Changes Of Heart Rate Variability In Children With Endocardial Fibroelastosis And Its Correlation With Cardiac Structure And Function And NT-proBNP

BackgroudEndocardial fibroelastosis(EFE)is a kind of endocardial cardiomyopathy,which is more common in infants,the typical pathological changes are elastic fibers and collagen fiber hyperplasia under encardium,leading to ventricular wall and intimal thickening,attributing to cardiac dilatation,ventricular compliance reduction,cardiac systolic and/or diastolic dysfunction,eventually cause congestive heart failure.Endocard biopsy is the gold diagnosis standard of EFE,but it's difficult to implement,Clinical diagnosis is mostly according to the onset ages,clinical manifestations and auxiliary examination,and color doppler echocardiography is the most important auxiliary diagnosis method so far,but a large number of clinical practice showed that the LVEF(left ventricular ejection fraction),LVFS(left ventricular fraction shortening)are influenced by many factors.and strong subjective.As a result,they are not very consistent with the clinical manifestations.HRV(heart rate variability)is a research hotspot in recent years,it represents the sinus heart beat of the tiny differences between successive cardiac cycle,which is a quantitative,non-invasive assessment of autonomic nervous system activity.A large number of studies have shown that the reduction of HRV parameters is an adverse prognostic factor for cardiovascular diseases such as chronic heart failure,acute myocardial infarction,and sudden cardiac death.ObjectiveTo analyze the changes of heart rate variability(HRV)in children with endocardial fibroelastosis(EFE),to explore the correlation between HRV and cardiac structure and function and amino terminal brain natriuretic peptide(NT-proBNP),and evaluate the diagnosis value of HRV and its influence on diagnosis and prognosis in EFE.Methods48 children with EFE admitted in the the First Affiliated Hospital of Zhengzhou from June 2011 to Agust 2018 were enrolled in the study,and all of them underwent HRV test within one week after admission.30 children were selected as control group for the same time in our outpatient,who complet echocardiogram and 24-hour ambulatory electrocardiogram which showed that they were without organic heart disease and obvious arrhythmia.The gender,age,body weight,modified ROSS score,and serum amino-terminal brain natriuretic peptide precursor(NT-proBNP)values were recorded in two groups,and the HRV indicators in ambulatory electrocardiogram included Domain indicator [normal sinus NN interval standard deviation(SDNN),standard deviation of the mean value of N-N interval every 5 min in all records(SDANN),root mean square value(rMSSD)of adjacent NN interval difference,phase The difference between adjacent NN intervals >50ms of heart rate as a percentage of total heart rate(PNN50)] and frequency domain indicators [high frequency power(HF),low frequency power(LF)and low frequency / high frequency(LF/HF),finally the indicators in echocardiogram were recorded:Left atrium end-diastolic diameter(LAEDd),left ventricular end-diastolic diameter(LVEDd)and intel-ventricular scptum end-diastolic thicknessv(IVSTd),Left Ventricular Posterior Wall Depth(LVPWd),left ventricular ejection fraction(LVEF),left ventricular fraction shortening(LVFS),and calculate the ventricular remodeling index LVMI(Left ventricular mass index).The changes of HRV in children with EFE were studied.The differences of HRV indexs between different cardiac function grades,different ejection fractions and different NT-proBNP levels were analyzed.The interventricular ventricular remodeling index,LVEF,LVFS and NT-proBNP level are different in different SDNN level groups.The correlation between HRV and cardiac structure and function indexes and NT-proBNP levels was analyzed by Spearman correlation.Results1.Compared with the control group,PNN50,SDNN,rMSSD,SDANN,HF and LF in EFE group were lower(P<0.01 or P<0.05),while LF/HF was higher(P<0.05);2.Compared with control group,PNN50,SDNN,rMSSD,SDANN,HF,LF were significantly lower in the cardiac function grade ? group(P < 0.05),LF/HF had no difference(P > 0.05),compare with cardiac function grade ? group,SDNN,SDANN,LF were lower statistically significant in cardiac function grade ? group(P < 0.05).Compared with control group,the reducing indexes had no differences in cardiac function grade ? group and the cardiac function grade ?(P > 0.05);3.In the control group,the left ventricular ejection fraction mildly reducing group,moderately reducing group and severly reducing group,SDNN,SDANN,PNN50,rMMSD,HF,LF indexes decrease were statistically significant(P < 0.05),LF/HF had no difference(P > 0.05)SDNN,SDANN,PNN50,rMMSD,HF,LF.in ejection fraction severely reducing group were significantly lower than that in the control group(P < 0.05).Compared with mildly reducing group,SDNN,SDANN,LF index decreased significantly in ejection fraction severely reducing group(P < 0.05),However,there was no difference between the other groups(P > 0.05);4.Compared with control group,SDNN,SDANN,PNN50,rMMSD,HF,LF decreased in high level NT-proBNP group(P < 0.05)Contorl with low level group,SDNN,SDANN,rMMSD,HF,LF decreased in high level group(P < 0.05),mediate level group VS control group,HF decreased(P < 0.05);5.The more severely the autonomic nerve damage,the higher the LVEDD,LVMI,NT-proBNP level,the lower the LVEF,LVFS,the differences between the groups were statistically significant(P < 0.05);6.Spearman correlation analysis showed that SDNN and SDANN were positively correlated with LVEF and LVFS,and were negatively correlated with LVEDD,LVMI;NT-proBNP level has negative correlation with SDNN,SDANN,rMMSD,PNN50,LF,HF,and no significant correlation with LF/HF;While NTproBNP level was negatively correlated with LVEF and LVFS,but was positively correlated with LVEDd and LVMI.There is no correlation with IVSTd,LVPWd,LAEDd.7.According to the SDNN value,the SDNN>70ms,SDNN?70ms two groups,12 months as the follow-up end point,the cardiac structure and function of the two groups returned to the normal ratio: 81.8%,39%,the difference was statistically significant(P<0.05).Conclusion1.Children with EFE has wide autonomic nerve dysfunction;2.The reduction of HRV indexs is associated with the degree of heart failure in children with EFE,which is more obvious in severe heart failure;HRV can be used to assess the severity of disease in children with EFE,and may be an important reference index for predicting disease;3.The size of SDNN may be used as an indicator of prognosis for EFE.