What does a global longitudinal strain of -8.00% on an echocardiogram (echo) mean?

Global Longitudinal Strain of -8.00% on Echo Indicates Severe Cardiac Dysfunction

A global longitudinal strain (GLS) value of -8.00% on echocardiography indicates severe myocardial dysfunction with significantly increased risk of adverse cardiovascular outcomes, even if ejection fraction appears preserved. 1

Understanding Global Longitudinal Strain

Global longitudinal strain is a sensitive measure of myocardial deformation that detects subclinical cardiac dysfunction before changes in ejection fraction become apparent. It measures the percentage of myocardial shortening during systole:

• Normal GLS: More negative than -18% 1, 2
• Borderline GLS: Between -16% and -18% 2
• Abnormal GLS: Less negative than -16% 2
• Severely abnormal GLS: Less negative than -10% 3

Clinical Significance of GLS -8.00%

At -8.00%, this GLS value represents:

• Severe myocardial dysfunction: Values worse than -10% are associated with a 4-fold increased risk of adverse cardiovascular events compared to values better than -16% 3
• Poor prognosis: This level of strain impairment predicts higher rates of:
  • Heart failure hospitalizations 4, 5
  • Ventricular arrhythmias 6
  • Cardiovascular death 5
  • All-cause mortality 6

Potential Underlying Conditions

A GLS of -8.00% may indicate:

1. Advanced cardiomyopathy: Particularly in hypertrophic, dilated, or infiltrative cardiomyopathies 6
2. Significant coronary artery disease: Even with preserved ejection fraction 4
3. Heart failure: Especially HFpEF (heart failure with preserved ejection fraction) 6, 5
4. Valvular heart disease: Particularly aortic stenosis or mitral regurgitation 6, 7
5. Cardiotoxicity: From chemotherapy or other medications 1

Clinical Implications and Management

This severely abnormal GLS value warrants:

• Comprehensive cardiac evaluation: Including assessment of symptoms, other cardiac imaging, and biomarkers
• Identification of underlying etiology: Through additional testing such as coronary angiography, cardiac MRI, or myocardial biopsy if appropriate
• Close monitoring: More frequent follow-up echocardiography to track progression
• Early intervention: Consider appropriate medical therapy based on underlying condition
• Risk stratification: For adverse cardiovascular events and consideration of device therapy if appropriate

Important Caveats

• Vendor variability: Ensure serial measurements use the same equipment 1
• Image quality: Poor image quality can affect accuracy of strain measurements 1
• Loading conditions: GLS can be affected by loading conditions and heart rate 1
• Context matters: Interpret GLS in conjunction with other clinical and echocardiographic parameters

This severely reduced GLS value (-8.00%) should prompt urgent clinical attention as it indicates significant myocardial dysfunction that may precede overt clinical deterioration, even if conventional parameters like ejection fraction appear relatively preserved.