Study Of Right Ventricular Myocardial Strain In Patients With Chronic Pulmonary Heart Disease By 3.0T Cardiac Magnetic Resonance And Tissue Tracking Technique

Objective: To evaluate the right ventricular function and strain in patients with chronic pulmonary heart disease(CPHD)by cardiac magnetic resonance tissue tracking(CMR-TT),and to explore a new method for rapid and quantitative assessment of right ventricle longitudinal strain,and to analyze the feasibility,reliability and repeatability of the new method.Methods: From January 2017 to November 2017,45 patients with pulmonary heart disease diagnosed in Affiliated Hospital of North Sichuan Medical College and 33 healthy volunteers were selected.The right ventricular function,global peak strain and global peak displacement(longitudinal,radial and circumferential direction)of two groups(pulmonary heart disease vs healthy volunteers)were measured by 3.0T CMR and heart function software,and the differences between the two groups were compared.The correlation between peak strain,peak displacement and right ventricular ejection fraction(RVEF)were analyzed.In addition,right ventricular long axis strain(RVLAS)including RVLAS-lat,RVLAS-sep,RVLAS-mid were obtained by manual measurement on magnetic resonance images.The differences in RVLAS between the two groups were analyzed,and the correlation between RVLAS,RVEF and Right ventricle global peak strain long(RV-GPSl)were analyzed respectively.For discrimination of controls and patients,right ventricular peak strain,peak displacement,RVLAS,and right ventricular function parameters were analyzed using receiver operating characteristic(ROC)curves.Diagnostic cutoffs,area under the curve(AUC)values,and diagnostic efficacy for pulmonary heart disease were calculated.The reproducibility of RVLAS in assessing right ventricle longitudinal systolic function were analyzed.Results: Finally,there are 33 patients with 69.18±7.99 years,males: 26,females: 7,and 33 healthy volunteers with 65.33±9.35 years,males: 20,females: 13.There are significant differences about RV EDV?RV ESV?RVEF?RV EDV/BSA?RV ESV/BSA?RV Myo Mass(disat)?RV Myo Mass(syst)?RV Myo Mass/BSA(disat)and RV Myo Mass/BSA(syst)between the patients and the control group.In the disease group,except RVEF was significantly reduced,the other parameters of the right ventricular function values were significantly increased.The absolute values of RV-GPS1,RV-PDr and RV-PDl in pulmonary heart disease group were significantly lower than those in control group(P<0.05).Compared with the control group,the absolute values of all RVLAS were significantly decreased in the pulmonary heart disease group(P<0.001).RV-GPSr,RV-GPSc,RV-GPSl and RV-PDr were moderately correlated with RVEF(P<0.01).RVLAS-lat,RVLAS-sep,RVLAS-mid and RVEF / RV-GPSl were moderately correlated(P<0.01)in patients.ROC curve analysis showed that: RV-GPSl,RVLAS-lat,RVLAS-sep and RVLAS-mid have good performance in distinguishing pulmonary heart disease(P<0.05),and RVLAS-lat has the best diagnostic value for pulmonary heart disease,the best cut-off value is-22.548%,AUC = 0.803,sensitivity and specificity are 0.758,0.758,respectively,P<0.001.In RV function parameters,RV Myo Mass/BSA(disat)had the best performance in diagnosing pulmonary heart disease,AUC=0.899,and the sensitivity and specificity were 0.970,0.697,respectively,P<0.001.RVLAS has good repeatability between observers and within observers.Conclusion: CMR-TT could quantitatively analyze right ventricular systolic function.RVLAS is a rapid evaluation parameter to reflect the global longitudinal strain of the right ventricle,without specific software.The measurement method for RVLAS is simple,repeatable,and does not require post-processing software.It is a reliable indicator to evaluate right ventricular systolic function.