Correlation between left ventricular remodeling and heart rate variability,ventricular arrhythmia in dilated cardiomyopathy:based on cardiac magnetic resonance

HU Siyin; HE Zhenduo; DU Yongxing; LIN Xiaoxin; OUYANG Yufeng; HUANG Yuli; CHEN Haixiong

doi:10.12122/j.issn.1674-4500.2025.02.07

Abstract：Objective To investigate the correlation between left ventricular remodeling parameters and heart rate variability(HRV),as well as the correlation between left ventricular remodeling parameters and ventricular arrhythmia(VA)in patients with dilated cardiomyopathy(DCM).Methods Clinical data,cardiac magnetic resonance(CMR)data and 24 h dynamic electrocardiogram data were collected from 44 patients diagnosed with dilated cardiomyopathy at Shunde Hospital of Southern Medical University from July 2019 to March 2024 as well as 23 healthy controls.Left ventricular remodeling parameters,degree of myocardial fibrosis,and HRV indicators of two groups were obtained and the differences of those parameters between two groups were analyzed.Left ventricular remodeling parameters included left ventricular ejection fraction(LVEF),left ventricular end-diastolic volume index(LVEDVI),left ventricular end-systolic volume index(LVESVI),left ventricular stroke volume index(LVSVI),cardiac index(CI),and left ventricular myocardial mass index(LVMMI).HRV indicat ors included standard deviation of all NN intervals(SDNN),standard deviation of the averages of NN intervals in all 5 min se gments(SDANN),the square root of the mean of the sum of the squares of differences between adjacent NN intervals(rMSSD),the proportion of interval differences with successive NN intervals greater than 50 ms to all NN interval differences(pNN50),low frequency power(LF),high frequency power(HF),and low frequency power to high frequency power ratio(LF/HF).DCM patients were classified into normal HRV(SDNN≥100)and reduced HRV(SDNN<100)subgroups to compare the differences of left ventricular remodeling indicators.Additionally,based on the Lown classification of premature ventricular contractions,DCM patients were divided into low-risk VA and high-risk VA subgroups to explore related risk factors for the occurrence of high-risk VA.Results The DCM group had significantly lower LVEF,LVSVI and CI compared to controls,while LVEDVI,LVESVI and LVMMI were higher,with 91%of patients in the DCM group exhibiting myocardial fibrosis(P<0.05).HRV indicators,including SDNN,SDANN,LF,HF and LF/HF,were significantly lower in the DCM group.In the reduced HRV subgroup,LVEF was lower,and LVESVI and LVMMI were higher compared to the normal HRV subgroup(P<0.05).Besides,the high-risk VA subgroup displayed more severe myocardial fibrosis than the low-risk group(P<0.05).Logistic regression analysis showed that the degree of myocardial fibrosis is an independent risk factor for the occurrence of high-risk VA.Conclusion Patients with DCM exhibit left ventricular remodeling and varying degrees of HRV reduction,of which left ventricular remodeling and impaired autonomic nerve function are correlated,with myocardial fibrosis serving as an independent risk factor for high-risk VA.CMR examination is crucial for risk stratification,aiding in early intervention and treatment.