Speckle tracking echocardiography
1. What is the primary parameter measured in speckle tracking echocardiography?
A. Myocardial strain
B. Ejection fraction
C. Cardiac output
D. Pulmonary artery pressure
Speckle tracking primarily measures myocardial strain, providing detailed insight into myocardial mechanics beyond traditional EF.
2. Which type of strain is most commonly reported in speckle tracking?
A. Global longitudinal strain (GLS)
B. Radial strain
C. Circumferential strain
D. Torsional strain
GLS is the most widely used parameter in speckle tracking, sensitive for detecting subtle LV dysfunction.
3. What is the normal range for GLS in a healthy adult?
A. -10% to -12%
B. -18% to -22%
C. -25% to -30%
D. 0% to -8%
Normal GLS typically falls between -18% to -22%, with more negative values indicating better function.
4. Which condition is most sensitively detected by reduced GLS before EF drops?
A. Severe aortic stenosis
B. Chemotherapy-induced cardiotoxicity
C. Pericarditis
D. Patent foramen ovale
GLS is sensitive in detecting early myocardial dysfunction from cardiotoxic drugs, often before EF changes.
5. Which software method is used to track speckles in the myocardium?
A. Doppler velocity tracking
B. 2D grayscale pattern recognition
C. M-mode scanning
D. Tissue harmonic imaging
Speckle tracking uses 2D grayscale pattern recognition to follow natural acoustic markers in the myocardium.
| No. | Key Point | Detailed Explanation |
|---|---|---|
| 1 | Definition | Speckle Tracking Echocardiography (STE) is an advanced echocardiographic technique that tracks natural acoustic markers (“speckles”) in the myocardium on 2D ultrasound images to measure myocardial deformation (strain and strain rate) without relying on Doppler angles. |
| 2 | Key Measurement | Global Longitudinal Strain (GLS) is the most widely used STE parameter, reflecting average deformation of the left ventricle in the longitudinal plane. Normal GLS is typically around -18% to -22%, with less negative values indicating impaired function. |
| 3 | Angle Independence | Unlike Doppler-based strain, STE is largely angle-independent, allowing more accurate assessment of myocardial deformation from standard 2D images without strict alignment to the ultrasound beam. |
| 4 | Frame Rate | Optimal frame rate for STE is generally between 40–90 frames per second. Too low causes temporal resolution issues, and too high may compromise spatial resolution. |
| 5 | Applications in Cardiotoxicity | STE is crucial for early detection of chemotherapy-induced cardiotoxicity. A relative drop in GLS >15% from baseline is considered significant and may occur before ejection fraction declines. |
| 6 | Ischemic Heart Disease | STE can identify regional strain abnormalities corresponding to coronary artery territories, enabling detection of subtle myocardial dysfunction even when EF is preserved. |
| 7 | Heart Failure with Preserved EF | Patients with HFpEF may have abnormal GLS despite normal EF, making STE a sensitive diagnostic tool for subclinical systolic dysfunction. |
| 8 | Valvular Heart Disease | STE aids in risk stratification in aortic stenosis and mitral regurgitation by detecting early LV dysfunction, guiding surgical timing before EF falls. |
| 9 | Right Ventricular Strain | STE can quantify RV free wall strain, which is important in pulmonary hypertension, RV infarction, and congenital heart disease follow-up. |
| 10 | Atrial Strain | STE-derived atrial strain provides insight into left atrial function, fibrosis, and risk of atrial fibrillation recurrence after ablation. |
| 11 | 3D Speckle Tracking | Three-dimensional STE offers more comprehensive volumetric strain assessment and reduces dependency on geometric assumptions, though it requires higher image quality. |
| 12 | Vendor Variability | Differences in algorithms between ultrasound manufacturers can cause inter-vendor variability in strain measurements, limiting interchangeability of values across machines. |
| 13 | Load Dependence | Strain values are affected by preload and afterload conditions, so clinical interpretation must consider hemodynamic status at the time of measurement. |
| 14 | Normal Reference Ranges | GLS normal range is approximately -18% to -22% for the LV, while RV free wall strain is normally less than -20%. Reference values may vary with age, sex, and body habitus. |
| 15 | Post-MI Risk Stratification | STE detects reduced strain in infarcted and peri-infarct zones, predicting LV remodeling and arrhythmia risk more effectively than EF alone. |
| 16 | Cardiomyopathies | STE patterns help differentiate hypertrophic, restrictive, and dilated cardiomyopathies by showing characteristic strain distribution and timing abnormalities. |
| 17 | Dyssynchrony Assessment | STE can quantify mechanical dyssynchrony in heart failure patients considered for cardiac resynchronization therapy, aiding selection and optimization. |
| 18 | Exercise and Stress Testing | Strain imaging during stress echocardiography increases sensitivity for detecting ischemia, especially in borderline cases with wall motion abnormalities. |
| 19 | Pediatric and Congenital Uses | STE is valuable in assessing myocardial performance in children with congenital heart disease, cardiomyopathies, and post-surgical follow-up. |
| 20 | Future Directions | Integration of artificial intelligence, automated border tracking, and fusion with other imaging modalities (CT, MRI) may improve reproducibility and clinical impact of STE. |
