Speckle-Tracking Strain Echocardiography for the Assessment of Left Ventricular Structure and Function: A Scientific Statement From the American Heart Association.

Assessment of left ventricular systolic function is essential for diagnosing and managing cardiac diseases and provides important prognostic information to the treating clinician. However, traditional methods for assessing left ventricular systolic function such as ejection fraction are limited by their reliance on geometric assumptions, subjective reader interpretation, sensitivity to loading conditions and volume, and reflection of a single plane of motion. In addition to interobserver and intraobserver variability and technical confounders, this evaluation is complicated by the complex 3-dimensional organization of the myocardial fibers, which are oriented longitudinally in the subendocardium, transversely in the midmyocardium, and obliquely in the subepicardium. Conversely, 2-dimensional speckle-tracking echocardiography measures left ventricular deformation as myocardial strain in the 3 planes of chamber motion: longitudinal, circumferential, and radial. From a clinical perspective, left ventricular global longitudinal strain offers superior diagnostic and prognostic value across the spectrum of cardiovascular disorders compared with ejection fraction, is highly reproducible, and detects subclinical dysfunction before the ejection fraction declines. Given the expanding clinical utility of speckle-tracking echocardiography and the incremental prognostic and therapeutic value of integrating global longitudinal strain into clinical practice as a potential biomarker, the objectives of this scientific statement are (1) to review the principles and technical aspects of speckle-tracking echocardiography strain imaging; (2) to provide a practical, evidence-based review of the application of speckle-tracking echocardiography in heart failure, cardiomyopathies, ischemic heart disease, valvular disease, and cardio-oncology; (3) to explore the potential utility of speckle-tracking echocardiography in cardiac resynchronization and implantable cardioverter defibrillator therapy; and (4) to outline the future directions of speckle-tracking echocardiography.