What does a global longitudinal strain (GLS) result of -16.2% indicate and how should it be managed?

Understanding Your GLS Result of -16.2%

Your GLS of -16.2% represents borderline-to-mildly reduced left ventricular function that warrants further evaluation and monitoring, even though your cardiologist considered the overall study "normal." 1, 2

What This Number Means

• Normal GLS ranges from -18% to -22% (more negative is better), with values between -16% to -18% considered borderline, and anything above -16% (less negative) classified as abnormal 1, 3
• Your value of -16.2% falls just into the borderline-to-mildly abnormal range, indicating early subclinical left ventricular dysfunction that may not yet be apparent on standard ejection fraction measurement 2, 3
• GLS is more sensitive than ejection fraction for detecting early myocardial dysfunction, often identifying abnormalities months before EF declines 2

Why Your Cardiologist May Have Said "Normal"

• Many cardiologists focus primarily on ejection fraction (EF) as the main measure of heart function, and if your EF was preserved (≥50%), they may have considered the overall study reassuring 1, 4
• There is significant vendor variability in GLS measurements between different ultrasound machines and software versions, so some practitioners are cautious about over-interpreting borderline values 1
• The clinical context matters: in athletes or certain populations, slightly reduced GLS values can represent normal physiologic adaptation rather than pathology 1

What You Should Do Next

Confirm the measurement by repeating echocardiography with the same equipment vendor within 2-3 weeks, as vendor variability can affect absolute values 2

Implement serial GLS monitoring every 3-6 months to detect progression, as worsening GLS over time indicates pathological deterioration rather than measurement variability 2

Discuss with your cardiologist:

• Whether you have any heart failure risk factors (hypertension, diabetes, prior chemotherapy, family history of cardiomyopathy) that would make this finding more concerning 4, 5
• Whether guideline-directed medical therapy should be initiated if risk factors are present, such as ACE inhibitors/ARBs or beta-blockers 2
• The specific clinical context: recent viral illness (including COVID-19), athletic training status, or other conditions that might explain the borderline value 1

Clinical Significance and Prognosis

• In patients with heart failure with preserved ejection fraction (HFpEF), abnormal GLS (>-15.8%) predicts a 74% increased risk of cardiovascular mortality or heart failure hospitalization compared to normal GLS 5
• In aortic stenosis patients, GLS >-15% (corresponding to 95% specificity for myocardial fibrosis) identifies those with the worst outcomes 4
• Each 1% worsening in GLS (becoming less negative) is associated with 10-13% increased odds for adverse cardiovascular events 5

Important Caveats

• A single borderline value does not necessarily indicate disease, especially if you are asymptomatic, have no cardiac risk factors, and have normal ejection fraction 1
• Post-cardiac surgery patients may have artifactually reduced septal strain due to paradoxical septal motion, making the measurement less reliable 2
• Regional wall motion abnormalities can affect GLS interpretation, so the distribution of strain abnormalities matters 6

Bottom Line

Your GLS of -16.2% deserves attention and follow-up, even if other echocardiographic parameters appear normal. Request a discussion with your cardiologist specifically about this value, ask for repeat measurement to confirm accuracy, and establish a monitoring plan if the value is reproducible. This is particularly important if you have cardiovascular risk factors, symptoms, or a history of conditions that can affect heart function (chemotherapy, hypertension, viral myocarditis). 2, 5, 3