Speckle-tracking analysis based on 2D echocardiography does not reliably measure left ventricular torsion

Left Ventricular Twist and the "Rigid Body Rotation" Pattern in Patients Treated with Anthracyclines or Anti-HER2

Background: During the physiological cardiac cycle, the helix orientation of the muscle fibres induces the rotation of the apex relative to the base of the left ventricular (LV). In heart failure, LV torsion is impaired, and rotation at basal and apical levels occurs in the same direction, a phenomenon called rigid body rotation (RBR). We aimed to evaluate whether the RBR pattern and GLS together could improve the diagnosis of cardiotoxicity in patients treated with anthracyclines and/or anti-HER2. Methods: With an observational, retrospective study involving 175 patients (mean age 55 ± 12 years, 94% females), we evaluated the development of cancer therapeutic-related cardiac dysfunction (CTRCD) defined according to ESC guidelines. We characterised LV dysfunction by echocardiographic standard and speckle-tracking (GLS and RBR pattern) measurements. Patients with a previous diagnosis of structural heart disease or atrial fibrillation were excluded. Results: At the time of enrolment, the chemotherapy regimen included trastuzumab (96%), pertuzumab (21%), and anthracyclines (13%). Twenty-two patients (12.5%) developed cardiotoxicity, and thirteen patients developed an RBR within 6 months of follow-up. In all cases, the RBR pattern was associated with cardiotoxicity (p < 0.001), reporting an optimal specificity but poor sensitivity at three and six months. However, the addition of the RBR pattern to the global longitudinal strain (GLS) ≥ -16% increased the odds ratio (OR) from 25.6 to 32.6 at three months and from 32.5 to 49.6 at six months rather than GLS alone. Conclusions: The RBR pattern improves the diagnostic accuracy of GLS for the detection of cardiotoxicity secondary to anthracyclines and anti-HER2-based treatments.

Impact of aortic valve stenosis on myocardial deformation in different left ventricular levels: A three-dimensional speckle tracking echocardiography study

BACKGROUND

Global systolic left ventricular (LV) myocardial function progressively declines as degenerative aortic valve stenosis (AS) progresses. Whether this results in uniformly distributed deformation changes from base to apex has not been investigated.

METHODS

Eighty-five AS patients underwent three-dimensional (3D) echocardiography in this cross-sectional study. Patients were grouped by peak jet velocity into mild (n = 32), moderate (n = 31), and severe (n = 22) AS. 3D speckle tracking derived strain, rotation, twist, and torsion were obtained to assess global LV function and myocardial function at the apical, mid, and basal levels.

RESULTS

Global longitudinal strain (GLS) was lower in patients with severe AS (-16.1 ± 2.4% in mild, -15.5 ± 2.5% in moderate, and -13.5 ± 3.0% in severe AS [all p < .01]). Peak basal and mid longitudinal strain (LS), basal rotation and twist from apical to basal level followed the same pattern, while peak apical LS was higher in moderate AS compared to severe AS (all p < .05). In multivariate analyses, lower GLS was particularly associated with male sex, higher body mass index and peak aortic jet velocity, lower basal LS with higher filling pressure (E/e') and LV mass, lower mid LS with higher RWT and presence of AS symptoms, and lower apical LS with male sex and higher systolic blood pressure, respectively (all p < .05).

CONCLUSION

Using 3D speckle tracking echocardiography reveals regional and global changes in LV mechanics in AS related to the severity of AS, LV remodeling and presence of cardiovascular risk factors.

Early myocardial changes in patients undergoing rheumatic mitral valve repair versus replacement

BACKGROUND

Rheumatic mitral valve repair and replacement techniques are frequently used with excellent outcomes in experienced centers. This study aims to evaluate the impact of procedural types on left ventricular function in quinquagenarians.

METHODS

Between January 2018 and September 2019, patients with severe rheumatic mitral stenosis were prospectively recruited. Propensity score matching was performed to reduce the selection bias. We compared the strain, twist and synchrony parameters of left ventricle in 70 quinquagenarian patients who underwent rheumatic mitral valve repair and replacement 12 hours before surgery, at 7 days and 6 months postoperatively.

RESULTS

The overall group displayed significant improvement of left ventricular deformation after rheumatic mitral valve surgery. Compared with patients undergoing posterior chordal-sparing mitral valve replacement, patients undergoing rheumatic mitral valve repair showed more significant amelioration in global longitudinal strain (-18.6% versus -16.2%, P<0.001), twist (18.2° versus 15.9°, P<0.001), torsion (1.8°/cm versus 1.3°/cm, P<0.001), apical rotation (10.5° versus 8.8°, P<0.001), basal rotation (-7.7° versus -7.1°, P=0.049), systolic dyssynchrony index (4.7% versus 5.1%, P=0.021), standard deviation of time to peak longitudinal (46.9 ms versus 49.3 ms, P=0.024) and radial strain (15.8 ms versus 17.1 ms, P=0.037) at 6-month follow-up.

CONCLUSIONS

Rheumatic mitral valve repair might provide patients with better postoperative left ventricular performance than posterior chordal-sparing mitral valve replacement. Longer follow-up is required to compare long-term outcomes.

A left ventricular phantom for 3D echocardiographic twist measurements

Traditional two-dimensional (2D) ultrasound speckle tracking echocardiography (STE) studies have shown a wide range of twist values, also for normal hearts, which is due to the limitations of short-axis 2D ultrasound. The same limitations do not apply to three-dimensional (3D) ultrasound, and several studies have shown 3D ultrasound to be superior to 2D ultrasound, which is unreliable for measuring twist. The aim of this study was to develop a left ventricular twisting phantom and to evaluate the accuracy of 3D STE twist measurements using different acquisition methods and volume rates (VR). This phantom was not intended to simulate a heart, but to function as a medium for ultrasound deformation measurement. The phantom was made of polyvinyl alcohol (PVA) and casted using 3D printed molds. Twist was obtained by making the phantom consist of two PVA layers with different elastic properties in a spiral pattern. This gave increased apical rotation with increased stroke volume in a mock circulation. To test the accuracy of 3D STE twist, both single-beat, as well as two, four and six multi-beat acquisitions, were recorded and compared against twist from implanted sonomicrometry crystals. A custom-made software was developed to calculate twist from sonomicrometry. The phantom gave sonomicrometer twist values from 2.0° to 13.8° depending on the stroke volume. STE software tracked the phantom wall well at several combinations of temporal and spatial resolution. Agreement between the two twist methods was best for multi-beat acquisitions in the range of 14.4–30.4 volumes per second (VPS), while poorer for single-beat and higher multi-beat VRs. Smallest offset was obtained at six-beat multi-beat at 17.1 VPS and 30.4 VPS. The phantom proved to be a useful tool for simulating cardiac twist and gave different twist at different stroke volumes. Best agreement with the sonomicrometer reference method was obtained at good spatial resolution (high beam density) and a relatively low VR. 3D STE twist values showed better agreement with sonomicrometry for most multi-beat recordings compared with single-beat recordings.

Correlation and agreement between 2D and 3D speckle-tracking echocardiography for left ventricular volumetric, strain, and rotational parameters in healthy volunteers and in patients with mild mitral stenosis

BACKGROUND

Recent advances had allowed measurement of myocardial deformation parameters using 3D speckle-tracking echocardiography (STE). Agreement between these two modalities and interchangeability of findings remain as an issue since 2DSTE is more widely available than 3DSTE. The aim of this study was to investigate the correlation and agreement between 2DSTE and 3DSTE in healthy volunteers and in patients with mild mitral stenosis (MS).

METHODS

Data from 31 patients with mild MS and 27 healthy volunteers were included in this study. Data were analyzed for the correlation and agreement between 2DSTE and 3DSTE for volumetric, strain, and rotational parameters.

RESULTS

There were no significant differences between 2DSTE and 3DSTE in both control and MS groups for left ventricular volumetric and rotational parameters. 3D global longitudinal strain (GLS) and global circumferential strain (GCS) were significantly higher in healthy volunteers (P < 0.001 for both), while only 3DGCS was significantly higher than 2DGCS in MS group (P < 0.001). The correlation between 3DSTE and 2DSTE was weak-to-moderate in both groups for strain and rotational parameters, and overall, correlation coefficients were higher in MS group. An exception was GLS in MS group, where coefficient of correlation was excellent (r = 0.907). Agreement between two modalities was poor for strain and rotational parameters, and the average bias was high.

CONCLUSIONS

Overall, the agreement between 2DSTE and 3DSTE for strain and rotational measures was poor with a high average bias. The agreement between 2DSTE and 3DSTE is affected by the presence of underlying MS and the direction of strain.

Inter-study reproducibility of left ventricular torsion and torsion rate quantification using MR myocardial feature tracking

BACKGROUND

To determine the inter-study reproducibility of MR feature tracking (MR-FT) derived left ventricular (LV) torsion and torsion rates for a combined assessment of systolic and diastolic myocardial function.

METHODS

Steady-state free precession (SSFP) cine LV short-axis stacks were acquired at 9:00 (Exam A), 9:30 (Exam B), and 14:00 (Exam C) in 16 healthy volunteers at 3 Tesla. SSFP images were analyzed offline using MR-FT to assess rotational displacement in apical and basal slices. Global peak torsion, peak systolic and peak diastolic torsion rates were calculated using different definitions ("twist", "normalized twist" and "circumferential-longitudinal (CL) shear angle"). Exam A and B were compared to assess the inter-study reproducibility. Morning and afternoon scans were compared to address possible diurnal variation.

RESULTS

The different methods showed good inter-study reproducibility for global peak torsion (intraclass correlation coefficient [ICC]: 0.90-0.92; coefficient of variation [CoV]: 19.0-20.3%) and global peak systolic torsion rate (ICC: 0.82-0.84; CoV: 25.9-29.0%). Conversely, global peak diastolic torsion rate showed little inter-study reproducibility (ICC: 0.34-0.47; CoV: 40.8-45.5%). Global peak torsion as determined by the CL shear angle showed the best inter-study reproducibility (ICC: 0.90;CoV: 19.0%). MR-FT results were not measurably affected by diurnal variation between morning and afternoon scans (CL shear angle: 4.8 ± 1.4°, 4.8 ± 1.5°, and 4.1 ± 1.6° for Exam A, B, and C, respectively; P = 0.21).

CONCLUSION

MR-FT based derivation of myocardial peak torsion and peak systolic torsion rate has high inter-study reproducibility as opposed to peak diastolic torsion rate. The CL shear angle was the most reproducible parameter independently of cardiac anatomy and may develop into a robust tool to quantify cardiac rotational mechanics in longitudinal MR-FT patient studies.

Normal left ventricular torsion mechanics in healthy children: age related changes of torsion parameters are closely related to changes in heart rate

Background and Objectives

This study was aimed at assessing left ventricular torsion (LVtor) mechanics using speckle tracking echocardiography (STE), establishing normal reference values of principal LVtor parameters, and analyzing the age-related changes in normal children.

Subjects and Methods

Eighty children (aged 3 months to 15 years) with normal cardiac function and rhythm were recruited. LVtor parameters including rotations, twist and untwist, torsion, and their rate indices were measured using STE. Age and heart rate related changes of the parameters were analyzed.

Results

Speckle tracking echocardiography analyses for LVtor parameters had excellent reliability in 64 of 80 subjects (80%) (intraclass correlation coefficients; 0.93-0.97). Early systolic twist (EST) motions (-8.4--0.1°) were observed in all subjects during an early 20±7% of systolic time intervals. The peak systolic twist and torsion were 17.0±6.5° and 2.9±1.3°/cm, respectively. The peak twist velocity was recorded at 51±13% of systolic time and the peak untwist velocity at 13.8±11.5% of diastolic time intervals. Multivariate analysis showed that heart rate change was an independent predictor of changes in torsion parameters; significantly decreasing LV length-normalized apical and basal rotation, torsion, and twist and untwist rate with increasing age. Isovolumetric recoil rate was independent of change in age and heart rate.

Conclusion

Left ventricle showed unique torsion mechanics in children with EST, torsion, and untwists. Heart rate was an independent predictor of the change in torsion parameters with aging.