| Background and-Objective:The incidence rate of right heart failure after a cardiac surgery is about0.1%. It occurs more common to patients with pulmonary hypertension (PH), and is the main cause of death. The irregular shape of right ventricle makes it difficult to assess the right ventricular function. Especially in PH patients, who have right ventricle enlargement, cardiac hypertrophy and interventricular septal abnormal motion. To assess right ventricular function of these patients is quite a challenge.Strain rate imaging(SRI) technology is a new method to evaluate regional myocardial function evolved from Doppler imaging(TDI). It reflects the deformation characteristics of myocardium. Since not affected by the displacement of heart and the traction of adjacent myocardial segments and tissues, global longitudinal strain (GLS) has unique advantages in the evaluation of myocardial function.In this study, tricuspid annular plane systolic excursion(TAPSE), strain(S) are used to analyze ventricular longitudinal myocardium deformability in patients with PH. Aim at:(1)To investigate the features of right ventricular longitudinal myocardium deformability in patients with pulmonary hypertension.(2)To investigate the effect on regional myocardial function caused by right ventricular function or volume overload.(3)To search parameters of strain and strain rate for judging right ventricular load swing.Methods:Philips iE33ultrasound system equipped S5-1probe was used to perform echocardiographic examinations. A total of105patients with PH and25normal subjects were investigated. According to the level of pulmonary artery systolic pressure, the PH subjects were divided into3subgroups:patients with mild PH, moderate PH and severe PH).All patients were examined in the left lateral position by two-dimensional echocardiography. Digital routine grayscale2-D cine loops was obtained from3consecutive beats with end-expiratory apnea from standard apical four-chamber view. Frame rates were>50Hz for grayscale imaging used for speckle-tracking analysis. Sector width was optimized to allow for complete myocardial visualization while maximizing frame rate. Gain settings and the width of the region were adjusted for routine clinical grayscale2-D imaging to optimize endocardial definitionAfter running the program software, GLS and strain of every segment of right ventricular myocardium were obtained.All statistical analyses were performed by PAWS18, and P values<0.05were considered statistically significant. The results were expressed as mean±tandard deviation. Comparisons of values within the same individuals were performed using paired t test, inter-group comparison was tested by t-test. Counting data among groups were compared by chi square test, correlations were determined using linear regression analysis.Results1. There are no differences between two groups in age, sex and heart rate. Compared with controls, TAPSEs were found significantly decreased in PH Groups, while MPI, RVEDS, RVESA, RVEDA were noted significantly increased in PH Groups,, however, there were no significant differences in RVEDD、RVFS、RVFCA.2. The characteristics of the longitudinal strain of right ventricle:MAR is the biggest in PH patients and the controls. In PH patients, BAL, MAL and APR is greater than BIS, MIS and APS, respectively (P<0.05).3. Compared with controls, GLS、BIS、MIS、BAR、MAR in PH patients were found decreased(P<0.05), there were no differences in APS、APR between two groups.4. GLS, BAR were significantly decreased in patients with severe PH, and GLS, BAR in moderate PH group was larger than that of mild PH group (P<0.05). MIS in severe PH group were significant decreased than in mild PH group, and there were no differences between severe PH and moderate PH groups, moderate and mild groups. APS, MAR in severe PH group were significant decreased than moderate PH and mild PH groups, and there was no differences between moderate PH and mild PH groups. APR in mild PH group was increased, and decreased in moderate PH and severe PH groups, but there was no differences were found between moderate PH group and severe PH group. There were no differences in BIS and SR among groups.5. GLS and BAR exhibited the close correlation with TAPSE (r=, P<0.05).Conclusion This study shows that: 1. Distribution of longitudinal strain (S) of normal right ventricular myocardium is characterized as following:right ventricular myocardial longitudinal strain in the middle segment is the largest, and there were no significant difference between each segment in interventricular septum. The middle segment of right ventricular wall has the maxal longitudinal deformation capacity.2. Compared with the controls, GLS and strain of all ventricular segments were lower than that of control group, and most of the segments were found statistically and significantly decreased. TAPSEs were significantly decreased. TAPSEs exhibited closest correlation with GLS and BAR. Therefore, we can speculate that GLS, TAPSE, and BAL have the most reference values in PH patients with right ventricular dysfunction... |
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