RESUMO
Background: speckle tracking echocardiography [STE] enables objective assessment of left ventricular [LV] function through analysis of myocardial strain and strain rate. This study aims to determine the sensitivity and specificity of global longitudinal strain [GLS] and global longitudinal strain rate [GLSR] of LV in assessment of myocardial Jirnction compared to peak wall motion score index [WMSI] at dobutamine stress echocardiography [DSE]
Methods: fifty patients with suspected or known myocardial ischemia were evaluated by conventional echocardiography, DSE, STE and coronary angiography [CA]. Standard apical views were wed to calculate GLS and GHR by STE. WMSI was calculated at peak stress during DSE. Significant coronary lesion[s] were indicated by >/= 50% luminal stenosis in CA
Results: GLS and GLSR were significantly lower in patients with significant CAD than those with = 50% coronary lesions or normal CA. Both GLS and GLSR were shown to have moderate negative correlation with peak WMSI [r=0.467, p-value=0.001** and r=- 0.51, p-value < 0.001 *** respectively]. The diagnostic accuracy for detection of significant coronary artery disease [CAD] as determined by area under the curve [AUC] was higher for DSE [0.921] than either GLS [0.752], or GLSR [0.74]. However, this difference reached statistical significance only between DSE and GLSR [p-value = 0.03 7*]
Conclusion: GLS and GLSR are negatively correlated to peak WMSI. Both deformation parameters can predict significant lesion[s] in CA, but with lower diagnostic accuracy than DSE