From the Guidelines
The average global longitudinal strain (GLS) value of -18% is considered normal, as it falls within the normal range of -18% to -22%. According to the European Association of Cardiovascular Imaging, a normal GLS typically ranges between -18% to -22%, with more negative values indicating better left ventricular function 1. Your value of -18% falls at the lower end of the normal range, suggesting adequate but borderline myocardial contractility. GLS measures the percentage of myocardial deformation during contraction, providing a more sensitive assessment of cardiac function than traditional ejection fraction measurements. It detects subtle changes in heart muscle function before more obvious signs of dysfunction appear. This measurement is particularly useful for monitoring patients with early cardiac disease, those receiving cardiotoxic medications, or for evaluating subclinical heart dysfunction. No specific intervention is needed for a normal GLS value, but regular cardiac follow-up is recommended if you have underlying cardiac risk factors or conditions.
Some key points to consider:
- GLS is a sensitive marker of left ventricular function, and values within the normal range indicate good cardiac function 1.
- The use of speckle tracking-derived global longitudinal strain (GLS) is recommended to provide quantitative analysis of LV longitudinal function 1.
- GLS has demonstrated to be highly feasible and reproducible in the clinical setting and provides an incremental predictive value in unselected patients undergoing echocardiography for determination of LV function at rest 1.
- In patients with heart failure, GLS can help predict readmission within 30 days and is associated with a worse prognosis 1.
Overall, a GLS value of -18% is considered normal, and no specific intervention is needed. However, regular cardiac follow-up is recommended if you have underlying cardiac risk factors or conditions.
From the Research
Global Longitudinal Strain
- The average global longitudinal strain (GLS) value is not explicitly stated in the provided studies as a single, universal average. However, various studies mention different average GLS values in different contexts:
- A study published in 2021 2 mentions a median GLS of -22.2% in a population with a normal left ventricular ejection fraction (LVEF).
- Another study from 2021 3 reports mean GLS values worsening across American Heart Association (AHA) heart failure stages, from -19.44% in stage A to -15.52% in stages C/D.
- GLS is recognized as a valuable metric for assessing cardiac function, potentially offering more sensitivity than LVEF in detecting subclinical left ventricular dysfunction 4.
- Factors associated with GLS include age, sex, obesity, atrial fibrillation, myocardial infarction, and estimated glomerular filtration rate, indicating that GLS can reflect the impact of various cardiovascular risk factors on cardiac function 3.
Clinical Implications
- GLS has been shown to provide incremental prognostic value in predicting heart failure and mortality, independent of conventional echocardiographic measures like LVEF 5, 3.
- A cut-off value of -20.0% for GLS has been suggested to identify individuals at increased risk of adverse cardiac events, although this may vary depending on the population and specific clinical context 2.
- The use of GLS in clinical practice could enhance risk stratification and guide therapeutic decisions, especially in patients with heart failure or those at risk of developing cardiac dysfunction 6, 4.