Article

PDF
Access to the PDF text
Advertising


Free Article !

Archives of cardiovascular diseases
Volume 109, n° 10
pages 533-541 (octobre 2016)
Doi : 10.1016/j.acvd.2016.02.007
Received : 4 September 2015 ;  accepted : 5 February 2016
Could quantitative longitudinal peak systolic strain help in the detection of left ventricular wall motion abnormalities in our daily echocardiographic practice?
Le pic du strain systolique longitudinal segmentaire peut-il aider dans l’analyse des anomalies de cinétique segmentaire du ventricule gauche en routine échocardiographique ?
 

Nadia Benyounes a, , Sylvie Lang b, Olivier Gout c, Yann Ancédy b, Arnaud Etienney b, Ariel Cohen b
a Fondation Ophtalmologique A.-de-Rothschild, Cardiology Unit, Paris, France 
b Saint-Antoine Hospital, Department of Cardiology, Paris, France 
c Fondation Ophtalmologique A.-de-Rothschild, Department of Neurology, Paris, France 

Corresponding author. Fondation Ophtalmologique A.-de-Rothschild, Cardiology Unit, 25, rue Manin, Paris 19, France.
Summary
Background

Transthoracic echocardiography is the most commonly used tool for the detection of left ventricular wall motion (LVWM) abnormalities using “naked eye evaluation”. This subjective and operator-dependent technique requires a high level of clinical training and experience. Two-dimensional speckle-tracking echocardiography (2D-STE), which is less operator-dependent, has been proposed for this purpose. However, the role of on-line segmental longitudinal peak systolic strain (LPSS) values in the prediction of LVWM has not been fully evaluated.

Aim

To test segmental LPSS for predicting LVWM abnormalities in routine echocardiography laboratory practice.

Methods

LVWM was evaluated by an experienced cardiologist, during routine practice, in 620 patients; segmental LPSS values were then calculated.

Results

In this work, reflecting real life, 99.6% of segments were successfully tracked. Mean (95% confidence interval [CI]) segmental LPSS values for normal basal (n =3409), mid (n =3468) and apical (n =3466) segments were –16.7% (–16.9% to –16.5%), –18.2% (–18.3% to –18.0%) and –21.1% (–21.3% to –20.9%), respectively. Mean (95% CI) segmental LPSS values for hypokinetic basal (n =114), mid (n =116) and apical (n =90) segments were –7.7% (–9.0% to –6.3%), –10.1% (–11.1% to –9.0%) and –9.3% (–10.5% to –8.1%), respectively. Mean (95% CI) segmental LPSS values for akinetic basal (n =128), mid (n =95) and apical (n =91) segments were –6.6% (–8.0% to –5.1%), –6.1% (–7.7% to –4.6%) and –4.2% (–5.4% to –3.0%), respectively. LPSS allowed the differentiation between normal and abnormal segments at basal, mid and apical levels. An LPSS value–12% detected abnormal segmental motion with a sensitivity of 78% for basal, 70% for mid and 82% for apical segments.

Conclusions

Segmental LPSS values may help to differentiate between normal and abnormal left ventricular segments.

The full text of this article is available in PDF format.
Résumé
Contexte

L’évaluation visuelle en échocardiographie transthoracique est l’outil le plus couramment utilisé pour analyser les anomalies de la cinétique segmentaire du ventricule gauche. Cette technique subjective requiert un opérateur expérimenté. L’imagerie de Speckle bidimensionnelle semble moins dépendante de l’opérateur et a été proposée à cet effet. Cependant, le rôle des valeurs des pics systoliques du strain longitudinal (LPSS) segmentaire obtenues en direct pendant l’examen échographique pour la prédiction des anomalies de cinétique segmentaire n’a pas été pleinement évalué.

Objectif

L’objectif de cette étude était de tester la capacité des valeurs de LPSS segmentaire à prédire les anomalies de cinétique segmentaire, dans un contexte de pratique échocardiographique de routine.

Méthodes

La cinétique segmentaire du ventricule gauche a été évaluée par un cardiologue expérimenté, chez 620 patients consécutifs. Les valeurs des LPSS segmentaires ont ensuite été calculées durant le même examen.

Résultats

Au total, 99,6 % des segments ont été traqués avec succès. Les valeurs moyennes (IC 95 %) du LPSS pour les segments basaux normaux (n =3409), moyens normaux (n =3468) et apicaux normaux (n =3466) étaient : –16,7 % (–16,9 % à –16,5 %), –18,2 % (–18,3 % à –18,0 %) et –21,1 % (–21,3 % à –20,9 %), respectivement. Les valeurs moyennes (IC 95 %) du LPSS pour les segments basaux hypokinétiques (n =114), moyens hypokinétiques (n =116) et apicaux hypokinétiques (n =90) étaient : –7,7 % (–9,0 % à –6,3 %), –10,1 % (–11,1 % à –9,0 %) et –9,3 % (–10,5 % à –8,1 %), respectivement. Les valeurs moyennes (IC 95 %) du LPSS pour les segments basaux akinétiques (n =128), moyens akinétiques (n =95) et apicaux akinétiques (n =91) étaient : –6,6 % (–8,0 % à –5,1 %), –6,1 % (–7,7 % à –4,6 %) et –4,2 % (–5,4 % à –3,0 %), respectivement. Les valeurs segmentaires du LPSS ont permis la différenciation entre les segments normaux et anormaux aux trois étages (basal, moyen et apical). Une valeur de LPSS–12 % détecte une cinétique segmentaire anormale avec une sensibilité de 78 % au niveau basal, 70 % au niveau moyen et 82 % au niveau apical.

Conclusion

Les valeurs segmentaires du LPSS peuvent aider à différencier les segments anormaux des segments normaux du ventricule gauche.

The full text of this article is available in PDF format.

Keywords : 2D strain, Segmental longitudinal peak systolic strain, Left ventricular wall motion, Naked eye evaluation

Mots clés : Strain-2D, Imagerie de speckle, Pic de déformation systolique du strain segmentaire, Cinétique segmentaire du VG, Fonction régionale du VG

Abbreviations : 2D, 2D-STE, AUC, CI, GLS, LPSS, LV, LVEF, LVWM, ROC, TTE


Background

Echocardiography is the main, but not the only tool for the evaluation of left ventricular wall motion (LVWM). The analysis is usually based on visual “naked eye” evaluation. The interpretation of LVWM abnormalities is an important component of transthoracic echocardiography (TTE), but is prone to intra- and interobserver variability [1], especially when the acoustic window is suboptimal and the echographer less experienced.

New echocardiographic techniques are now available for the assessment of left ventricular (LV) systolic function, one of which is two-dimensional speckle-tracking echocardiography (2D-STE). This technique allows the study of global myocardial deformation by an index called global longitudinal strain (GLS) [2], and segmental myocardial deformation by the measurement of segmental longitudinal peak systolic strain (LPSS) values. Deformation variables are thought to be more reproducible, and can now be obtained on-line during the ultrasound examination, therefore requiring no off-line analysis [3].

This study aimed to determine the usefulness of segmental LPSS values for predicting LVWM abnormalities during routine in-hospital echocardiographic activity on consecutive patients, regardless of the indication for TTE. The study is based on the hypothesis that a method that requires only limited user interaction would help to improve the robustness of echocardiographic assessments of LVWM abnormalities in routine clinical practice, as has been demonstrated to be the case for LV ejection fraction (LVEF) [4].

Methods
Study population

A total of 620 consecutive patients undergoing TTE assessment in our echocardiography laboratory by the same echocardiographer (N.B.) between August 2012 and March 2014 entered the analysis. The echocardiographer had 12 years of experience, carrying out 700 TTE scans per year. The indications for TTE were as follows: ischaemic stroke or transient ischaemic attack (n =222; 11 with ischaemic heart disease); multiple sclerosis (n =44); dyspnoea (n =24); evaluation of various treatments (n =19); heart murmur exploration and control of valvular disease, endocarditis and suspicion of endocarditis (n =17); LVEF evaluation and/or heart failure (n =17); preoperative assessment (n =15); haemorrhagic stroke (n =13); hypertension (n =12); diabetes mellitus (n =11); assessment of the pericardium (n =5); occlusion of the central retinal artery (n =4); ischaemic heart disease (n =4); dissection of supra-aortic vessels (n =4); subarachnoid haemorrhage (n =3); assessment of arterial pulmonary pressures (n =3); control of LV thrombus (n =2); chest pain (n =2); pulmonary embolism (n =2); atrial fibrillation (n =2); arteritis of the lower limbs (n =1); Lyme disease (n =1); non-compaction cardiomyopathy (n =1); Sjögren's syndrome (n =1); sarcoidosis (n =1); intracerebral lesions (n =1). The other indications were classified as “miscellaneous”.

Clinical and echocardiographic characteristics of the first 507 patients have been reported elsewhere [3].

Echocardiographic analysis

TTE was performed using a commercial ultrasound system (Vivid 7; GE Healthcare, Horten, Norway), using a 4MHz transducer.

Standard TTE included LV analysis, LVEF calculation (Simpson's biplane method in patients in sinus rhythm; visual evaluation in patients in atrial fibrillation), tissue Doppler imaging, “naked eye” evaluation of LVWM and the calculation of LV GLS and segmental LPSS values. Firstly, a comprehensive analysis of cardiac anatomy was performed. Patient echogenicity was classified as 1 (good), 2 (moderate) or 3 (poor). The acoustic window had to be of sufficient quality to allow the calculation of LVEF, GLS and LPSS values and the visual evaluation of LVWM; otherwise, TTE was excluded.

Segments were classified on-line as 1 (normal), 2 (hypokinetic=2), 3 (akinetic), 4 (dyskinetic) or 5 (paradoxical [for the septum]).

As the aim of the study was to assess the value of segmental LPSS for the detection of LVWM abnormalities in a real-life echocardiography laboratory setting, there was no rereading by a second observer and no rereading by the same operator. All measurements were performed on-line, on the Vivid 7, without off-line analysis.

Speckle-tracking strain analysis

The three apical views (four-, two- and three-chamber views) were recorded with a frame rate between 70 and 80Hz, for the 2D-STE study. Myocardial deformation was assessed in a semiautomatic manner, based on grayscale images. The analysis was initiated through the apical three-chamber view, followed by the four- and two-chamber views. To initialize the analysis, three anatomical landmarks were set manually on each of the two points of the mitral annulus and on the apical endocardium. The software automatically placed the region of interest on the endocardial cavity. If the tracking was inadequate, manual adjustments were performed. As previously reported [1], each LV wall was divided into three segments: basal, mid and apical. Segmental LPSS values were hence obtained during the standard TTE.

Post-systolic shortening was not considered in this study. Figure 1 displays an example of output.



Figure 1


Figure 1. 

Longitudinal strain by speckle-tracking imaging in a heart failure patient. A. Measure of longitudinal strain using the apical two-chamber view, demonstrating peak longitudinal strain of –6.7%. B. Strain profiles from each apical view; average segmental values in each segment are used to generate a parametric bull's eye. 2CAV: two-chamber apical view; 4CAV: four-chamber apical view; APGAX: apical long-axis view.

Zoom

Statistical analyses

All values are presented as means±standard deviations, medians (interquartile ranges) or absolute numbers and frequencies.

LPSS values of normal basal, normal mid and normal apical segments were compared using the Wilcoxon signed rank sum test. The same analyses were performed for hypokinetic basal, hypokinetic mid and hypokinetic apical segments, and then akinetic basal, akinetic mid and akinetic apical segments.

To compare LPSS values at each level (basal, mid and apical), according to segmental kinetics, normal segments were labelled “1”, hypokinetic segments were labelled “2” and akinetic, dyskinetic and paradoxical segments were pooled into one sole category labelled “3”.

Analysis of variance was used for the comparisons between these three categories.

On logistic regression, the area under the receiver operating characteristic (ROC) curve (AUC) was analysed for LPSS values, in order to identify the threshold of LPSS that predicts abnormal segmental wall motion.

A P -value<0.05 was considered to be statistically significant, except for the multiple comparisons of mean LPSS values between normal and hypokinetic segments, normal and akinetic/dyskinetic segments and hypokinetic and akinetic/dyskinetic segments at each level (basal, mid and apical). Using the Bonferroni correction, only individual tests with P <0.0001 were considered to be significant.

Statistical analyses were performed using Stata® software, version 13 (StataCorp LP, College Station, TX, USA).

Results
Population and echocardiographic characteristics

Among the screened patients, 52 were excluded (33 had insufficient echogenicity and 19 had atrial fibrillation with important heart rate variability, precluding strain analysis); the study therefore involved 620 TTE scans. The main clinical and echocardiographic characteristics are reported in Table 1.

Distribution of LPSS values

A total of 11,160 segments were recorded, among which 11,111 segments were successfully tracked (99.6%) and entered the analysis.

Mean (95% confidence interval [CI]) segmental LPSS values for normal basal (n =3409), normal mid (n =3468) and normal apical (n =3466) segments were –16.7% (–16.9% to –16.5%), –18.2% (–18.3% to –18.0%) and –21.1% (–21.3% to –20.9%), respectively. The difference was significant between each two of them using the Wilcoxon signed rank sum test (Table 2).

These results are concordant with previous reports [1], and show significant differences between normal basal, normal mid and normal apical LPSS values, which decrease from basal to apical segments. Hence, abnormal segment LPSS values were analysed by segment location (basal, mid and apical) as shown in Figure 2, Figure 3, Figure 4.



Figure 2


Figure 2. 

Basal segments’ LPSS values by basal segments’ wall motion. Box-plot representation showing the distribution of LPSS values according to kinetics. The inbox line represents the mid value. The inbox circle represents the mean value. The edges of the box represent the 25th and 75th percentiles (Q1 and Q3), and the ends of the whiskers represent the upper and lower adjacent values, which are the most extreme values within Q3+1.5*(Q3–Q1) and Q11.5*(Q3–Q1), respectively. At first sight, normal LPSS values at the basal level differ from the LPSS values of abnormal segments.

Zoom



Figure 3


Figure 3. 

Mid segments’ LPSS values by mid segments’ wall motion. Same representation as in Figure 2.

Zoom



Figure 4


Figure 4. 

Apical segments’ LPSS values by apical segments’ wall motion. Same representation as in Figure 2.

Zoom

Mean (95% CI) segmental LPSS values for hypokinetic basal (n =114), hypokinetic mid (n =116) and hypokinetic apical (n =90) segments were –7.7% (–9.0% to –6.3%), –10.1% (–11.1% to –9.0%) and –9.3% (–10.5% to –8.1%), respectively (Table 2). The difference was significant between each two of them.

Mean (95% CI) segmental LPSS values for akinetic basal (n =128), akinetic mid (n =95) and akinetic apical (n =91) segments were –6.6% (–8.0% to –5.1%), –6.1% (–7.7% to –4.6%) and –4.2% (–5.4% to –3.0%), respectively (Table 2), with only the first two being significantly different (P =0.0137).

Using the analysis of variance test, the F statistic value was significant for each comparison of segmental LPSS values according to the kinetics (categories 1, 2 and 3) at each level (basal, mid and apical). Hence, the mean LPSS segmental basal, mid and apical values were not all equal in the three categories of kinetics.

Using multiple comparisons at each level (basal, mid and apical), mean LPSS values differed significantly (Bonferroni correction, P <0.0001) between normal versus hypokinetic segments, normal versus akinetic/dyskinetic segments and hypokinetic versus akinetic/dyskinetic segments. The only exception was the absence of significant difference between hypokinetic and akinetic/dyskinetic segments at the basal level (P =0.38).

Hence, among basal segments, LPSS values allowed the differentiation between normal and hypokinetic and normal and akinetic/dyskinetic segments, but could not differentiate between hypokinetic and akinetic segments.

On logistic regression, the AUC was analysed for LPSS values, in order to identify the threshold of LPSS that predicts abnormal segmental wall motion. Figure 5 displays ROC curve analyses at basal, mid and apical levels, respectively. The mean (95% CI) AUCs were 0.853 (0.831–0.874), 0.879 (0.856–0.903) and 0.951 (0.939–0.963), respectively, the best prediction of the model being reached for apical segments. An LPSS value–12% allowed detection of abnormal segmental motion with a mean (95% CI) sensitivity of 78% (73–82%) for basal segments, 70% (63–75%) for mid segments and 82% (77–87%) for apical segments. The mean (95% CI) specificities were 81% (80–83%), 90% (89–91%) and 92% (91–93%), respectively.



Figure 5


Figure 5. 

Receiver operating characteristic (ROC) curves. A. For basal segments, the area under the ROC curve (AUC) for basal LPSS values is 0.8525. B. For mid segments, the AUC for mid LPSS values is 0.8792. C. For apical segments, the AUC for apical LPSS values is 0.9511.

Zoom

Discussion

Our study of 620 consecutive patients undergoing standard TTE performed by the same experienced operator in routine real-life practice has confirmed the feasibility of 2D-STE analysis on-line, requiring no off-line analysis, 99.6% of the segments being successfully tracked.

We found a relationship between LVWM abnormalities and reduced strain, with an LPSS cut-off value of –12% to detect abnormal segmental motion with reasonable sensitivities of 78% for basal, 70% for mid and 82% for apical segments; the specificities were excellent (81%, 90% and 92%, respectively). These results are particularly interesting because LV segmental function assessment is a major issue when performing echocardiography.

We believe that two points deserve to be discussed. Firstly, why is a comparison made between strains that assess deformation with LVWM, which is mainly due to thickening and not necessarily to longitudinal contraction? As described [5], there is a real relation between myocardial function (contractility) and the resulting motion/deformation. The main factors influencing regional myocardial deformation have been described as an active force (contractility), two passive forces (pressure and segment interaction) and the tissue properties.

Second, it is remarkable that akinetic segments still have –6% strain values (for basal and mid segments); this is probably because the segments identified by the naked eye and the segments used in speckle tracking are not the same. This is a fundamental problem in the current implementation of speckle tracking when “standard” segments are used and are not individually adjusted. When assessing wall motion by eye, one automatically adjusts the segment size/position to the patient. However, when doing speckle tracking, the ventricle is just divided into segments (six equal segments in the software used here), which means that there is usually much more smoothing out of the strain value.

LVWM evaluation

Among the clinical applications of TTE, an important one is the stratification of patients with acute chest pain, as the absence of abnormal LVWM abnormalities during pain or shortly after identifies patients at low risk [6]. To date, the gold standard technique for this stratification is expert “naked eye” evaluation; however, this is prone to important intra- and interobserver variability, which increase when the operator is less experienced [1]. We emphasize here the importance of clinical training and experience for adequate “naked eye” segmental analysis of LV walls on TTE. Level 2 training (6 months, performance of 150 examinations and interpretation of 300 examinations) is the minimum recommended training for a physician to perform and interpret echocardiograms independently. Of note, a good stress echocardiogram “naked eye” interpretation requires Level 2 training and additional specialized training in stress echocardiography, with performance and interpretation of 100 stress studies under appropriate supervision by a Level 3 echocardiographer [7]. Quantitation is one of the proposed solutions to reduce variation in interpretation, and the availability of a simple quantitative variable to support the clinician's interpretation of resting echocardiography images would be an important step forward [8].

LV quantitative evaluation

Several quantitative techniques have emerged in recent decades to address the issue of reader experience and intermeasurement variability in interpretation. Some of these techniques have been widely embraced, and have become part of routine clinical practice, while others remain limited to the research and exploration of new clinical applications. Two such techniques have dominated the echocardiography research arena: tissue Doppler imaging and STE [9].

STE was developed as an off-line technique for the quantitative analysis of myocardial deformation; it is applied to previously acquired two-dimensional (2D) images. To estimate tissue movement, 2D-STE uses frame-by-frame image tracking; it is an angle-independent technique. As strain values are obtained semiautomatically, they are less operator-dependent than “naked eye” evaluation; hence, we may expect a shorter learning curve. While 2D-STE used to require a time period to elapse post treatment, a study with a small sample size recently assessed the feasibility of 2D-STE for the evaluation of real-time strain and strain rate [10], as did a larger study that assessed GLS [3], demonstrating that on-line evaluation of myocardial deformation is possible today. Our current study confirms this finding.

Tissue Doppler imaging also allows the measurement of myocardial velocities, strain and strain rate in a clinical setting [11]. However, this technique best assesses myocardial velocities when single-dimension motion is investigated, while the heart has a complex motion pattern. Furthermore, angle dependency is an important pitfall.

While tissue Doppler imaging velocities are significantly higher at the basal level than the apical level in normal subjects, the base of the heart descending towards the apex during systole and the apex being nearly stationary [11], there are discordant data concerning normal segmental LPSS values, and different techniques provide variable results. These values have been described as relatively uniform throughout the LV [10] or as being higher at the apical level [1]. Our study is consistent with the latter scenario, demonstrating significantly higher apical LPSS values than mid LPSS values, and significantly higher mid LPSS values than basal values. This finding is difficult to explain, and might be multifactorial, including issues of signal intensity, curvature and myocardial architecture [1].

Recent studies have evaluated the contribution of 2D-STE as a support for “naked eye” evaluation of LVWM [12, 13]. Our results are in agreement with the latest study [13], which demonstrated the efficiency of 2D-STE for detecting LVWM abnormalities, defining temporary criteria for LPSS values as follows: normal segments had LPSS values<–12%, hypokinetic segments had values between –12% and 2% and akinetic segments had values>2%. These temporary criteria had a 97% success rate. However, these results are based on 22 patients and 342 segments, representing a small population. The two works also differ in that our results are provided according to segment levels, while the preceding study [13] did not take the level of the analysed segments into consideration, and their measurements were not made on-line as part of routine clinical practice.

We hence confirm, in a large series, an LPSS cut-off value of –12% to best differentiate normal from abnormal segments, and have shown that this technique is applicable in real-life practice.

Potential clinical applications

The evaluation of LVWM is a key step in echocardiography. However, in the absence of reliable and reproducible tools for LVWM quantification, it remains very dependent on the operator's qualification and experience.

While 2D-STE is sufficiently standardized, and has been applied to several cardiac conditions, its place in daily ultrasound practice has not yet been clearly defined by the guidelines [14]. As TTE is now widely used by non-cardiologists [15], because of its portability, 2D-STE may be useful for detecting abnormal segmental wall motion using a segmental LPSS cut-off value of –12%, especially when TTE is performed by novice echographers, or in emergency rooms and intensive care units.

Study limitations

First, all measurements were performed on-line without off-line processing, and there was no rereading by a second observer. However, this was part of the philosophy of this study, which aimed to assess the feasibility of 2D-STE and its contribution to the interpretation of TTE results and the detection of LVWM abnormalities under real-life conditions, on consecutive patients. Furthermore, the 2D strain analysis was not blinded to the visual assessment of LVWM.

Second, the LPSS values reported here might only be true with the equipment used in this study (Vivid 7), and might be slightly different on more recent echocardiography machines, thanks to continuous improvements in image quality and speckle-tracking software. The European Association of Cardiovascular Imaging and the American Society of Echocardiography, recognizing the critical need for standardization in strain imaging, have provided a technical document to create a common standard [16].

Third, many factors related to the image-processing method may influence LPSS values, as reported previously [1]; some of these factors are position of basal points, excessive region-of-interest width and, by contrast, insufficient region-of-interest width. Hence, the 2D-STE method needs training, even if this is expected to be shorter than the training recommended for the “naked eye” method [7].

Fourth, the mean LV mass indexed to body surface was 95.9±32.0g/m2 in our study; a higher rate of LV hypertrophy would probably have an impact on LPSS values.

Fifth, there was no gold standard to evaluate whether expert “naked eye” or 2D-STE is better.

Finally, this study included 13% of patients with suboptimal echogenicity, which may have modified the normal ranges. Furthermore, a poor acoustic window may result in suboptimal image quality, with resultant poor endocardial tracking and falsely low strain results. Imaging of adequate quality is important to perform 2D-STE, as it is more sensitive to suboptimal image quality than expert “naked eye” evaluation.

Conclusions

TTE is the most commonly used tool for the detection of LVWM abnormalities using “naked eye” evaluation. To be accurate, this operator-dependent technique requires a high level of clinical training and extensive experience. 2D-STE echocardiography is less operator-dependent. This study demonstrated that on-line semiautomated measurement of segmental LPSS using 2D-STE is feasible in routine echocardiographic practice.

Although not yet ready to replace expert “naked eye” evaluation, 2D regional longitudinal strain seems to be helpful, in association with less expert visual evaluation, for LVWM assessment. Hence, it could be used practically by less experienced operators in the visual recognition of regional wall motion abnormalities, especially in emergency and intensive care departments and in operating rooms.

Funding

None.

Disclosure of interest

A.C.: honoraria or research support from the companies Bayer, BMS, Boehringer Ingelheim, RESICARD network and Sanofi, but no conflicts of interest concerning this article.

S.L.: travel grants from the company BMS, but no conflicts of interest concerning this article.

The other authors declare that they have no competing interest.


Acknowledgments

The authors wish to thank Mrs Vanessa Badja for bibliographical assistance.

References

Marwick T.H., Leano R.L., Brown J., and al. Myocardial strain measurement with 2-dimensional speckle-tracking echocardiography: definition of normal range JACC Cardiovasc Imaging 2009 ;  2 : 80-84 [cross-ref]
Altman M., Bergerot C., Aussoleil A., and al. Assessment of left ventricular systolic function by deformation imaging derived from speckle tracking: a comparison between 2D and 3D echo modalities Eur Heart J Cardiovasc Imaging 2014 ;  15 : 316-323 [cross-ref]
Benyounes N., Lang S., Soulat-Dufour L., and al. Can global longitudinal strain predict reduced left ventricular ejection fraction in daily echocardiographic practice? Arch Cardiovasc Dis 2015 ;  108 : 50-56 [cross-ref]
Szulik M., Pappas C.J., Jurcut R., and al. Clinical validation of a novel speckle-tracking-based ejection fraction assessment method J Am Soc Echocardiogr 2011 ;  24 : 1092-1100 [inter-ref]
Bijnens B.H., Cikes M., Claus P., Sutherland G.R. Velocity and deformation imaging for the assessment of myocardial dysfunction Eur J Echocardiogr 2009 ;  10 : 216-226
Muscholl M.W., Oswald M., Mayer C., von Scheidt W. Prognostic value of 2D echocardiography in patients presenting with acute chest pain and non-diagnostic ECG for ST-elevation myocardial infarction Int J Cardiol 2002 ;  84 : 217-225 [cross-ref]
Quinones M.A., Douglas P.S., Foster E., and al. ACC/AHA clinical competence statement on echocardiography: a report of the American College of Cardiology/American Heart Association/American College of Physicians-American Society of Internal Medicine Task Force on Clinical Competence J Am Coll Cardiol 2003 ;  41 : 687-708 [cross-ref]
Marwick T.H. The future of echocardiography Eur J Echocardiogr 2009 ;  10 : 594-601 [cross-ref]
Mor-Avi V., Lang R.M., Badano L.P., and al. Current and evolving echocardiographic techniques for the quantitative evaluation of cardiac mechanics: ASE/EAE consensus statement on methodology and indications endorsed by the Japanese Society of Echocardiography Eur J Echocardiogr 2011 ;  12 : 167-205 [cross-ref]
Leitman M., Lysyansky P., Sidenko S., and al. Two-dimensional strain-a novel software for real-time quantitative echocardiographic assessment of myocardial function J Am Soc Echocardiogr 2004 ;  17 : 1021-1029 [inter-ref]
Edvardsen T., Gerber B.L., Garot J., Bluemke D.A., Lima J.A., Smiseth O.A. Quantitative assessment of intrinsic regional myocardial deformation by Doppler strain rate echocardiography in humans: validation against three-dimensional tagged magnetic resonance imaging Circulation 2002 ;  106 : 50-56 [cross-ref]
Kataoka A., Funabashi N., Yajima R., and al. Differentiation of pseudodyskinesis of inferior left ventricular wall from inferior myocardial infarction by assessment of regional myocardial strain using two-dimensional speckle tracking echocardiography Int J Cardiol 2011 ;  152 : 362-368 [cross-ref]
Takahashi M., Harada N., Isozaki Y., and al. Efficiency of quantitative longitudinal peak systolic strain values using automated function imaging on transthoracic echocardiogram for evaluating left ventricular wall motion: new diagnostic criteria and agreement with naked eye evaluation by experienced cardiologist Int J Cardiol 2013 ;  167 : 1625-1631 [cross-ref]
McMurray J.J., Adamopoulos S., Anker S.D., and al. ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure 2012: the Task Force for the diagnosis and treatment of acute and chronic heart failure 2012 of the European Society of Cardiology. Developed in collaboration with the Heart Failure Association (HFA) of the ESC Eur Heart J 2012 ;  33 : 1787-1847
Lang R.M., Bierig M., Devereux R.B., and al. Recommendations for chamber quantification Eur J Echocardiogr 2006 ;  7 : 79-108 [cross-ref]
Voigt J.U., Pedrizzetti G., Lysyansky P., and al. Definitions for a common standard for 2D speckle tracking echocardiography: consensus document of the EACVI/ASE/Industry Task Force to standardize deformation imaging J Am Soc Echocardiogr 2015 ;  28 : 183-193 [inter-ref]



© 2016  Elsevier Masson SAS. All Rights Reserved.
EM-CONSULTE.COM is registrered at the CNIL, déclaration n° 1286925.
As per the Law relating to information storage and personal integrity, you have the right to oppose (art 26 of that law), access (art 34 of that law) and rectify (art 36 of that law) your personal data. You may thus request that your data, should it be inaccurate, incomplete, unclear, outdated, not be used or stored, be corrected, clarified, updated or deleted.
Personal information regarding our website's visitors, including their identity, is confidential.
The owners of this website hereby guarantee to respect the legal confidentiality conditions, applicable in France, and not to disclose this data to third parties.
Close
Article Outline