3D Strain helps relating LV function to LV and structure in athletes

Normative healthy reference values for global and segmental 3D principal and geometry dependent strain from cine cardiac magnetic resonance imaging

3-Dimensional (3D) myocardial deformation analysis (3D-MDA) enables novel descriptions of geometry-independent principal strain (PS). Applied to routine 2D cine cardiovascular magnetic resonance (CMR), this provides unique measures of myocardial biomechanics for disease diagnosis and prognostication. However, healthy reference values remain undefined. This study describes age- and sex-stratified reference values from CMR-based 3D-MDA, including 3D PS. One hundred healthy volunteers were prospectively recruited following institutional ethics approval and underwent CMR imaging. 3D-MDA was performed using validated software. Age- and sex-stratified global and segmental strain measures were derived for conventional geometry-dependent [circumferential (CS), longitudinal (LS), and radial (RS)] and geometry-independent [minimum (minPS) and maximum principal (maxPS)] directions of deformation. Layer-specific contraction angle interactions were determined using local minPS vectors. The average age was 43 ± 15 years and 55% were women. Strain measures were higher in women versus men. 3D PS-based assessment of maximum tissue shortening (minPS) and maximum tissue thickening (maxPS) were greater than corresponding geometry-dependent markers of LS and RS, consistent with improved representation of local tissue deformations. Global maxPS amplitude best discriminated both age and sex. Segmental analyses showed greater strain amplitudes in apical segments. Transmural PS contraction angles were higher in females and showed a heterogeneous distribution across segments. In this study we provided age and sex-based reference values for 3D strain from CMR imaging, demonstrating improved capacity for 3D PS to document maximal local tissue deformations and to discriminate age and sex phenotypes. Novel markers of layer-specific strain angles from 3D PS were also described.

Myocardial Fitness of Bicuspid Aortic Valve Athletes during COVID 19 Pandemic

COVID 19 pandemic has induced a large sedentarism in several kinds of sports. Some peculiar categories of athletes could particularly suffer from a prolonged inactivity as those affected by minimal cardiopathies as bicuspid aortic valve (BAV) athletes. This study aims to verify the myocardial performance in a restricted group of BAV athletes compared to a control group of agonistic athletes evaluated by traditional echocardiography and deformation parameters. 2D standard and deformations parameters were measured at rest conditions in BAV athletes and controls. Particularly EF, LVDD/LVS diameters, GLS rotation and twisting were considered as myocardial performance data; E/A, E1 and A1 as diastolic ones. All the 2D standard parameters measured were within the normal range in both groups, especially the EF value. Significant differences were found in the diastolic function with reduced values of E and E1 waves in BAV vs. controls. The strain analysis showed a significant reduction in GLS measured in 2C, 3C, 4C in BAV if compared to controls, while no significant differences were found in torsional and rotational parameters. These results are suggestive for a potential long term negative impact of inactivity on cardiac performance more evident in BAV athletes, if compared to athletes with normal aortic valve. GLS of LV and RV can be considered as a predictive parameter of this mild dysfunction and assumed as follow-up parameter to restore a progressive training.

Morning blood pressure surge in the early stage of hypertensive patients impacts three-dimensional left ventricular speckle tracking echocardiography

BACKGROUND

The aim of this study was to examine left ventricular (LV) function in untreated, newly diagnosed hypertensive patients with morning blood pressure surge (MBPS) status using three-dimensional (3D) speckle tracking echocardiography (STE).

METHODS

In this study, 163 newly diagnosed hypertensive patients were included, and all patients underwent 24-h ambulatory blood pressure monitoring (ABPM). According to ABPM, participants were divided into a MBPS group and a non-MBPS group. The entire study population was examined by complete two-dimensional (2D) transthoracic echocardiography (TTE) and 3D STE.

RESULT

The results of this study showed that 3D LV longitudinal strain was significantly decreased in the MBPS group compared with the non-MBPS group (- 30.1 ± 2.0 vs. -31.1 ± 2.7, p = 0.045). Similar trends were observed for 3D twist (9.6 ± 6.1 vs. 12.1 ± 4.8, p = 0.011) as well as for 3D torsion (1.23 ± 0.78 vs. 1.49 ± 0.62, p = 0.042). The LV principal strain was decreased in the MBPS group (- 33.9 ± 1.7 vs. -35.5 ± 2.8, p < 0.001). The 3D LV global longitudinal strain (GLS) and principal strain were significantly associated with quartile of MBPS as measured by systolic blood pressure (SBP).

CONCLUSION

The 3D STE revealed that LV mechanics were more impaired in the MBPS group than in the non-surge newly diagnosed, untreated hypertensive patients; even the 2D TTE parameters showed no difference.

Bicuspid aortic valve and sports: From the echocardiographic evaluation to the eligibility for sports competition

Bicuspid aortic valve (BAV) is the most common congenital heart defect in adults. Although a BAV may remain without clinical consequences for a lifetime, it can deteriorate in aortic valve stenosis and regurgitation and aortic dilatation. Unfortunately, the impact of regular training on patients with BAV and its natural course is not fully understood, although preliminary evidence suggests that the progression of valvular disease occurs primarily in an independent manner from sports practice. The current review aims to report how to perform a comprehensive echocardiographic examination in athletes with BAV and analyze the current literature on the influence of sports practice and how it impacts the aortic valve in athletes with BAV. The article also summarizes the current recommendations on sports eligibility and disqualification for competitive athletes with BAV.

Dissecting myocardial mechanics in patients with severe aortic stenosis: 2-dimensional vs 3-dimensional-speckle tracking echocardiography

Background

Aortic stenosis (AS) causes left ventricular (LV) pressure overload, leading to adverse LV remodeling and dysfunction. Identifying early subclinical markers of LV dysfunction in patients with significant AS is critical as this could provide support for earlier intervention, which may result in improved long-term outcomes. We therefore examined the impact of severe AS and its consequent increase in LV afterload on myocardial deformation and rotational mechanics by 2-dimensional (2D) and 3-dimensional (3D) speckle-tracking echocardiography.

Methods

We prospectively measured various strain parameters in 168 patients (42% female, mean age 72 ± 12 years) with severe AS and LV ejection fraction (EF) ≥50%, and compared them to normal values found in literature. 2D and 3D images were analyzed for global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), basal rotation, apical rotation, and peak systolic twist. We further assessed the degree of concordance between 2D and 3D strain, and examined their association with measures of LV preload and afterload.

Results

Patients with severe AS exhibited significantly lower GLS and GRS but higher GCS, apical rotation, and twist by 2D and 3D echocardiography compared with published normal values (P = 0.003 for 3D twist, P < 0.001 for all others). Agreement between 2D- and 3D-GLS by concordance correlation coefficient was 0.49 (95% confidence interval: 0.39–0.57). GLS was correlated with valvulo-arterial impedance, a measure of LV afterload (r = 0.34, p < 0.001 and r = 0.23, p = 0.003, respectively).

Conclusion

Patients with severe AS demonstrated lower-than-normal GLS and GRS but appear to compensate with higher-than-normal GCS, apical rotation, and twist in order to maintain a preserved LVEF. GLS showed a modest correlation with valvulo-arterial impedance.

The value of left ventricular strain-volume loops in predicting response to cardiac resynchronization therapy

BACKGROUND

Three-dimensional (3D) speckle tracking imaging (STI) allows the simultaneous assessment of left ventricular (LV) strain and volume. We aim to explore the value of LV strain-volume loops in predicting response to cardiac resynchronization therapy (CRT).

METHODS

Forty heart failure (HF) patients scheduled for CRT and twenty healthy individuals were enrolled. All subjects received a 3D echocardiography and 3D STI analysis to acquire LV global and segmental principal strain (PS) and volume simultaneously. Values were plotted in a Cartesian system to construct PS-volume loop which was assessed using the two characteristics of the linear fitting curve: the slope and the coefficient of determination (R²-S/D coupling).

RESULTS

HF patients at baseline showed significantly lower slope and R²-S/D coupling of all PS-volume loops than healthy subjects. As for as comparing Segmental PS-Global volume loop at baseline, Midseptal R²-S/D coupling was lower and Midlateral slope was higher in CRT responders than in non-responders. For each individual, the abnormal segmental heterogeneity of Midseptal slope and R²-S/D coupling were lower than Midlateral was observed only in responders. At follow-up, significant improvements of the Midseptal slope and R²-S/D coupling were observed in responders. Midseptal R²-S/D coupling at baseline was an independent predictor of CRT response and the cut-off value of 0.55 was recommended with sensitivity of 89% and specificity of 77%.

CONCLUSIONS

Analysis of strain-volume loops could provide unique information for predicting response to CRT. Assessment of septal myocardial wasted work at baseline is helpful to improve patient selection for CRT.

Strain measurement on four-dimensional dynamic-ventilation CT: quantitative analysis of abnormal respiratory deformation of the lung in COPD

Purpose

Strain measurement is frequently used to assess myocardial motion in cardiac imaging. This study aimed to apply strain measurement to pulmonary motion observed by four-dimensional dynamic-ventilation computed tomography (CT) and to clarify motion abnormality in COPD.

Materials and methods

Thirty-two smokers, including ten with COPD, underwent dynamic-ventilation CT during spontaneous breathing. CT data were continuously reconstructed every 0.5 seconds. In the series of images obtained by dynamic-ventilation CT, five expiratory frames were identified starting from the peak inspiratory frame (first expiratory frame) and ending with the fifth expiratory frame. Strain measurement of the scanned lung was performed using research software that was originally developed for cardiac strain measurement and modified for assessing deformation of the lung. The measured strain values were divided by the change in mean lung density to adjust for the degree of expiration. Spearman’s rank correlation analysis was used to evaluate associations between the adjusted strain measurements and various spirometric values.

Results

The adjusted strain measurement was negatively correlated with FEV₁/FVC (ρ=−0.52, P<0.01), maximum mid-expiratory flow (ρ=−0.59, P<0.001), and peak expiratory flow (ρ=−0.48, P<0.01), suggesting that abnormal deformation of lung motion is related to various patterns of expiratory airflow limitation.

Conclusion

Abnormal deformation of lung motion exists in COPD patients and can be quantitatively assessed by strain measurement using dynamic-ventilation CT. This technique can be expanded to dynamic-ventilation CT in patients with various lung and airway diseases that cause abnormal pulmonary motion.

The impact of preload on 3-dimensional deformation parameters: principal strain, twist and torsion

Background

Strain analysis is feasible using three-dimensional (3D) echocardiography. This approach provides various parameters based on speckle tracking analysis from one full-volume image of the left ventricle; however, evidence for its volume independence is still lacking.

Methods

Fifty-eight subjects who were examined by transthoracic echocardiography immediately before and after hemodialysis (HD) were enrolled. Real-time full-volume 3D echocardiographic images were acquired and analyzed using dedicated software. Two-dimensional (2D) longitudinal strain (LS) was also measured for comparison with 3D strain values.

Results

Longitudinal (pre-HD: −24.57 ± 2.51, post-HD: −21.42 ± 2.15, P < 0.001); circumferential (pre-HD: −33.35 ± 3.50, post-HD: −30.90 ± 3.22, P < 0.001); and radial strain (pre-HD: 46.47 ± 4.27, post-HD: 42.90 ± 3.61, P < 0.001) values were significantly decreased after HD. The values of 3D principal strain (PS), a unique parameter of 3D images, were affected by acute preload changes (pre-HD: −38.10 ± 3.71, post-HD: −35.33 ± 3.22, P < 0.001). Twist and torsion values were decreased after HD (pre-HD: 17.69 ± 7.80, post-HD: 13.34 ± 6.92, P < 0.001; and pre-HD: 2.04 ± 0.86, post-HD:1.59 ± 0.80, respectively, P < 0.001). The 2D LS values correlated with the 3D LS and PS values.

Conclusion

Various parameters representing left ventricular mechanics were easily acquired from 3D echocardiographic images; however, like conventional parameters, they were affected by acute preload changes. Therefore, strain values from 3D echocardiography should be interpreted with caution while considering the preload conditions of the patients.

Strain Imaging Echocardiography: What Imaging Cardiologists Should Know

Despite recent advances in clinical imaging, echocardiography remains as the most accessi-ble and reliable noninvasive. Since knowledge of left ventricular systolic function remains so critically important in determining prognosis; every effort should be made to prevent subjective estimations. The advent of strain imaging echocardiography now offers a readily available and portable imaging tool that not only offers an objective characterization of myocardial dynamics; but also allows for early detection of subclinical left ventricular dysfunction. This review outlines the basic concepts of strain imaging to better understand the mechanism of myocardial function as well their applicability in the least common cardiac diagnosis among current clinical practice.

Comparison of left ventricular mechanics in runners versus bodybuilders using speckle tracking echocardiography

Background

Athlete’s heart is a common definition for a broad spectrum of adaptations induced by intense exercise. We intended to compare left ventricular (LV) mechanics in two sports disciplines with different exercise nature: marathon runners (endurance) and bodybuilders (power).

Methods

24 marathon or ultramarathon runners (R), 14 bodybuilders (B) and 15 healthy, sedentary male volunteers (N) were investigated. Beyond standard echocardiographic protocol, parasternal short-axis and apical recordings optimized for speckle tracking analysis were acquired (Esaote MyLab 25). Using dedicated software (TomTec 2D Performance Analysis), global longitudinal (GLS), circumferential (GCS) and radial strain (GRS) were calculated by averaging the corresponding 16 LV segments. Data are presented as mean ± SD.

Results

Calculated LV mass was higher in bodybuilders compared to normal controls (R vs. B vs. N: 198 ± 52 vs. 224 ± 69 vs. 186 ± 30 g, p < 0.05). We found no difference regarding conventional systolic function parameters among the groups (ejection fraction: 55 ± 9 vs. 60 ± 6 vs. 59 ± 5%; mitral lateral S’ velocity: 10.7 ± 0.6 vs. 10.6 ± 0.4 vs. 11.0 ± 0.8 cm/s). However, speckle tracking analysis showed a different pattern of myocardial deformation in our groups: while GRS was similar, GLS was decreased in runners, GCS was decreased in bodybuilders compared to the other two groups (GLS: -19.4 ± 3.4 vs. -23.3 ± 2.1 vs. -24.1 ± 3.0; GCS: -26.6 ± 3.8 vs. -22.4 ± 4.3 vs. -26.4 ± 2.7%, p < 0.05). Significant correlations were found in runners between GLS and end-diastolic volume (r = 0.46; p < 0.05), and body surface area (r = 0.49; p < 0.05). In bodybuilders, GCS was closely related to LV mass (r = 0.61; p < 0.01) and systolic blood pressure (r = 0.42; p < 0.05).

Conclusions

While conventional morphological and functional echocardiographic parameters failed to distinguish between the athlete’s heart of the two different sport disciplines, deformation parameters showed a different pattern of LV mechanics in runners versus bodybuilders.

Electronic supplementary material

The online version of this article (doi:10.1186/s12947-015-0002-y) contains supplementary material, which is available to authorized users.