Evaluation Of Right Ventricular Function In Patients With Different Degrees Of Stenosis Of Right Coronary Artery By Two-dimensional Speckle Tracking

Objective: Two-dimensional speckle tracking imaging(2D-STI)technique was used to observe the regional right ventricular longitudinal strain(S)and global right ventricular longitudinal strain(GLS)in patients with right coronary artery(RCA)stenosis at different degree.To evaluate the value of 2D-STI strain in evaluating right ventricular function in patients with RCA stenosis.Methods: 20 cases normal people undergoing checkup in our hospital from December 2016 to October 2017 were as group A(normal control group).80 patients with simple RCA stenosis confirmed by coronary angiography in our hospital during the same period were as group B(lesion group).And then,the group B were divided into two groups: Group B1(40 cases with mild RCA stenosis,50% <RCA stenosis <70%),and Group B2(40 cases of severe RCA stenosis,RCA stenosis ?70%),according to the results of coronary angiography.Three groups of patients underwent conventional echocardiography and 2D-STI imaging and measurements.The parameters measured include: the tricuspid annular plane systolic excursion(TAPSE),the right-sided index of myocardial performance(RIMP),the fractional area change of right ventricle(RVFAC),the regional right ventricular longitudinal strain(S)at various segments of right ventricular wall and the global right ventricular longitudinal strain(GLS).And all the parameters are compared among the three groups.Results: General echo parameters: Compared with group A,it seems that the TAPSE and RVFAC showed a decreasing trend in group B1,but the differences were not statistically significant(both P>0.05),while RIMP increased significant(P<0.05);but in group B2,both TAPSE and RVFAC decreased and RIMP increased significant(all P<0.05).Compared with group B1,TAPSE and RVFAC decreased and RIMP increased significant in B2 group(all P<0.05).2.2D-STI parameters: Compared with group A,the S of the right ventricular wall and the GLS in both group B1 and group B2 decreased significant(P<0.05-0.001).Compared with group B1,the S of the right ventricular wall and GLS in group B2 decreased significant(P<0.01-0.001);Especially,the difference of the S of various segments of the right ventricular lateral wall and the GLS was very significant among the three groups(all P < 0.001).Conclusion: RCA stenosis at different degree could result in the decrease of the S of right ventricular wall.And the decrease of GLS and S of any segment at the right ventricular wall can reflect indirectly the presence and the degree of RCA stenosis.Furthermore,the GLS and S of right ventricular lateral wall are the most reliable parameters to evaluate the local and overall systolic function of the right ventricle in patients with RCA stenosis at different degree.