Quantitative Assessment Of Left Ventricular Strain In Patients With Dilated Cardiomyopathy Using Cardiac Magnetic Resonance

Objective: Dilated cardiomyopathy(DCM)can cause structural and functional changes on left ventricle(LV).In this study,we tested if cardiac magnetic resonance tissue-tracking(MR-TT)could be applied to detect LV abnormality in DCM.Methods: 45 subjects with DCM and 25 control subjects were examined using standard cardiac magnetic resonance(CMR).Global and regional strains in LV were analyzed respectively: global peak radial,circumferential,longitudinal strain(GPSR,GPSC,GPSL),and the peak radial,circumferential,longitudinal strains in every segment of LV(PSR,PSC,PSL).LV ejection fraction(LVEF),End-diastolic volume(EDV),End-systolic volume(ESV)and Stroke volume(SV)were measured as well.Results: As compared with controls,we found that the LVEF significantly decreased in the DCM(22.42±11.14% vs.69.25±6.75%,p<0.05).All the global strain indicators of LV significantly decreased(GPSR: 7.99±6.25% vs.37.88±7.50%,p<0.05;GPSC:-3.89±3.1% vs.-14.38±1.86%,p<0.001;GPSL:-3.87±3.6% vs.-11.85±2.2%,p<0.05,respectively).A positive correlation between GPSR and LVEF was informed in this study(r=0.92,p<0.01),while GPSC and GPSL had negative correlations with LVEF(r=-0.94,p<0.01;r=-0.90,p<0.01 respectively).We performed pair-wise comparison among GPSR,GPSC,and GPSL,which showed linear correlations between each other(GPSR vs.GPSC r=-0.973 p<0.01,GPSR vs.GPSL r=-944 p<0.01,GPSC vs.GPSL r=0.967 p<0.01,respectively).The magnitude values of PSR,PSC,and PSL significantly reduced on different levels in most segments(p < 0.05),except the PSC in the apical septal segment and the PSL in the apical anterior and inferior segments respectively(p > 0.05).Conclusions: LV strain in DCM can be quantitatively detected by MR-TT,not only the global LV function changes,but also the segmental strains,which do help to analysis the injured segment.