Speckle Tracking 2D Echocardiography (STE) - Interpretation Guide

1. What is Speckle Tracking?

2. Advantages over Tissue Doppler Imaging

3. Planes and Types of Strain

4. Normal Values (WASE Study, 2022)

• Textbook of Clinical Echocardiography, Table A-4

5. The Bulls-Eye (17-Segment) Plot

• Dark red = normal strain (values around -20% to -26%)
• Light red / pink / white = reduced/abnormal strain
• The outer ring = basal segments; middle ring = mid segments; inner ring = apical segments

6. How to Interpret Strain Waveforms

• Rapid decrease (negative) during systole (end-diastole to end-systole) = myocardial shortening
• Peak negative value at end-systole = peak systolic strain
• Rapid return toward zero in early diastole
• Small negative deflection in late diastole after atrial contraction (A wave)

• Reduced/absent negative strain in the affected territory
• Delayed or absent peak (post-systolic shortening is a hallmark of ischemia)

7. Key Clinical Applications

A. LV Systolic Function Assessment

• GLS detects subclinical LV dysfunction before LVEF drops - this is its most important clinical role
• A GLS less negative than -16% in the setting of preserved LVEF suggests subclinical cardiomyopathy

B. Cardio-Oncology (Chemotherapy Monitoring)

• A relative reduction in GLS >15% from baseline (e.g., from -21.6% to -17.0%) is an early marker of cardiotoxicity, even when LVEF remains normal
• Detects early cardiotoxicity from anthracyclines, trastuzumab, etc.

• Fuster and Hurst's The Heart, 15th Ed., Fig. 74-2

C. Differential Diagnosis of Cardiomyopathies

D. Dyssynchrony Assessment

• STE can quantify intraventricular dyssynchrony by measuring the time difference to peak negative strain across different segments
• Relevant for CRT (cardiac resynchronization therapy) candidacy and response evaluation

E. Diastolic Function

• Regional strain rate patterns can evaluate diastolic mechanics (impaired relaxation affects early diastolic strain rate)
• Reduced early diastolic strain rate is a marker of impaired LV relaxation

F. Right Ventricular (RV) Strain

• RV free wall longitudinal strain (RVFWLS) is emerging as a sensitive RV function parameter
• Normal RV free wall strain: typically more negative than -20% (vendor-specific)
• An RV free wall strain less negative than -20% suggests RV dysfunction (prognostic in pulmonary hypertension, PE, RV failure)

G. Myocardial Twist and Torsion

• The LV normally shows base rotating clockwise and apex counterclockwise (when viewed from apex)
• Torsion = the net wringing motion
• STE can quantify this; impaired untwisting in early diastole is a sensitive marker of diastolic dysfunction

8. Technical Requirements and Limitations

• High frame rate required (50-90 fps for 2D STE)
• Good image quality with clear endocardial border definition
• Harmonic imaging improves speckle quality
• Avoid foreshortened views
• ECG gating is essential

• Vendor-specific software (values not directly interchangeable between platforms; correction factors exist but are imperfect)
• Frame rate dependence
• Poor acoustic window degrades tracking quality
• Motion artifacts (respiratory, probe movement)
• Algorithm may fail in very dilated or hypertrophied ventricles
• 2D STE is affected by out-of-plane motion (3D STE addresses this)

9. Practical Interpretation Checklist

1. Check image quality - can you trace endocardial border cleanly?
2. Review frame rate - ideally 50-90 fps
3. Accept or reject segments - most software allows per-segment quality grading; use ≥14/16 acceptable segments for reliable GLS
4. Look at the bulls-eye - identify regional vs global pattern
5. GLS value - note whether more or less negative than -18% to -20%
6. Compare to baseline - a relative drop >15% is clinically significant in serial monitoring
7. Correlate with LVEF - reduced GLS with preserved EF = subclinical dysfunction
8. Check strain curves - look for post-systolic shortening (ischemia pattern)

Recent Guideline Update (2025)