WHAT IS GLOBAL LONGITUDINAL STRAIN AND ITS CLINICAL IMPORTANCE?

Global Longitudinal Strain (GLS) is an important parameter that reflects the deformation of the left ventricle in the longitudinal direction. In comparison with Ejection Fraction (EF) it is earlier in the detection of systolic disfunction; moreover, it is linked to prognosis in many clinical conditions.

We have three types of Strain: the longitudinal strain, the radial strain and the circumferential strain. The only parameter which is validated is the Global Longitudinal Strain. GLS is a negative value that reflects the deformation of the single segments of the left ventricle. Normal values are more negative than -20%, even though a real cut off value has not been validated since there are some differences between the different echo machine vendors. The more negative GLS is, the more normal the deformation of the left ventricle is.

It has been demonstrated that GLS could be pathologically reduced in patients with hypertension, diabetes and obesity. This is due to the pathological hypertrophy of the left ventricle. A clear example of this is hypertrophic cardiomyopathy, in which EF could be normal, but GLS is generally severely reduced.

Another application of GLS is Amyloidosis in which GLS is reduced with a typical apical sparing.

Furthermore, in severe aortic stenosis in patients with no symptoms, the reduction of GLS is associated with the rapid onset of symptoms and a worse prognosis; conversely, in severe mitral regurgitation, the reduction of GLS is associated with systolic disfunction in the post operative period.

Finally, the most important application of GLS is cardio-oncology. Indeed, in patients that undergo chemotherapy GLS is earlier in the detection of LV systolic disfunction in comparison with EF. For this reason, a reduction of GLS of more than 15% from the beginning of the therapy underlines the presence of cardiothoxicity, and, therefore, in such cases it is indicated to start cardioprotective therapies.

Please note: All echocardiographic images or videos are anonymous, and when a single case is presented written consensus of the patient has been collected for the publication of the images.

Видео WHAT IS GLOBAL LONGITUDINAL STRAIN AND ITS CLINICAL IMPORTANCE? канала Sergio Suma