What is the clinical significance of a Global Longitudinal Strain (GLS) of -16.2?

From the Guidelines

A Global Longitudinal Strain (GLS) value of -16.2% indicates mild left ventricular systolic dysfunction, as it falls slightly below the normal range, suggesting early subclinical myocardial dysfunction that may not be detected by conventional ejection fraction measurements. Normal GLS values are typically more negative than -18% to -20%, with more negative numbers representing better cardiac function 1. This mild impairment suggests that the patient may be at risk of developing more severe cardiac dysfunction if left untreated. Clinical management should include identifying potential causes such as hypertension, coronary artery disease, or cardiomyopathy. Further cardiac evaluation with additional imaging or functional tests may be warranted to determine the underlying cause of the reduced GLS.

Key Considerations

• Regular follow-up monitoring of GLS is recommended to track progression, typically every 6-12 months depending on clinical context 1.
• GLS is particularly valuable because it can detect subtle changes in cardiac function before ejection fraction decreases, allowing for earlier intervention.
• The -16.2% value represents the average percentage of myocardial shortening during systole measured in the longitudinal direction, with the negative sign indicating shortening of the myocardium during contraction.

Clinical Implications

• The patient's GLS value of -16.2% is slightly below the normal range, indicating mild left ventricular systolic dysfunction.
• This condition may be associated with an increased risk of adverse cardiac events, such as heart failure or arrhythmias.
• Early detection and treatment of the underlying cause of the reduced GLS may help to prevent or delay the progression of cardiac dysfunction.

Recommendations

• Clinical management should prioritize identifying and addressing potential causes of the reduced GLS, such as hypertension or coronary artery disease.
• Further cardiac evaluation with additional imaging or functional tests may be warranted to determine the underlying cause of the reduced GLS.
• Regular follow-up monitoring of GLS is recommended to track progression and adjust treatment as needed.

From the Research

Clinical Significance of Global Longitudinal Strain (GLS) of -16.2

• The clinical significance of a GLS of -16.2 can be understood by referring to the normal range of LV global longitudinal strain (GLS), which has been defined as -18% and lower (ie more negative), abnormal as -16% or higher (ie less negative), with -16 to -18% being borderline 2.
• A GLS of -16.2 falls into the borderline category, indicating that left ventricular function may be slightly impaired but not severely abnormal.
• The prognostic value of GLS has been demonstrated in various studies, including its ability to predict cardiovascular events in patients with normal LVEF 3 and its association with symptom onset and the need for aortic valve intervention in patients with asymptomatic severe aortic stenosis 4.
• In patients with ST-segment elevation myocardial infarction and preserved systolic function, a baseline GLS value of >-12.65% has been shown to predict 30-day major adverse cardiac events (MACEs) 5.
• The time course evolution of GLS has also been studied in patients with septic shock, showing that myocardial strain is depressed at the early phase of septic shock and improves over time 6.

Implications of a GLS of -16.2

• A GLS of -16.2 may indicate mild left ventricular dysfunction, which could be a precursor to more severe cardiac disease.
• Patients with a GLS of -16.2 should be closely monitored for signs of cardiac dysfunction and may benefit from regular echocardiographic assessments to track changes in left ventricular function.
• The borderline GLS value of -16.2 highlights the importance of considering GLS in conjunction with other clinical and echocardiographic parameters to accurately assess cardiac function and guide management decisions.