Page 155 - The role of advanced echocardiography in patients with ischemic heart disease - Rachid Abou

Conventional transthoracic echocardiography
Two-dimensional transthoracic echocardiography was performed in 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 3.5-MHz or M5S transducers. Standard M-mode, 2D, color, pulsed and continuous wave Doppler images were acquired and stored digitally for offline analysis (EchoPac BT13; GE Medical Systems, Horten, Norway). LV ejection fraction (EF) was calculated from the apical 4- and 2-chamber views using the Simpson’s biplane method.15
Two-dimensional speckle tracking echocardiography
From 2D echocardiographic data, LV global longitudinal strain (GLS) was quantified
by 2D STE from the apical 4-, 2- and long-axis views. The endocardial borders were
traced at the end-systolic frame and an automated tracking algorithm outlined the myocardium in successive frames throughout the cardiac cycle.16 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 (Figure 2). LV MD was defined as the time
from onset of the Q/R wave on the electrocardiogram to peak longitudinal strain.8 LV mechanical dispersion was defined as the standard deviation of time to peak longitudinal 8 strain in 17 LV segments and generated automatically by the software (Figure 2).
Late gadolinium contrast enhanced cardiac magnetic resonance
CMR was performed on a 1.5-T Gyroscan ACS-NT/Intera MR system or on a 3.0-T Ingenia MR system (Philips Medical Systems, Best, the Netherlands). A standardized protocol was followed, including cine CMR in long-(2- and 4-chamber views) and short- axis reconstructions. Contrast-enhanced images were acquired 15 min after bolus injection of gadolinium (Magnevist, Schering, Berlin, Germany) (0.15 mmol/kg) with an inversion-recovery 3D turbo-field echo sequence with parallel imaging. The heart was imaged in 1 or 2 breath-holds with 20 to 24 imaging levels in short-axis views.4
For image analysis, the MASS software (research version 2012, LKEB, Leiden University Medical Centre, Leiden, the Netherlands) was used for offline analysis. Myocardial scar was assessed by signal intensity. First, the endocardial and epicardial contours were traced on the short-axis images. Papillary muscles were considered as part of the ventricular cavity, and epicardial fat was excluded. Subsequently, the maximum signal intensity within the infarcted region was determined, while allowing the observer to manually override its decisions based on visual assessment. LV end-diastolic volume
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