| Rheumatic heart disease , which had a higher morbidity in China, was one of the most common heart diseases. The prognosis was very different due to complicated type, pathological anatomy, hemodynamics, and clinical manifestation, which had been already improving after the heart surgery. The valves damage was the most significant among involved myocardium,pericardium, endocardium and valves, one or more were involved possibly,the most was mitral valve, then was aortic valve, and tricuspid valve and valve of pulmonary trunk were the least. Involved valves might have stenosis or insufficiency in different degree, of which prosthetic valve replacement was the most effective therapy method.Objective: to study the strain value of local and global left ventricular myocardium pre-operation, one month and six months after the prosthetic mitral and aortic valves replacement of the rheumatic heart disease patients by two-dimensional strain echocardiography(2D-SE), to provide a new diagnosis method for observing myocardial motion and quantitative evaluation of myocardial function after prosthetic valve replacement.Methods: The case group was 30 rheumatic heart disease patients undergone prosthetic mitral and aortic valves replacement in China-Japan Union hospital from October, 2007 to February, 2009, pre-operative, one month and six months after the operation were observed, 13 were male, 17 were female, the age was from 33 to 69 years old, and the average was 49.03±1.78 years old. The control group was 30 healthy volunteers without heart and pulmonary disease, examined by chest film, ultrasonography and electrocardiogram,12 were male, 18 were female, the age was from 20 to 68 years old, and the average was 43.33±2.53 years old. The patients were placed in lateral recumbent position and connected with ECG, the measurement indexes of two-dimensional echocardiography were routine observed during quiet respiration. Dynamic image of three cardiac cycles from apical long axis view(APLAX), four-chamber view(A4C) and two-chamber view(A2C) were detected with AFI analysis software of 2D-SE,the left ventricular endocardium of each dynamic image of each systole among the valve ring and apex was analyzed automatically after tracings under strain imaging mode, the deformation of each myocardial segment in region of interesting was calculated according to the tissue gray scale auto-tracing of different pixel myocardium frame position. The six left ventricular walls of the three views were equally divided into basal segment, intermediate segment and apical segment(18 segments) automatically by the system, and the peak systolic strain (ε) , strain curve, the whole cardiac strain and bovine trabecular image were obtained. Meanwhile the left ventricular ejection fraction (LVEF) was measured by three-dimension tri-plane method. All the data collected expressed by mean±standard deviation were analyzed by SPSS 11.0, mean t-test was done between groups, and paired t-test was done between pre- and post-operation of the patients. The correlation between LVEF measured by 3D-3 plane method and the mean of global left ventricular strain was analyzed by linear regression, P values that were less than 0.05 were considered statistical significance.Results: (1) Comparison of strain value of left ventricular segments: the strain of most segments of one month after the operation was lower than that of pre-operation, and there were significant differences in intermediate segment of posterior wall, posterior septal, lateral wall and apical segment of inferior wall between two groups. The strain of six months after the operation was obviously higher than that of one month after the operation, there were significant differences except posterior wall and posterior septal. The strain of six months after the operation was obviously higher than that of pre-operation except posterior wall and anterior septal apical segment, there were significant differences, but still lower than that of the control group. (2) Comparison of strain of left ventricular views and average of global left ventricle of four groups: the strain of APLAX, A4C and A2C of the case group were all lower than that of the control group. The strain of one month after the operation was obviously lower, and the strain of six months after the operation was higher than pre-operation and one month after the operation, and the differences were significant. The average of global left ventricular strain (GLS-AVG) of the case group was lower than that of the control group, the measured value of one month after the operation was the lowest, and that of six months after the operation was advancing higher than pre-operation, the differences were significant. (3) The correlation between GLS-AVG and LVEF measured by three-dimensional tri-plane method: The LVEF trend measured by 3D-3 plane method accorded with the GLS-AVG trend measured by 2D-SE, the results analyzed by linear regression showed that the two ways had a relation. The correlation coefficient was 0.48, 0.46,0.43,0.47 respectively.Conclusions: The strain values of local and global left ventricular myocardium of the control group and pre-operation, one month and six months after the prosthetic mitral and aortic valves replacement of the case group were studied by two-dimensional strain echocardiography, the LVEF etc. was measured by three-dimensional tri-plane method, the results showed that the indexes of the case group were all lower than those of the control group, and the indexes of one month after the operation were the lowest, which related directly to the operative myocardium reperfusion injury and the myocardial systolic and diastolic function influenced by resection of valves, and it needed a period to recover. The indexes of 6 months after the operation were higher than those of 1 month after the operation, even higher than pre-operation, which showed that the compensation ability of the myocardial systolic function was very powerful, with the improvement of hemodynamics, the state of whole body gets recovered, and the conversion, the storage and the use of the energy had been improved, the ability of the myocardial systolic function had recovered gradually. The LVEF value measured by three-dimensional tri-plane method accorded with the GLS-AVG trend measured by two-dimension strain ultrasonic imaging technology , the results analyzed by linear regression showed that the two ways had a relation. The local and whole myocardial systolic function can be quantitative evaluated by2D-SE, and the strain of whole left ventricle taken as a parameter of myocardial function will make it convenient in clinical application.To sum up, two-dimension strain ultrasonic imaging technology, taken as a new way of evaluation of the whole left ventricular function and local myocardial strain, not only has the advantages of noninvasive, cheap, simple operation, and repeated followed up as the traditional ultrasonography, but also has the new advantages of non-angle dependence, strong practicality and good reproducibility, which can quantitatively evaluate the local and whole left ventricular myocardial motions of the rheumatic heart disease patients pre-and post prosthetic mitral and aortic valves replacement, also provide the objective basis for the evaluation of operative therapeutic effect.
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