Introduction: Myocardial longitudinal tissue velocity imaging (TVI) and strain rate imaging (SRI) indices may have a role in the prediction of significant proximal stenosis of left anterior descending (LAD) by echocardiography. Materials And Methods: Total 20 patients with proximal LAD stenosis >70% by angiography and ejection fraction ≥50%, without wall motion abnormality at resting echo (stenotic group) and 20 angiographically normal coronaries subjects with normal echocardiography (non-stenotic group) were included in the study. SRI and TVI were performed in nine segments of the LAD territory at rest. Parameters of interest included: peak systolic strain (ST, %), strain rate (SR, Second-1), and peak systolic velocity (Sm, cm/s). Results: Overal mean ST and SR showed a significant reduction in the stenotic group compared to non-stenotic group (P<0.001), while the mean Sm had no significant difference. A segment-by-segment comparison revealed a reduction of ST in 4/9 (two apical and two anteroseptal) and SR in 5/9 (three apical, septal, and anteroseptal midportion) in the stenotic group (P<0.05). Both ST and SR showed a significant reduction in three segments: anterior-apical, lateral-apical, and anteroseptal-midportion. When both ST and SR decreased in one segment, specificity and sensitivity for the diagnosis of proximal LAD stenosis was more than 80% and 55%, respectively, by Roc analysis. Conclusion: There is an overall reduction in the mean ST and SR in the segments of LAD territory with significant proximal stenosis and normal wall motion at rest and an acceptable specificity and sensitivity of SRI for the detection of stenosis in these segments.
The tissue velocity imaging and strain rate imaging in the assessment of interatrial electromechanical conduction in patients with sick sinus syndrome before and after pacemaker implantation
