What are the recommended guidelines for acquiring and interpreting strain echocardiography (speckle‑tracking) studies?

Strain Echocardiography Guidelines

For left ventricular (LV) strain imaging, acquire apical 4-chamber and 2-chamber views with frame rates >40 Hz (ideally 50-70 Hz), optimize endocardial border visualization, avoid foreshortening, and measure global longitudinal strain (GLS) using 2D speckle-tracking echocardiography with values more negative than -18% considered normal. 1

Left Ventricular Strain Acquisition

Image Optimization

• Maximize LV cavity area in apical views while avoiding foreshortening, which artificially reduces strain values 2
• Ensure the entire LV endocardium is visible throughout the cardiac cycle
• Use contrast enhancement when two or more contiguous segments are poorly visualized 2
• Target frame rates of 50-70 Hz for optimal speckle tracking 1

Technical Requirements

• Acquire from apical 4-chamber and 2-chamber views as the standard approach 2
• Store at least 3 cardiac cycles in non-compressed format
• Ensure adequate spatial resolution without sacrificing temporal resolution
• Position the region of interest to include myocardium while excluding pericardium 2

Right Ventricular Strain Acquisition

Specific Considerations for RV

• Use RV-focused apical 4-chamber view to optimize RV visualization 2
• Ensure the entire RV free wall (base to apex) is contained within the imaging sector
• Maintain frame rates >70 Hz given the thinner RV wall 2

Critical Technical Points

• Place basal reference points on the ventricular side of the tricuspid annulus—placing them too low (atrial side) produces artifactually low strain values 2
• Limit region of interest width to the thin RV myocardium, excluding pericardium
• Be aware that image quality, reverberation artifacts, and attenuation significantly affect RV strain measurements 2

Interpretation Standards

LV Global Longitudinal Strain

• Normal values: More negative than -18% (absolute value >18%) 1
• GLS provides superior diagnostic and prognostic value compared to ejection fraction across cardiovascular disorders 1
• Detects subclinical dysfunction before ejection fraction declines 1
• Highly reproducible with less interobserver variability than ejection fraction 1

RV Free Wall Strain

• Normal values: More negative than -20% (absolute value >20%) 2
• Values less negative than -20% (absolute value <20%) indicate RV dysfunction 2
• Two reporting methods exist:
  • RV free wall strain alone (3 segments): typically -29% 2
  • RV free wall + septal strain (6 segments): typically -21% 2
• Specify which methodology you use as values differ significantly between approaches 2

Common Pitfalls and How to Avoid Them

Acquisition Errors

• Foreshortening is the most common error—actively maximize LV area in both apical views to prevent underestimation of strain 2
• Inadequate frame rate (<40 Hz) reduces tracking accuracy—prioritize temporal resolution 1
• Including pericardium in the region of interest artificially reduces strain values 2

Analysis Errors

• Vendor dependency remains significant—use vendor-specific reference values when available 3
• Poor endocardial definition requires contrast enhancement rather than accepting suboptimal tracking 2
• For RV strain, misplacing basal points on the atrial side of the annulus is a frequent technical error 2

Standardization Considerations

The EACVI/ASE/Industry Task Force established consensus definitions for strain measurements to reduce intervendor variability 3. However, absolute strain values still vary between vendors, so:

• Use the same vendor/software for serial measurements in individual patients
• Apply vendor-specific reference ranges when available
• Document the specific methodology (e.g., RV free wall alone vs. free wall + septum) 2

Clinical Applications with Prognostic Value

LV GLS has established prognostic value in:

• Heart failure (all phenotypes) 1
• Ischemic heart disease 1, 4
• Valvular disease, particularly aortic stenosis 1, 4
• Cardio-oncology for detecting cardiotoxicity 1, 4
• Cardiomyopathies and LV hypertrophy 1, 4

RV free wall strain predicts outcomes in:

• Pulmonary hypertension 2
• Acute myocardial infarction 2
• Heart failure 2
• RV failure risk after LV assist device implantation 2

Loading Conditions and Limitations

Strain measurements are load-dependent, though less so than ejection fraction 2. RV strain particularly depends on:

• RV loading conditions
• RV size and shape
• Overall heart motion (though less than TAPSE or S' velocity) 2

This load dependency should inform interpretation in acute hemodynamic changes or volume-responsive conditions.