Should LVEF be replaced by global longitudinal strain?

For many years, echocardiography remained the main non-invasive bedside-imaging modality to provide reliable assessment of cardiac mechanics. Considering its major prognostic value, vigorous efforts were made to improve ultrasound determination of global left ventricular (LV) systolic function, from M-mode fractional shortening to Simpson's biplane or 3D ejection fraction (EF). However, these volumetric indices of global LV showed inherent variability, influenced by image quality, off-axis imaging or measurement errors. Direct echocardiographic assessment of myocardial fibre deformation has recently become available in routine clinical practice with the development of speckle-tracking imaging software. This relatively new technique is based on frame-to-frame tracking of acoustic markers (speckles) obtained from gray-scale echocardiographic images. However, significant variability was observed within the first generation of software products released by various manufacturers, mostly related to vendor-specific postprocessing algorithms.1 While ongoing efforts from vendors and echocardiographic societies are designed to standardise and calibrate strain measurements, a high level of agreement and reproducibility has recently been reported for global (but not segmental) longitudinal strain (GLS) obtained with the most …