Ten Years of 2D Longitudinal Strain for Early Myocardial Dysfunction Detection: A Clinical Overview

Abstract

In recent years, the role of left ventricular ejection fraction (EF) as the gold standard parameter for the evaluation of systolic function has been questioned, and many efforts have been concentrated in the clinical validation of new noninvasive tools for the study of myocardial contractility. Improvement in the accuracy of speckle-tracking echocardiography has resulted in a large amount of research showing the ability of two-dimensional strain to overcome EF limitations in the majority of primary and secondary heart diseases. Currently, global longitudinal strain (GLS) is considered the most accurate and sensitive parameter for the assessment of early left ventricular dysfunction. This review summarizes the advantages that this measurement can provide in several clinical settings. Moreover, the important cautions that should be considered in making the choice to use GLS also are addressed. Finally, a special focus on bull's-eye polar maps for the assessment of regional changes of longitudinal function and the usefulness of these maps in the differential diagnosis of several diseases is provided.

Figure 1

Echocardiographic assessment of left ventricular systolic function in a healthy subject through three-dimensional ejection fraction (a) and two-dimensional speckle-tracking echocardiography global longitudinal strain curves and bull's-eye map (b).

Figure 2

Bull's-eye maps of global longitudinal strain depicting different patterns of left ventricular hypertrophy: (a) athlete, (b) hypertension, (c) aortic stenosis with hypertrophy of basal segments, (d) heart failure with preserved ejection fraction and diffuse left ventricle hypertrophy, (e) hypertrophic cardiomyopathy, and (f) amyloidosis with classical “apical sparing” pattern.

Figure 3

Clinical case of a 47-year-old man with amyloidosis. Please note left ventricular hypertrophy with paracardiac pathological tissue (Panels (a)-(c)) and diastolic dysfunction as assessed by mitral peak early (e) and late (a) velocities restrictive pattern (E/A > 2) with lowest, almost zero, A wave amplitude suggestive of atrial impairment (Panel (d)). Panel (e) shows left ventricular two-dimensional speckle-tracking echocardiography longitudinal strain curves and bull's-eye map with typical “apical sparing” pattern (Panel (e)).

Figure 4

Echocardiographic assessment of postinfarction left ventricular remodeling through two-dimensional speckle-tracking echocardiography longitudinal strain bull's-eye maps in one patient with anterior myocardial infarction (a) and in another with inferior myocardial infarction (b). Red/blue bull's-eye maps (a, b) clearly identify regional alterations of longitudinal strain in the segments more affected by myocardial infarction (thin and dilated), whereas green/yellow bull's-eye maps (c, d) describe delayed activation (yellow and red areas) in the same segments, which can determine mechanical dispersion and increased risk of arrhythmias.

Figure 5

Comparison between global longitudinal strain and cardiac magnetic resonance imaging in two patients with (a) anterior myocardial infarction and (b) inferior myocardial infarction. The infarct areas of the bull's-eye map correspond closely with late gadolinium enhancement (scar) areas on magnetic resonance imaging.

Figure 6

A 27-year-old male patient with myocarditis. Panel A1-3 shows normal left ventricular systolic function assessed by Simpson's method. Panel B shows left ventricular two-dimensional speckle-tracking echocardiography longitudinal strain curves and bull's-eye map: please note that the bull's-eye plot underlines regional alterations of longitudinal function in the inferolateral wall. In Panel C1-2, cardiac magnetic resonance shows a hyperenhancement area located in the epicardial layer of the inferior and inferolateral left ventricular walls, suggesting edema and fibrosis, respectively, on both T2 weighted and late gadolinium enhancement images; please note that bull's-eye data from two-dimensional speckle-tracking echocardiography are confirmed by the assessment of fibrosis in the same segments by cardiac magnetic resonance.

Figure 7

Assessment of left ventricular systolic function through two-dimensional Simpson's method and global longitudinal strain curves with bull's-eye plots in two patients undergoing chemotherapy with mild (a) and severe (b) left ventricular dysfunction. Please note that in the first case (a) ejection fraction is normal (58%) whereas global longitudinal strain is mildly impaired (-18.2%) with some regional areas of early damage and that, in the second case (b), although the ejection fraction is only at low limits (51%), global longitudinal strain is severely reduced (-9.4%) with an extensive regional impairment, as shown in the bull's-eye plots.