扩张型心肌病合并功能性二尖瓣反流患者收缩期左心室流场能量变化特征研究OA

Objective To investigate the characteristics of systolic left ventricular flow field energy changes using vector flow mapping(VFM)in patients with dilated cardiomyopathy(DCM)and different severities of functional mitral regurgitation(FMR).Methods A total of 74 DCM patients who met the inclusion criteria were enrolled,who were treated at the General Hospital of Ningxia Medical University from December 2022 to January 2025.According to the severity of FMR assessed by the flow convergence method,the patients were divided into three groups:no-FMR group,mild-to-moderate FMR group,and severe FMR group.Echocardiography was performed to measure left ventricular end-diastolic volume(LVEDV)and left ventricular end-systolic volume(LVESV),and left ventricular ejection fraction(LVEF)was calculated.Effective regurgitant orifice area(EROA)and mitral regurgitant volume(MRV)were also measured.Pulse-wave Doppler was used to record mitral and aortic valve spectra in the apical left ventricular long-axis view.Based on the spectra,systolic phases were defined as follows:isovolumic contraction period(IVC)was from mitral valve closure(MVC)to aortic valve opening(AVO),and ejection time(ET)was from AVO to aortic valve closure(AVC).Using VFM software,vortex parameters were analyzed at three time points:immediately at MVC,immediately at AVO,and at vortex disappearance(END).The horizontal position(PH),longitudinal position(PL),vortex flow volume(FV),vortex area(VA),decay amplitude of vortex area(ΔVA),and decay amplitude of vortex flow volume(ΔFV)were measured,and their dynamic evolution was observed.Results LVEDV and LVESV were significantly higher,while LVEF was significantly lower in the severe FMR group than in the no-FMR and mild-to-moderate FMR groups(P＜0.01).Compared with the no-FMR group,the severe FMR group showed significantly prolonged IVC(P＜0.05)and shortened ET(P＜0.01).No significant difference was found between the mild-to-moderate FMR group and the severe FMR group.Compared to no-FMR group,PL and PH of the vortex center in FMR group were lower in mid-to-late systole,indicating that the vortex tended to be trapped posteriorly at the left ventricular base.VA gradually decreased during systole in all groups,but Δ VA was significantly greater in the no-FMR group than in FMR groups,especially during the ejection period.There was no significant difference in FV among groups during systole,while ΔFV during ejection was higher in the no-FMR group than in FMR groups(P＜0.05).Conclusion FMR influences the systolic left ventricular flow field in multiple aspects,which makes the flow construction changeful and leads to reduced dynamic efficiency of vortex during systole.