Page 38 - The role of advanced echocardiography in patients with ischemic heart disease - Rachid Abou

Chapter two. Level and Layer Specific Left Ventricular Longitudinal Strain
data without prior approval of an institutional review board provided that the data is acquired for routine patient care. All data used for this study was acquired for clinical purposes and handled anonymously.
Images were obtained with patients at rest in the left lateral decubitus position using commercially available ultrasound systems (Vivid 7 and E9; General Electric Vingmed, Horten, Norway). Data acquisition was performed with a 3.5-MHz or M5S transducers. Standard M-mode, 2-dimensional (2D), color, pulsed and continuous wave Doppler images were acquired and stored digitally for subsequent offline analysis (EchoPac BT13; GE Medical Systems, Horten, Norway). LVEF was calculated using the Simpson’s biplane method of discs according to current recommendations.5 LV mass was calculated according Devereux et al, and indexed for body surface area.5 Valvular morphology and function were assessed with 2D, color and pulsed and continuous wave Doppler echocardiography.6 Left ventricular diastolic function was assessed by measuring the peak early (E) and late (A) diastolic velocities on transmitral flow pulsed-wave recordings. The average of E´ septal and E´ lateral measured in the apical 4-chamber view on tissue Doppler imaging was used for this analyses.7 Right ventricular (RV) function was evaluated according to current recommendations, by measuring the tricuspid annular plane systolic excursion (TAPSE) in the apical 4-chamber view using the M-mode.8 Systolic pulmonary artery pressure was estimated by adding the RV pressure to right atrial pressure. The RV pressure was estimated by calculating the systolic pressure gradient between the RV and right atrium by the peak velocity of the regurgitant jet of the tricuspid valve (if present) using the modified Bernoulli equation.8 Right atrial pressure was estimated by measuring the diameter and the inspiratory collapse of the inferior vena cava.8
From the apical 4-, 2- and long-axis views, 2-dimensional STE was applied to analyse longitudinal strain at 3 different LV levels (apex, mid, basal) and 3 different LV layers (endocardial, mid-myocardial and epicardial). The endocardial border was manually traced at end-systole and the region of interest including the entire LV myocardial wall was displayed.9 The software automatically tracks and accepts segments of good tracking quality and rejects poorly tracked segments, while allowing the observer to manually override its decisions based on visual assessment of tracking quality. Global LV longitudinal strain was obtained as the average of longitudinal strain of 17 segments (Figure 1). Subsequently, longitudinal strain values of the apex, mid and basal levels of the LV were obtained by averaging the value of strain of the 5 apical segments and the 6 basal and 6 mid ventricular segments (Figure 2). Finally, the software allows for analysis of the LV longitudinal strain of the 3 different layers: endomyocardial, mid-myocardial and epicardial. Layer-specific longitudinal strain values are obtained as the average of
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