Validation of Speckle tracking Strain Measurements as an Accurate and Reproducible Technique for detecting Global and Segmental Myocardial Deformation

摘要

Background: Myocardial deformation analysis particularly longitudinal strain (LS) measurement, byspeckle tracking echocardiography (STE) has been proposed to provide improved evaluation of both global andsegmental myocardial function.Aim: Our aim was to study the feasibility, reproducibility and accuracy of global and segmental LSfrom STE as compared with left ventricular segmental wall motion score (SWMS) by two dimensionalechocardiography (2DE).Methods: 2DE and STE was performed in 40 individual, 29 males with mean age of 59.4±13.6 years.Study population included 2 groups, (GI) 20 patients with ischemic heart disease and (GII) 20 healthy volunteerswith matched age and sex. 2DE and STE were performed with Vivid 7 system (GE healthcare, USA).Quantitative segmental STE LS was analyzed by 2 different experienced blinded observers using the Echopacsoftware. In addition segmental wall motion score (SWMS) from the 2DE images was performed by twoindependent observer for comparison. The 17 segments model was used for analysis of both modalities.Results: Left ventricular ejection fraction by biplane modified Simpson’s method was 49.9±15% forthe whole population, while it was 41.9±14.1% and 58.2±11.1% for GI and GII respectively. STE-LS analysis isfeasible and was found to improve segmental myocardial visualization for analysis as it reduced the noninterpretable segments to 15/680 (2%) as compared to 25/680 (4%) by 2DE-SWMS (p=0.00). This was moreevident for basal lateral segment (non adequate segments reduced to 4 by STE-LS as compared to 10 for 2DESWMS).Global STE strain was -11.8±6.7, (GI= -9.3±7.1 and GII= -15±3.7, p=0.02). While global 2DE-SWMSanalysis was 20.6±6.4 (GI=24.9±6.4 and GII=16.0±0.0, P=0.0001. Inter-observer variability of segmental STEstrain were (-0.02±2.0, -0.0±2.3 and -0.0±1.9 for all study population, GI and GII respectively) these were foundto be less than that of 2DE-SWMS (-2.1±5.9, -2.4±5.9 and -1.7±5.9 respectively. STE-LS had excellentcorrelation with SWMA for the whole group (r=99), for GI (R=98) and for GII (r=99).Conclusions: Assessment of STE-LS is feasible and provides an accurate technique for calculatingglobal and segmental myocardial deformation as compared with 2DE-SWMS. STE-LS have better segmentalmyocardial visualization with less observer variability as compared to 2DE-SWMS.