Assessment Of Right Ventricular Systolic Function In Patients With Silicosis By Speckle Tracking Imaging

Objectives The aim of this study is to assess right ventricular systolic function in patients with systolic by 2-dimensional speckle tracking imaging(2D-STI), and to study the effect of the systolic on the right ventricular systolic function.Methods2D-STI was performed in 79 patients with silicosis in our hospital during March 2013 to August 2015, patients were divided into 3 groups according to the stage(stage I, n=43;stage II, n=21;stage III,n=15), and 33 health subjects were chosen as control, the age, sexy,height, weight of whom were comparative.1、Lung function measuring equipment from JAEGER company was used for lung function testing of VC, FVC, FEV1 percentage of expected value and FEV1 % in patients with silicosis and the control group volunteers. We compare the difference between the case group and control group, and among the lung function in I period, II period and III period in patients with silicosis.2、Using GE VIVID E9 color doppler ultrasonic diagnostic apparatus and S5-1 probe to collect the data of right ventricular image, and to detect the end-diastolic right ventricular anterior wall thickness(RVAW), right ventricular end-diastolic basal diameter(RVEDl), right ventricular end-diastolic middle diameter(RVED2), right ventricular end-diastolic long axis diameter(RVED3), end systolic right atrium long axis diameter(RADl), end systolic right atrium diameter(RAD2), end systolic main pulmonary artery diameter(MPA), tricuspid ring displacement(TAPSE), pulmonary artery pressure(PASP)and right ventricular area change rate(RVPCA). In addition, using the workstation of EchoPAC, to detect two-dimensional speckle tracking technology related indicators, such as the systolic peak velocity of basal and middle segment of right ventricular free wall(Vs),the peak systolic strain(S) and the peak systolic strain rate(SRs). These indicators were compared in the control group and the case group and among different stages of patients.At the same time, we make the correlation analysis with the two-dimensional speckle tracking technology parameters and silicosis stage.Results Pulmonary function test showed that VC, FVC, FEV1 percentage of expected value in patients with silicosis group was decreased, comparing with control group, meanwhile,these indicators gradually reduced with increasing silicosis stage. The indicators of RVAW and RVED2 in the patients with silicosis group II, III period were significantly increased comparing with I period patients and the control group(P<0.05). However, there was no significance in the control group and the patients with silicosis group I(p>0.05);and the other indicators were comparative in all the groups. The indicators of PASP was increased and RVPCA was decreased in the patients with silicosis group II, III(P < 0.05),comparing to the control group and the patients with silicosis group I.The indicator of TAPSE in III period patients was significantly lower than the I, II period patients and the control group(p < 0.05), which suggest the right ventricular systolic dysfunction in the III phase silicosis patients. The results of with Two-dimensional speckle tracking technology showed that Vs, S, SRs of basal segment right ventricular free wall and middle period were significantly decreased(P<0.05), and the indicators of S, Vs of basal and middle segment of right ventricular free wall in the patients of II, III silicosis were lower than the control group and the group of patients in I period of silicosis( P<0.05), and there was no significant difference in SRs(P>0.05). In patients with silicosis group, there were obvious correlations between the stages of silicosis and Vs, S and SRs(r = 0.654, P < 0.05, r =0745, P < 0.05 and r = 0.561, P < 0.05, respectively).Conclusion The right ventricular systolic function was damaged, the pulmonary artery systolic pressure was increased, and the respiratory function was decreased in patients with silicosis damage, meanwhile,the severity gradually increased with the progress of silicosis.In addition, the two-dimensional speckle tracking technology was more sensitive and accurate to evaluate the right heart function, and detect the early change of right ventricular function in patients with silicosis.