervals(SDNN),the root mean square successive differences between successive R-Rintervals(rMSSD),PNN50,low-frequency and high-frequency.RESULTS(1)Compared with the control group,the DC value,absolute value of AC,and the correlation index of HRV increased in sinus bradycardia group(P <0.05);(2)In the two groups,the indictors of age above 40 were lower than those of younger than 40 years.(3)The DC value had no significant difference between the male and female both in the control group and the sinus bradycardia group.Compared with the control group,the DC value of male and female in the the sinus bradycardia group were both increased markedly.(4)In the control group,the Dc value and absolute value of AC was positively correlated with HRV,But the correlation between DC value and HRV in sinus bradycardia group was significantly less than in control group.Conclusion :1、The DC value increased in patients with sinus bradycardia,suggesting that the vagus nerve function increased;2、The correlation between DC value and HRV index is little in patients with sinus bradycardia,The results suggest that the autonomic nervous function of the sinus bradycardia group is imbalance.