scholarly journals Intra-Operative Video-Based Measurement of Biaxial Strains of the Ascending Thoracic Aorta

Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 670
Author(s):  
Shaiv Parikh ◽  
Berta Ganizada ◽  
Gijs Debeij ◽  
Ehsan Natour ◽  
Jos Maessen ◽  
...  

Local biaxial deformation measurements are essential for the in-depth investigation of tissue properties and remodeling of the ascending thoracic aorta, particularly in aneurysm formation. Current clinical imaging modalities pose limitations around the resolution and tracking of anatomical markers. We evaluated a new intra-operative video-based method to assess local biaxial strains of the ascending thoracic aorta. In 30 patients undergoing open-chest surgery, we obtained repeated biaxial strain measurements, at low- and high-pressure conditions. Precision was very acceptable, with coefficients of variation for biaxial strains remaining below 20%. With our four-marker arrangement, we were able to detect significant local differences in the longitudinal strain as well as in circumferential strain. Overall, the magnitude of strains we obtained (range: 0.02–0.05) was in line with previous reports using other modalities. The proposed method enables the assessment of local aortic biaxial strains and may enable new, clinically informed mechanistic studies using biomechanical modeling as well as mechanobiological profiling.

2019 ◽  
Vol 29 (7) ◽  
pp. 954-959 ◽  
Author(s):  
Justin Godown ◽  
William A. McEachern ◽  
Debra A. Dodd ◽  
Michael Stanley ◽  
Corey Havens ◽  
...  

AbstractIntroduction:Myocardial strain measurements are increasingly used to detect complications following heart transplantation. However, the temporal association of these changes with allograft rejection is not well defined. The aim of this study was to describe the evolution of strain measurements prior to the diagnosis of rejection in paediatric heart transplant recipients.Methods:All paediatric heart transplant recipients (2004–2015) with at least one episode of acute rejection were identified. Longitudinal and circumferential strain measurements were assessed at the time of rejection and retrospectively on all echocardiograms until the most recent negative biopsy. Smoothing technique (LOESS) was used to visualise the changes of each variable over time and estimate the time preceding rejection at which alterations are first detectable.Results:A total of 58 rejection episodes were included from 37 unique patients. In the presence of rejection, there were decrements from baseline in global longitudinal strain (−18.2 versus −14.1), global circumferential strain (−24.1 versus −19.6), longitudinal strain rate (−1 versus −0.8), circumferential strain rate (−1.3 versus −1.1), peak longitudinal early diastolic strain rate (1.3 versus 1), and peak circumferential early diastolic strain rate (1.5 versus 1.3) (p<0.01 for all). The earliest detectable changes occurred 45 days prior to rejection with simultaneous alterations in myocardial strain and ejection fraction.Conclusions:Changes in graft function can be detected non-invasively prior to the diagnosis of rejection. However, changes in strain occur concurrently with a decline in ejection fraction. Strain measurements aid in the non-invasive detection of rejection, but may not facilitate earlier diagnosis compared to more traditional measures of ventricular function.


2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
JJ Hjertaas ◽  
E Einarsen ◽  
E Gerdts ◽  
M Kokorina ◽  
CA Moen ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. Background Optimal 3D speckle tracking echocardiography (STE) requires volume stitching, a technique prone to errors, such as patient movements, respiration and arrhythmias. With different resolution at different depths (Figure 1A), such errors may cause stitching artefacts that affect STE derived deformation measurements at different levels of the left ventricle. Methods In this cross-sectional study, 62 patients with variable degree of aortic stenosis participated. 3D images were recorded using 3 different methods (2-, 4- and 6-beat volume stitching at 22 ± 2, 29 ± 4 and 36 ± 6 volumes per second, respectively). Strain, rotation and torsion were analyzed at 3 different levels (basal, mid and apical) (Figure 1B). Results were compared using one-way analysis of variance between methods. Inter-segmental variation was estimated using the coefficient of variation (CV) of the segments involved for each level. Results were interpreted as more accurate if low values of inter-segmental variation between segments in a level was present. Results Neither longitudinal strain (LS) nor circumferential strain (CS) showed any difference between methods in the basal level (Table 1). LS was higher in mid and apical level for 2-beat, while CS was higher only in apical level for 2-beat. Inter-segmental CV showed no significant difference between methods for LS and CS. Between levels, both had higher CV in basal than apical level, but CS had much higher values, indicating lower accuracy in basal level. Rotation measurements showed negative values in basal level and positive in apical level. None of the methods differed significantly. Torsion showed higher values for 2 beat images only. Conclusion 3D STE from both 4- and 6 beat images have insignificant differences for strain, as well as low inter-segmental variability. LS is accurate in all levels while CS has high accuracy in apical, and poor in basal level. Both rotation and torsion differ insignificantly when using 4- and 6-beat images. Table 1 Level Mean ± SD ANOVA P CV 2-beat 4-beat 6-beat 2-beat 4-beat 6-beat Longitudinal strain (%) Basal -17.82 ± 4.83 -16.81 ± 4.48 -17.05 ± 3.56 0.402 34.5 34.9 31.5 Mid -16.34 ± 4.30 -14.91 ± 3.62 -14.46 ± 3.53 0.019 31.4 29.9 29.9 Apical -16.80 ± 4.33 -15.06 ± 3.12 -15.09 ± 3.02 0.008 30.6 28.5 24.9 Circumferential strain (%) Basal -12.93 ± 4.42 -14.16 ± 4.21 -13.05 ± 3.24 0.168 106.7 71.7 74.4 Mid -17.59 ± 3.86 -16.73 ± 3.56 -16.98 ± 3.51 0.406 43.0 36.9 30.3 Apical -22.14 ± 6.20 -19.04 ± 4.81 -20.32 ± 5.40 0.008 26.8 29.4 23.4 Abstract Figure 1


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S Anwer ◽  
P.S Heiniger ◽  
S Rogler ◽  
D Cassani ◽  
L Rebellius ◽  
...  

Abstract Introduction Echocardiography-based deformation analysis is used for studying left ventricular (LV) mechanics and have an emerging role in the diagnosis of cardiomyopathies. Left ventricular non-compaction (LVNC) is a rare cardiomyopathy characterised by a two-layered LV myocardium with prominent trabeculae separated by deep recesses perfused from the LV cavity. Left ventricular hypertrabeculation (LVHT) may be difficult to differentiate from LVNC. In this study, we aim to develop a diagnostic algorithm based on the circumferential deformation (CD) of LVNC, LVHT and controls; and find their associations with LVNC outcomes. Methods We compared 45 LVNC patients, 45 LVHT individuals, and 45 matched healthy controls. LVNC was diagnosed according to current echocardiographic criteria. LVHT was defined as presence of three or more trabeculae in the LV apex visualised in both parasternal short axis and apical views. Controls had a normal echocardiographic examination and no evidence of cardiovascular disease. Strain analysis was performed using TomTec Image-Arena (version 4.6). Results Receiver observer characteristics curve (ROC) analyses revealed that GCS &lt;22.3% differentiated LVNC from control or LVHT. In individuals with global circumferential strain (GCS) below 22.3%, an apical peak circumferential strain (PCS) cut-off value of 18.4% differentiated LVNC [&lt;18.4%] and LVHT [≥18.4%] (fig. 1). An independent echocardiographer (Table 1) performed blind validation of diagnosis on 32 subjects from each group. Combined endpoint of cardiovascular events in LVNC (CVE) is described in figure 2. Multi-variate regression analyses have shown that GCS was associated with 11-fold increased risk of CVE independent of LVEF and NC:C ratio, while global longitudinal strain (GLS) displayed only 2-fold increased risk. Regional basal and apical peak circumferential or longitudinal strain, left ventricular twist, basal-apical rotation ratio have shown significant associations (Fig. 3). Conclusions A diagnostic algorithm with GCS and aPCS (threshold value 18.4%) differentiates LVNC from LVHT and control with very high sensitivity and specificity independent of additional echocardiographic or clinical information. Circumferential strain derived parameters exhibit a very strong association with outcomes independent of LVEF and NC:C ratio. Absence of CVE in LVHT provides further evidence on the distinct nature of LVNC and LVHT. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): 2018 research grant from the Swiss Heart Foundation


2018 ◽  
Vol 74 (3) ◽  
pp. 188-197 ◽  
Author(s):  
Oana Mirea ◽  
Oana Maria Corîci ◽  
Mihaela Berceanu ◽  
Ionuţ Donoiu ◽  
Constantin Militaru ◽  
...  

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Barbara Cifra ◽  
Andreea Dragulescu ◽  
Heynric Grotenhuis ◽  
Cedric Manlhiot ◽  
Mark K Friedberg ◽  
...  

Introduction: Arterial switch operation (ASO) is the standard surgical procedure for transposition of the great arteries allowing a complete anatomical and physiological repair. In these patients the functional impact of myocardial perfusion on global and regional myocardial function has not been investigated. Stress echocardiography with visual myocardial assessment has been used to detect regional myocardial dysfunction. Studying LV mechanics using speckle-tracking echocardiography during exercise could provide more quantitative information. The aim of the study was to study the myocardial response to exercise in children after ASO using semi-supine cycle ergometry stress echocardiography (SSCE). Materials and Methods: Forty children after ASO and 29 age and gender matched controls were included. Median age was 14 years. A stepwise SSCE protocol was used. LV global longitudinal strain and circumferential strain was measured in all subjects at rest and at incremental heart rate. Results: Resting HR was similar between groups, peak HR was lower in the ASO group compared with controls (142 ±11 vs 157±14 bpm, p=0.0007). LV global longitudinal strain was lower at rest (19±2.3% vs. 21±2.5%, p=0.004) but not at peak exercise (22.7±5.6 % vs. 24±4.5 % p=0.2) in the ASO group compared to controls. No significant difference was found in LV global circumferential strain at rest (23.7±2.3% vs. 24±3.2 %, p=0.6) and peak exercise (28±2.6% vs. 27.9±4.1 %, p=0.9). Also when plotted versus heart rates the increase in longitudinal and circumferential strain values were not significantly different. Conclusions: These data show that circumferential and longitudinal myocardial deformation during exercise is preserved in children after ASO compared to controls. Earlier data obtained using Tissue Doppler in the same study cohort, showed a normal increase in systolic tissue Doppler velocities. These data suggest a preserved LV reserve during exercise in this patient cohort.


Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Aparna Kulkarni ◽  
Jose Miguel Mateo D Lorenzo ◽  
Talin Gulesserian ◽  
Frederick Kaskel ◽  
Joseph Mahgerefteh

Background: Obesity (OB) and hypertension (HTN) are risk factors for early cardiovascular disease (CVD). The aim of this study was to determine the effect of OB and HTN on myocardial mechanics in children using speckle-tracking echocardiography (STE). Methods: Echocardiograms (echo) and ambulatory blood pressure monitors were performed in children referred for HTN from 2009 to 2014. Traditional echo Doppler indices, mass and volume parameters, 24-hr systolic blood pressures (24SBP) and 24-hr diastolic BP indices were obtained. Post-processing was performed on the 2D gray scale images of LV in apical 4-chamber and parasternal short axis mid-papillary views to obtain strain indices (Image Arena, Tomtec). Associations of obesity and BP to the myocardial indices were explored independently using Spearman correlation coefficient. Results: Among 107 patients, 6 - 21 yrs age, 79.4% were males; 42% OB and 53% were hypertensive. Mean Z scores for BMI were 1.5 ± 1.1 and SBP were 1.5 ± 1.2. Mean LV mass (LVM, 2D area-length) was 131 + 42.8 gms, LVMI 2.7 was 40.7 + 9.6 gms, LVM/volume ratio was 0.94 + 0.17. Mean mitral septal E/e’ was 8.3 + 2.1, lateral E/e’ was 5.9 + 1.5 and mitral E/A ratio was 1.8 + 0.4. The mean global longitudinal strain (GLS) was – 17.7 + 3.6, global circumferential strain (GCS) was -20.4 + 3.8, average radial strain (ARS) was 22 + 11.9, average longitudinal strain rate (ALSR) was -1.0 + 0.35 and average circumferential strain rate (ACSR) was -1.5 + 0.5 for all patients. BMI Z scores positively correlated with LVM (r=0.38, p<0.01), LVM/vol (r=0.32, p<0.01), mitral E/e’ (r=0.28, p<0.01), LVMI 2.7 (r=0.5, <0.01). Increased BMI negatively correlated to GLS, GCS and ACSR (r=0.3, p<0.01). Higher SBP, diastolic and mean BP were associated with higher mitral medial E/e’ (r=0.3, p<0.01), however did not have statistically significant correlations to strain indices. Conclusions: Obesity causes adverse cardiac remodeling in obese children. This may provide insights into mechanisms of long-term CV effects of obesity. Myocardial effects of HTN were not apparent, possibly due to heterogeneity of the study group and low power.


2019 ◽  
Vol 29 (3) ◽  
pp. 325-337
Author(s):  
Laurens P. Koopman ◽  
Bas Rebel ◽  
Devi Gnanam ◽  
Mirthe E. Menting ◽  
Willem A. Helbing ◽  
...  

AbstractBackgroundMyocardial deformation by speckle tracking echocardiography provides additional information on left ventricular function. Values of myocardial deformation (strain and strain rate) depend on the type of ultrasound machine and software that is used. Normative values for QLAB (Philips) are scarce, especially for children. It is important to evaluate the influence of age and body size on myocardial deformation parameters, since anthropometrics strongly influence many standard echocardiographic parameters. The aim of this study was to provide comprehensive normal values for myocardial deformation of the left ventricle using a Philips platform and to evaluate the association with anthropometric and standard echocardiographic parameters.MethodsHealthy children between 1 and 18 years of age were prospectively examined using a standard echocardiographic protocol. Short-axis and apical four-chamber, two-chamber, and three-chamber views were used to measure peak systolic circumferential and longitudinal strain and systolic and early diastolic strain rate of the left ventricle using dedicated software.ResultsA total of 103 children were included with a mean age of 10.8 and inter-quartile range 7.3–14.3 years. Global circumferential strain values (±SD) were −24.2±3.5% at basal, −25.8±3.5% at papillary muscle, and −31.9±6.2% at apex levels. Global left ventricular longitudinal strain values were −20.6±2.6% in apical four-chamber view, −20.9±2.7% in apical two-chamber, and −21.0 ±2.7% in apical three-chamber. Age was associated with longitudinal strain, longitudinal systolic and early diastolic strain rate, but not with circumferential strain.ConclusionsNormal values for left ventricular deformation parameters in children are obtained using a Philips platform. Age partly explains normal variation of strain and strain rate.


2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
F Jarjour ◽  
S Civera ◽  
A Vijiiac ◽  
B Elnagar ◽  
C Palermo ◽  
...  

Abstract Background Left atrium (LA) is a dynamic structure which is functionally coupled with the left ventricle and modulates its function in many cardiac conditions. The geometric and functional remodeling of the LA occurring early after myocardial infarction are poorly understood. Purpose We sought to evaluate the early changes in LA geometry and function occurring in survivors of a first acute ST-elevation myocardial infarction (STEMI), using three-dimensional echocardiography (3DE). Methods LA phasic volumes and strain (both longitudinal and circumferential) were measured using a dedicated automated software package in 54 patients at pre-discharge after STEMI, and in 54 age- and sex-matched healthy volunteers (controls), (figure 1). Results In STEMI patients, both maximal (LAV max) and minimal (LAV min) LA volumes were significantly larger than in controls 63 ± 15 vs. 53 ±11 ml; p = 0,002 and 38 ± 15 ml vs. 25 ± 6; p &lt;0.0001 (respectively). Moreover, when compared to controls (Table 1). Both longitudinal (LASr) and circumferential strain reservoirs showed a significant negative correlation with peak cardiac troponin I values (r=-0.344; p = 0.007 and r=-0.357; p = 0.005, respectively) as an estimate of the extent of myocardial damage. Conclusion STEMI was associated to significant geometrical and functional remodeling of the LA which was correlated with the extent of myocardial damage. Table 1 Controls STEMI patients P-value Longitudinal% LASr 21.8 ± 8.4 13.72 ± 8.27 &lt;0.0001 LAScd -12.8 ± 8.48 -6.43 ± 4.74 &lt;0.0001 LASct -9.73 ± 6.04 -7.26 ± 5.87 0.05 Circumferential % LASr-c 27.31 ± 8.07 18.92 ± 9.16 &lt;0.0001 LAScd-c -11.2 ± 5.93 -6.46 ± 5.68 0.0002 LASct-c -16.22 ± 6.33 -12.41 ± 5.94 0.004 LASr longitudinal strain reservoir, LAScd: longitudinal strain conduit, LAScd: longitudinal strain contraction, LASr-c: circumferential strain reservoir, LAScd-c: circumferential strain conduit , LASct-c:circumferential strain contraction Abstract P669 Figure 1


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
A Guala ◽  
G Teixido Tura ◽  
J F Rodriguez-Palomares ◽  
A Ruiz Munoz ◽  
C Granato ◽  
...  

Abstract Background The most common cardiovascular complications in Marfan syndrome (MFS) are aortic root dilation and type A aortic dissections. Elective aortic root surgery is indicated when maximum aortic diameter is larger than a defined threshold or in the case of fast-progressing dilation. However, maximum aortic diameter is limited for the prediction of aortic events. Indeed, a large international registry of acute aortic syndromes reported that as much as 40% of aortic dissections happen with maximum aortic diameter lower than 50 mm. Consequently, there is a need for new, non-invasive biomarkers to improve the prediction of aortic complications. Purpose The aim of the present study was to assess if proximal aorta circumferential and longitudinal strain and ascending aorta distensibility were associated with progressive aortic dilation and incidence of aortic events in Marfan syndrome patients. Methods Eighty seven Marfan syndrome patients free from previous cardiac/aortic surgery or dissection, were prospectively included in a multicenter follow-up. Patients were diagnosed by original Ghent criteria. Proximal aorta longitudinal and circumferential strain and distensibility were computed from baseline cine CMR images by means of feature-tracking. The predictive capacity of each stiffness biomarkers was separately tested with multivariable linear regression analysis (aortic growth) and with Cox logistic regression analysis (aortic events), both corrected for clinical and demographic variables, including baseline maximum aortic diameter. Results During a follow-up of 81.6±17 months, mean diameter growth-rate was 0.65±0.67 mm/year and z-score growth rate was 0.07±0.13 / year. Elective aortic root replacement was performed in 11 patients while two patients presented type A aortic dissection.Baseline proximal aorta longitudinal strain was independently related to diameter growth-rate (p=0.001), z-score growth-rate (p=0.018) and aortic events (p=0.018). Conversely, neither circumferential strain nor distensibility were independent predictors of diameter growth-rate (p=0.385 and p=0.381, respectively), z-score growth-rate (p=0.515 and p=0.484, respectively) and aortic events (p=0.064 and p=0.205, respectively). Conclusions Proximal aorta longitudinal strain predicts aortic root dilation and major aortic events in Marfan syndrome patients beyond aortic root diameter and clinical and demographic characteristics. Acknowledgement/Funding ISCIII PI14/0106, La Maratό de TV3 (20151330) and CIBERCV. Guala A. FP7/People n° 267128


1991 ◽  
Vol 113 (3) ◽  
pp. 350-353 ◽  
Author(s):  
K. C. Wang ◽  
W. N. Sharpe

A preceding paper reported the results of biaxial strain measurements at the roots of notched aluminum specimen subjected to monotonic tension loading. The specimens had different amounts of constraints at the notch root, and it was shown that a modified version of the Neuber relation gave some improvement in its predictive capability. Several of those specimens were also subjected to fully reversed cyclic loading until microcracks formed at the notch roots, and the results of those biaxial strain measurements are reported here. The modified Neuber relation in the cyclic form was used to predict the strains at the notch roots. Reasonably close agreement between the predicted and the measured load-strain loops was found for all three levels of constraint.


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