Copyright © 2005, The European Society of Cardiology
Feasibility of strain and strain rate imaging for the assessment of regional left atrial deformation: A study in normal subjects
aDepartment of Cardiology, Cardiac Imaging Research, KU Leuven, University Hospital Gasthuisberg, Herestraat 49, B-3000 Leuven, Belgium
bDepartment of Cardiology, St. George's Hospital, London, UK
Received 23 November 2004; received in revised form 15 May 2005; accepted after revision 1 June 2005.
* Corresponding author. Tel.: +32 16 347565; fax: +32 16 344240. cristina.sirbu{at}uz.kuleuven.ac.be
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Abstract |
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Aims There are no data on the use of Myocardial Velocity Imaging (MVI) to study the left atrium (LA) wall deformation. The aims of this study were to assess the feasibility of measuring regional longitudinal strain/strain rate (
/SR) profiles in the LA wall, to define the normal values and to validate these measurements.
Methods and results MVI data were recorded in 40 healthy young individuals using a GE Vivid7 for the lateral, anterior and inferior LA walls. The peak /SR values and total values during the contractile, reservoir and conduit LA phases were measured. For the LA lateral wall, the total values were correlated with the LA volumetric indicators (LA active emptying fraction: LA AEF; LA expansion index: LA EI; and LA passive emptying fraction: LA PEF). The correlations were significant for all three periods: contractile (total vs. LA AEF, r=–0.78, P<0.001), reservoir (total vs. LA EI, r=0.43, P<0.01) and conduit (total vs. LA PEF, r=–0.46, P<0.005).
Conclusion SR/ imaging for the quantification of longitudinal myocardial LA deformation was shown to be feasible and the normal values were reported and validated. These data may improve the understanding of the LA pathophysiology.
Keywords: MVI; myocardial velocity imaging; SR; strain rate; ; strain; SPEQLE; Software Package for Echocardiographic Quantification Leuven; LA; left atrium; LV; left ventricle; Vpre A; left atrial volume pre-atrial contraction; Vmin; left atrial minimal volume; Vmax; left atrial maximal volume; LA AEF; left atrial active emptying fraction; LA EI; left atrial expansion index; LA PEF; left atrial passive emptying fraction; PE; pre-ejection; AE; atrial ejection; IVC; isovolumic contraction; IVR; isovolumic relaxation; EF; early ventricular filling; D; diastasis; CT; contractile period; ER; early reservoir period; LR; late reservoir period; CD; conduit period
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Introduction |
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The left atrium (LA) plays an important role in the overall cardiovascular performance. This is accomplished through its action as a contractile chamber during late ventricular diastole, as a reservoir distended by the inflow volume from pulmonary veins during ventricular contraction and isovolumic relaxation and as a conduit during the early ventricular diastole and diastasis.1
The study of the LA cavity by conventional echocardiography through the two-dimensional (2D) measurements of the LA volumes and of the LA blood flow through the pulsed Doppler mitral inflow or pulmonary vein flow parameters substantially advanced our understanding of LA function in the normal and diseased heart.2–4 However, the major limitation of these techniques is the lack of a gold standard measurement of LA function. To expand the conventional echocardiographic methods, there is an increasing interest in new objective and non-invasive measures for the assessment of atrial myocardial function. Since new techniques have become available, a need for normal values and a validation of these methods is essential.
Myocardial Velocity Imaging (MVI) can be used for the quantification of regional ventricular myocardial motion by measuring the velocity and direction of regional myocardial motion. Post-processing of the MVI data allows the quantification of regional strain rate (SR) and strain (). SR corresponds to the speed at which myocardial deformation occurs (expressed in s–1). Regional values can be obtained by integrating SR over time and represent the relative amount of local deformation.5–7
It has been shown that longitudinal SR/ can be measured in all left ventricular (LV) and right ventricular (RV) segments using the apical 2-, 3- and 4-chamber views. The radial SR/ can be obtained only from the inferior and infero-lateral walls of the LV using a parasternal short- or long-axis view.8,9 However, to date, there are no data regarding the availability of these techniques for the study of the LA wall deformation.
For longitudinal motion of the LA wall the velocities profiles can be derived using both pulsed and colour MVI from all portions of the LA wall. The LA segments adjacent to the mitral ring have highest velocities in the LA wall.10 However, as motion is influenced by tethering, those methods are not optimal for the assessment of regional myocardial function.7 In order to overcome these limitations, tissue deformation imaging has been introduced.6,7,9 However, an accurate assessment of myocardial deformation in the interatrial septum cannot be performed due to its structure (combination of fibrous and muscular tissue). Moreover, because the LA is thin, the radial deformation cannot be calculated as the spatial resolution of the current methods is limited.7 Nevertheless, with the current available technology, we expect that the longitudinal deformation of the LA wall can be measured but to date no studies are available.
Therefore, the aims of this study were: (a) to assess the feasibility of measuring regional longitudinal SR/ profiles in the LA walls; (b) to define the normal values for the LA lateral, anterior and inferior walls in healthy young subjects; and (c) to validate these data by correlating them with the standard indicators for LA function derived from volumetric measurements.
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Methods |
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Study population
A total of 40 healthy young individuals (age 17–37, mean 29.35±4.8; 15 women, 25 men) underwent a standard transthoracic echocardiography (TTE) followed by a colour MVI study at rest. None of the subjects had a history of cardiac disease or were on cardioactive medication. All subjects were in sinus rhythm and showed no abnormalities on ECG. For all, grey-scale 2D echo images showed normal cardiac function on visual inspection. Their mean heart rate was 67±12 bpm. All examinations were carried out in accordance with the regulations of the ethical committee of the University Hospital Gasthuisberg, Leuven.
Echocardiographic study
Standard transthoracic echocardiographic study
The echocardiographic examinations were performed with a GE Vivid7 scanner (GE Medical Systems, Horten, Norway) equipped with a 3.4MHz phased array transducer. For data acquisition, three complete cardiac cycles were collected and stored in a cine-loop format. Data were acquired with the subjects at rest, lying in the lateral supine position. From 2D echocardiography, in apical 4-chamber view, the Simpson method11–13 was used to calculate the following indices: (1) pre-atrial contraction LA volume (VpreA), measured at the onset of P wave on the ECG; (2) minimal LA volume (Vmin), measured at the closure of the mitral valve; (3) maximal LA volume (Vmax), measured just before the opening of the mitral valve. Special attention was paid to start/end tracing at the mitral annulus and to omit pulmonary veins in the tracing.14 For the assessment of the LA function three indicators derived from volumes were used: LA active emptying fraction (LA AEF)=(VpreA–Vmin)/VpreAx100; LA expansion index (LA EI)=(Vmax–Vmin)/Vminx100; and LA passive emptying fraction (LA PEF)=(Vmax–VpreA)/Vmaxx100.15 The left ventricular (LV) systolic function was assessed using the LV ejection fraction (EF), calculated with the Simpson method. Blood pool pulsed Doppler recordings were obtained from the mitral valve inflow and from the left ventricular outflow tract immediately proximal to the leaflets of the aortic valve in apical 4-chamber and 5-chamber views. The following transmitral Doppler flow parameters were measured: the peak velocity of E and A waves, the E/A ratio and the deceleration time of the E wave (DT). The isovolumic relaxation time (IVRT) was measured as the interval between the aortic valve closure and the onset of transmitral flow.
Colour MVI study
Colour MVI data were acquired at a frame rate of 160–200 s–1, using a narrow sector angle (30°), at the end of expiration. The recorded wall was positioned in the centre of the sector to minimize artefactual data and re-aligned so that the direction of motion interrogated was as near as possible parallel to the direction of the insonating beam. The colour MVI range setting was adapted in order to avoid aliasing within the image.7 The longitudinal SR/ were measured in the mid portion of the lateral LA wall (from the apical 4-chamber view) and the anterior and inferior walls (from the apical 2-chamber view). The SR/ profiles were extracted and analysed using dedicated software (SPEQLE, Catholic University Leuven, Belgium). SR profiles within the mid segment of the three LA walls were obtained by tracking that segment during the cardiac cycle. The myocardial profiles were calculated by integrating the SR profiles over time and compensating for drifting over the cardiac cycle.
The periods of the cardiac cycle defined after the /SR profiles for longitudinal deformation of the LA wall were aligned with the blood pool pulsed Doppler profiles of transmitral flow and LV outflow tract, starting with the P wave on ECG. Thus, the time interval between the onset of P wave on ECG and the onset of the A wave of transmitral inflow represents the LA electromechanical coupling. The LA contractile period was defined as A-wave duration, the LA reservoir period as the interval between the mitral valve closure (MVC) and mitral valve opening (MVO), and the LA conduit period as the interval between MVO and the onset of the A wave. During the LA reservoir period the LV mechanical events are: the isovolumic contraction (IVC), between MVC and aortic valve opening (AVO); the LV ejection (E), between AVO and aortic valve closure (AVC); and isovolumic relaxation (IVR), between AVC and MVO. The LA conduit period corresponds to LV early filling (EF) (measured as the E-wave duration) to diastasis and to LA electromechanical coupling.
The longitudinal LA wall deformation was assessed by measuring the peak values for SR and during the contractile, reservoir and conduit phase, using dedicated software (SPEQLE). The value of total during each period was measured as the difference of deformation between the onset and the end points of the period. Also, the onset, the time to peak LA wall deformation assessed by and by SR (from the beginning of the P wave) and the duration of each period were calculated. The results obtained from the three LA walls were compared.
The total values for the three periods of the LA lateral wall were correlated with the LA functional indicators derived from volumetric changes (LA AEF, LA EI, LA PEF).
Reproducibility
Observer agreement
Intra-observer and inter-observer variability were assessed separately for each of the /SR indices calculated. Eleven datasets were randomly selected and analysed. For the assessment of intra-observer variability the analyses were repeated twice by the same observer within 1week. For the inter-observer variability assessment, a second independent observer repeated the analyses.
Study agreement
Inter-study variability was assessed for five datasets recorded and analysed twice by the same observer within 24h.
Statistical analysis
Results are reported as means±standard deviations. The different /SR indicators for the longitudinal deformation of the LA wall were compared between the anterior, lateral and inferior walls with repeated-measures ANOVA followed by post hoc comparisons using t-tests corrected according to Bonferroni. The Pearson product moment correlation coefficient (r) was used to measure the strength of the association between the LA volume change indicators and the parameters. A P value of <0.05 was considered statistically significant. The estimation of intra-observer, inter-observer and inter-study reproducibility was performed using the Bland–Altman analysis.16 The relative mean differences were calculated between paired measurements. The 95% confidence interval was calculated and reported both as an absolute value and as a percentage of the mean value.16
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The general and standard echocardiographic characteristics of the study population are presented in Table 1 and show normal values according to their age. In all 40 subjects consistent patterns of longitudinal wall deformation for all the three walls were obtained.
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Fig. 1 presents an example of
/SR profiles for LA wall longitudinal deformation.
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/SR indicators for LA contractile periodFor the
profile of the LA contractile period (CT) the onset (point 1), the peak (point 2) and the end (point 3) are indicated (Fig. 1). The peak SR is also represented (point 2'). Thus, during the LA contractile period, the LA myocardium shortens to a peak value that occurs before the end of the period (point 2) and then starts to lengthen. The peak values for SR and during the contractile period as well as the total during this period for the three LA walls are presented in Table 2.
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For peak SR there was a significant difference between the three walls; F(2,78)=5.48, P=0.005, with the value for the inferior wall (M=–4±1.2s–1) significantly lower than the anterior (M=–5.1±1.6s–1) (P=0.01) and lateral (M=–4.9±1.8s–1) (P=0.02) LA walls.
A significant difference between walls was obtained for the peak values [F(2,78)=3.98, P=0.02], with the value for the inferior wall (M=–21.5±7.4%) significantly lower than the value for the lateral wall (M=–25.43±7.73%) (P=0.01).
/SR indicators for LA reservoir period
For the profile of the LA reservoir period (R) the onset (point 3), the peak (point 4) and the end (point 5) are shown in Fig. 1. The SR profile, although more ‘noisy’, allows to identify two peaks: one during the IVC period (point 4') and the other during the E period (point 4''). These two peaks allow to divide the LA reservoir period into two phases: early (ER), corresponding to the IVC period, and late (LR), during E+IVR period.
For the reservoir period the profiles indicated atrial myocardial lengthening with a peak value occurring during the LV ejection (E) period (point 4), followed by the beginning of shortening (Fig. 1). The peak SR corresponding to the early reservoir (ER) is opposed to the peak SR for the contractile period (indicating also lengthening). The peak SR during the late reservoir (LR) occurs during the LV ejection (Fig. 1). The peak values of SR/ for the reservoir period and the total value of during this period are shown in Table 2.
During the early reservoir period (ER) there was a significant difference between the three walls for the peak SR [F(2,78)=3.75, P=0.02], with the value for the inferior wall(M=4.2±2.1s–1) significantly lower than the lateral wall (M=5.45±2.85s–1) (P=0.03).
/SR indicators for LA conduit period
For the conduit period the profiles indicated atrial myocardial shortening with a peak value (point 6) during early LV filling (EF). The LA wall deformation ends during the diastasis (D) (point 7). The peak SR occurs also during the early LV filling (point 6') (Fig. 1). Table 2 presents the peak /SR values and the total value for the three LA walls.
A significant difference between the three walls was obtained for the peak SR [F(2,78)=6.22, P=0.003], with the value for the inferior wall (M=–5.42±1.91s–1) significantly lower than the value for the lateral wall (M=–7.48±3.44s–1) (P=0.002). The peak was also significantly different between walls, F(2,78)=3.82, P=0.02, with the value for the inferior wall (M=–36.5±13%) significantly lower than the value for the lateral wall (M=–41.72±16.7%) (P=0.04).
Timing analysis
For each of the three LA periods, the onset, the time to peak LA wall deformation and the duration of the period are shown in Table 3. The time to peak SR was shorter than the time to peak .
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Moreover, for the contractile period the time to peak SR was significantly different between the three LA [F(2,78)=8.24, P=0.0005]. The peak SR occurred significantly later for the inferior wall (123±22ms) than for the anterior wall (107±25ms) (P=0.0004) and for the lateral wall (117±23ms) (P=0.03). For the reservoir period, during the early reservoir phase significant differences between walls were obtained [F(2,78)=3.87, P=0.02]. The peak SR occurred significantly later for the inferior wall (225±32ms) than for the lateral wall (210±31ms) (P=0.02). During the late reservoir period as well as the conduit period, there were no significant differences between the LA walls.
Observer variability
Table 4 shows intra-observer and inter-observer agreement assessed separately for each parameter of LA wall deformation. For the contractile period intra-observer variability for peak was 10.61% and for total 9.44%, while the inter-observer variability was 11.46% and 10.22%, respectively. Intra-observer variability for peak SR was 2.47% and the inter-observer variability 2.12%. For the reservoir period both the intra-observer and inter-observer variability were low for the peak values 6.85% and 7.31% and for total values 6.24% and 6.3%, while for the peak SR during the early reservoir the variability was higher 14.17% and 18.28% as well as for the peak SR during the late reservoir period 17.12% and 31%. Intra-observer and inter-observer variability for the conduit period were also good for peak 11.62% and 14.36% and for total 6.59% and 6.58%, while the variability for peak SR was higher 24.11% and 27%. The intra-observer and inter-observer variability of timing measurements for the /SR indicators of LA longitudinal wall deformation are presented in Table 6.
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Study variability
In Table 5 the inter-study agreement for the
/SR parameters is indicated. For all three LA periods the inter-study variability was good for the peak and total values as well as for the peak SR values. Table 7 shows the inter-study agreement for the time to peak and SR for each of the three LA periods.
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Comparison of LA wall deformation with LA volume changes
The volume indicators for the LA function derived from standard transthoracic echocardiography are presented in Table 8.
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For the LA contractile period, the total
value correlated significantly (r=–0.78, P<0.001) with LA AEF (indicator of the atrial ejection performance) (Table 9). The total value of for the reservoir period correlated significantly with the LA volume change during the LA filling (LA EI) (r=0.43, P<0.01) (Table 9). During the conduit period the total correlated significantly(r=–0.46, P<0.005) with LA PEF (Table 9).
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Discussion |
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SR and
are new ultrasound indices for the quantification of regional ventricular wall deformation. The normal regional SR/ values for both radial and longitudinal ventricular deformation were defined in prior studies.5,17 MVI has been more widely used in the evaluation of ventricular function.18 To date, there are no data about the assessment of regional LA deformation and function by SR/ imaging. This study suggests an additional role in the assessment of the LA myocardial properties.
Our results demonstrate that SR/ imaging is feasible for the quantification of longitudinal myocardial LA deformation. Moreover, the normal values for the different LA walls (lateral, anterior and inferior) for a young study population are defined. The reproducibility of measurements was good, especially for the peak and total values. The inter-observer and intra-observer variability for the /SR indicators of LA wall deformation were comparables with that for the LV wall deformation.5 Thus, /SR imaging may be used for the assessment of atrial and ventricular regional myocardial deformation.
The SR/ profiles followed LA physiology. The LA wall shortens during the LA contraction that permits the emptying of the blood into both the LV and the pulmonary veins. During the LA reservoir the SR profile and timing allow to define two phases: early (corresponding to IVC period) and late (corresponding to E and IVR periods). During both phases the profile showed lengthening corresponding to LA filling from the pulmonary veins. The LA conduit facilitates the LV filling by LA wall shortening during the EF period. Subsequently, during the diastasis both the /SR profiles are flat, demonstrating that no LA wall deformation occurs in the late phase of the conduit period.
The comparative assessment of the three LA walls showed significant differences. Thus, the SR profile provided the lowest peak value for the inferior LA wall with statistically significant differences compared to the anterior and lateral walls during the contractile period and compared to the lateral wall during the conduit period. Corresponding to these differences, the time to peak SR was significantly longer for the inferior wall during the contractile period. The peak values were significantly lower for the inferior than the lateral LA wall during both the contractile and conduit periods. During the early reservoir period the peak SR showed also significant lower values for the inferior compared to the lateral wall. Also, for the early reservoir period the peak SR occurred significantly later. No differences between the LA walls for the peak SR values were observed during the late reservoir period.
This may be related to the LA activation. It was shown that the LA activation pattern is complex and is determined by a principal line of conduction block descending on the inferior LA wall from the roof, passing between the ostia of the superior and inferior pulmonary veins, turning septally, then passing below the fossa ovalis and merging anteriorly with the septal mitral annulus.19 Histological studies revealed that this line corresponds to a change in subendocardial fibre orientation from longitudinal orientation septal to the line to oblique and circumferential lateral to the line. This line also marked a change in the inferior LA wall; this being thicker toward the septum and thinner laterally.19 This suggests a physiological difference between the LA walls that is also reflected in differences in peak /SR values. The peak SR during the late reservoir period occurs during the LV ejection, suggesting an influence of the LV systole to this reservoir phase. This influence can explain the absence of the differences in the peak /SR values between the three LA walls during the late reservoir.
The histological features of the LA inferior wall also suggest that the deformation of this wall may not be homogeneous.
Multiple studies have examined LA function, but the main inconvenience for the quantitative assessment is the requirement of invasive pressure–volume diagrams that do not allow routine clinical use.20–22 From non-invasive techniques a variety of indices were examined, but the approaches are complex and the accuracy of these parameters is limited.23–25 The 2D echocardiographic LA volumes have been proposed as indicators of atrial size, but some potential sources of error related to the geometric assumptions remain to be corrected.11,26
Nevertheless, 2D echocardiography provides an accurate measurement of LA volumes when compared to 3D echocardiography and is the method of choice for clinical routine due to its repeatability and large accessibility.27 For the estimation of the LA volume, the Simpson method has shown a higher correlation with angiography and computed tomography.26,27 In our study the measurement of LA volumes by the Simpson method allowed to define three volume indicators that can be used to describe the LA contractile (LA AEF), reservoir (LA EI) and conduit (LA PEF) function.
From a geometric standpoint a correlation between the total strain and the fractional volume changes during the different mechanical phases of the LA was expected. During the LA contractile period the total value of was correlated with LA AEF, the fractional decrease of the LA volume and indicator of LA ejection performance. Thus, the regional magnitude of deformation expressed by the total value of was related to global LA ejection performance assessed by LA AEF. For both, and SR profiles the peaks occurred before the end of the LA contractile period, indicating that the relaxation of the LA wall starts before the mitral valve closure. This may favour the early systolic peak flow velocity (S1) of the pulmonary venous flow that normally occurs during the early reservoir period.28
The use of SR/ imaging for the study of LA reservoir period shown that the total value of during this period was correlated significantly with LA EI. The profile peaks during the late reservoir phase that corresponds to LV ejection period, suggesting a contribution of the LV systole to the LA wall lengthening.
During the LA conduit period, the LA empties into the LV and refills from the pulmonary veins. This implies a rapid LA wall shortening in the early conduit phase, after the LA wall stretching during the preceding reservoir phase. Therefore, the LA expansion during the reservoir phase may be an important factor for maintaining adequate LV filling.
Furthermore, we were able to show that during the conduit period the total value of was correlated with LA PEF.
Thus, the SR/ profiles reflect the longitudinal deformation of the LA wall during the cardiac cycle, as was shown by the correlations between the total during the periods and the corresponding volume fractions.
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This study was based only on a small group of healthy subjects and thus, the age range selected may be considered as representative only for the young adult healthy population.
The radial LA wall deformation was not analysed because the LA wall is too thin for the spatial resolution of the current techniques. The assessment of LA function based on volumes, although validated using invasive techniques, is still limited by the subjective character of LA endocardial border tracing. This can explain the low correlations between the volume changes during the reservoir and conduit periods and the total values. Cine magnetic resonance imaging allows direct acquisition of the 3D LA volumes without resorting to any geometric assumption, but its routine use in clinical settings has been hampered by prolonged post-processing time. An evaluation of the pressure–volume relationship in correlation with the SR/ indices for the LA function as well as an assessment of LA compliance allowed a better explanation of the SR/ profiles. This was not possible as no invasive procedures were performed in these normal subjects. For the same reasons an electrophysiological assessment of the LA walls activation in comparison to the colour MVI was not possible.
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Conclusions |
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TopAbstractIntroductionMethodsResultsDiscussionLimitationsConclusionsReferences |
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SR/
imaging for the quantification of longitudinal myocardial LA deformation was shown to be feasible. Moreover, normal values for the lateral, anterior and inferior walls were reported for a young study population. These values correlate with the indicators derived from volumes by standard transthoracic echocardiography. As a consequence, SR/ imaging can be considered a robust technique for the non-invasive assessment of the LA deformation and the understanding of the LA pathophysiology. |
References |
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- Pagel P.S., Kehl F., Gare M., Hettrick D.A., Kersten J.R., Warltier D.C. Mechanical function of the left atrium. New insights based on analysis of pressure-volume relations and Doppler echocardiography. Anestesiology (2003) 98:975–994.[CrossRef]
- Nakao F., Wasaki Y., Kimura M., Iwami T., Iida H., Wakeyama T., et al. Evaluation of left atrial function by the functional volume change curve derived from Doppler flow spectra. Jpn Circ J (2001) 65:953–957.[CrossRef][Medline]
- Zhang G., Yasumura Y., Uematsu M., Nakatani S., Nagaya N., Miyatake K., Yamagishi M. Echocardiographic determination of left atrial function and its application for assessment of mitral flow velocity pattern. International Journal of Cardiology (1999) 72:19–25.[CrossRef][Web of Science][Medline]
- Marino P., Faggian G., Bertolini P., Mazzucco A., Little W. Early mitral deceleration and left atrial stiffness. Am J Physiol Heart Circ Physiol (2004) 287:H1172–H1178.
[Abstract/Free Full Text] - Kowalski M., Kukulski T., Jamal F., Dhooge J., Weidemann F., Rademakers F., et al. Can natural strain and strain rate quantify regional myocardial deformation? A study in healthy subjects. Ultrasound Med Biol (2001) 27:1087–1097.[CrossRef][Web of Science][Medline]
- Hatle L., Sutherland G.R. Regional myocardial function – a new approach. Eur Heart J (2000) 21:1337–1357.
[Free Full Text] - D'hooge J., Heimdal A., Jamal F., Kukulski T., Bijnens B., Rademakers F., et al. Regional strain and strain rate measurements by cardiac ultrasound: principles, implementation and limitations. Eur J Echocardiography (2000) 1:154–170.[CrossRef]
- Sutherland G.R., Di Salvo G., Claus P., D'hooge J., Bijnens B. Strain and strain rate imaging: A new clinical approach to quantifying regional myocardial function. J Am Soc Echocardiogr (2004) 17:788–802.[CrossRef][Web of Science][Medline]
- Kukulski T., Hubbert L., Arnold M., Wranne B., Hatle L., Sutherland G.R. Normal regional right ventricular function and its change with age: a Doppler Myocardial Imaging study. J Am Soc Echocardiogr (2000) 13:194–204.[Web of Science][Medline]
- Thomas L., Levett K., Boyd A., Leung D.Y., Schiller N.B., Ross D.L. Changes in regional left atria function with aging: evaluation by Doppler tissue imaging. Eur J Echocardiography (2003) 4:92–100.[CrossRef]
- Lester S.J., Ryan E.W., Schiller N.B., Foster E. Best method in clinical practice and in research studies to determine left atrial size. Am J Cardiol (1999) 84:829–832.[CrossRef][Web of Science][Medline]
- Khankirawatana B., Khankirawatana S., Porter T. How should left atrial size be reported? Compared assessment with use of multiple echocardiographic methods. Am Heart J (2004) 147:369–374.[CrossRef][Web of Science][Medline]
- Gottdiener J.S. Left atrial size: renewed interest in an old echocardiographic measurement. Am Heart J (2004) 147:195–196.[CrossRef][Web of Science][Medline]
- Tirrito S.J., Augustine D.R., Kennet Kerut E. How to measure left atrial volume. Echocardiography (2004) 21:569–571.[CrossRef][Web of Science][Medline]
- Nikitin N.P., Witte K.K., Thackray S.D., Goodge L.J., Clark A.L., Cleland J.G. Effect of age and sex on left atrial morphology and function. Eur J Echocardiography (2003) 4:36–42.[CrossRef]
- Bland J.M., Altman D.G. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet (1986) 1:307–310.[CrossRef][Web of Science][Medline]
- Sun P.J., Popovic Z.B., Greenberg N.L., Xu X.F., Asher C.R., Stewart W.J., et al. Non invasive quantification of regional myocardial function using Doppler derived velocity, displacement, strain rate and strain in healthy volunteers: effects of aging. J Am Soc Echocardiogr (2004) 17:132–138.[CrossRef][Web of Science][Medline]
- Abraham T.P., Nishimura R.A. Myocardial strain: can we finally measure contractility? J Am Coll Cardiol (2001) 37:731–734.
[Free Full Text] - Markides V., Schilling R.J., Ho S.Y., Chow A.W., Davies D.W., Peters N.S. Characterization of left atrial activation in the intact human heart. Circulation (2003) 107:733–739.
[Abstract/Free Full Text] - Appleton C.P., Hatle L.K., Popp R.L. Relation of transmitral flow velocity patterns to left ventricular diastolic function: new insights from a combined hemodynamic and Doppler echocardiographic study. J Am Coll Cardiol (1988) 12:426–440.[Abstract]
- Garcia M.J., Thomas J.D., Klein A.L. New Doppler echocardiographic applications for the study of diastolic function. J Am Coll Cardiol (1998) 32:865–875.
[Abstract/Free Full Text] - Tabata T., Oki T., Iuchi A., Yamada H., Manabe K., Fukuda K., et al. Evaluation of left atrial appendage function by measurement of changes in flow velocity patterns after electrical cardioversion in patients with isolated atrial fibrillation. Am J Cardiol (1997) 79:615–620.[CrossRef][Web of Science][Medline]
- Mattioli A.V., Castelli A., Sternieri S., Mattioli G. Doppler sonographic evaluation of left atrial function after cardioversion of atrial fibrillation. J Ultrasound Med (1999) 18:289–294.[Abstract]
- Harjai K.J., Mobarek S.K., Cheirif J., Boulos L.M., Murgo J.P., Abi-Samra F. Clinical variables affecting recovery of left atrial mechanical function after cardioversion from atrial fibrillation. J Am Coll Cardiol (1997) 30:481–486.[Abstract]
- Mattioli A.V., Sansoni S., Lucchi G.R., Mattioli G. Serial evaluation of left atrial dimension after cardioversion for atrial fibrillation and relation to atrial function. Am J Cardiol (2000) 85:832–836.[CrossRef][Web of Science][Medline]
- Kircher B., Abbott J.A., Pau S., Gould R.G., Himelman R.B., Higgins C.B., et al. Left atrial volume determination by biplane two-dimensional echocardiography: validation by cine computed tomography. Am Heart J (1991) 121:864–871.[CrossRef][Web of Science][Medline]
- Kawai J., Tanabe K., Wang C.L., Tani T., Yagi T., Shiotani H., Morioka S. Comparison of left atrial size by freehand scanning three-dimensional echocardiography and two-dimensional echocardiography. Eur J Echocardiography (2004) 5:18–24.[CrossRef]
- Piotrowski G., Goch A., Wlazlowski R., Gawor Z., Goch J.H. Non-invasive methods of atrial function evaluation in heart diseases. Med Sci Monit (2000) 6:827–839.[Medline]
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  A. D'Andrea, R. Scarafile, L. Riegler, G. Salerno, R. Gravino, R. Cocchia, F. Castaldo, F. Allocca, G. Limongelli, G. Di Salvo, et al. Right atrial size and deformation in patients with dilated cardiomyopathy undergoing cardiac resynchronization therapy Eur J Heart Fail, December 1, 2009; 11(12): 1169 - 1177. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Kiotsekoglou, J. C. Moggridge, B. H. Bijnens, V. Kapetanakis, F. Alpendurada, M. J. Mullen, S. Saha, D. K. Nassiri, J. Camm, G. R. Sutherland, et al. Biventricular and atrial diastolic function assessment using conventional echocardiography and tissue-Doppler imaging in adults with Marfan syndrome Eur J Echocardiogr, December 1, 2009; 10(8): 947 - 955. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. N. Borg, K. A. Pearce, S. G. Williams, and S. G. Ray Left atrial function and deformation in chronic primary mitral regurgitation Eur J Echocardiogr, October 1, 2009; 10(7): 833 - 840. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Caso, R. Ancona, G. Di Salvo, S. Comenale Pinto, M. Macrino, V. Di Palma, A. D'Andrea, A.R. Martiniello, S. Severino, and R. Calabro Atrial reservoir function by strain rate imaging in asymptomatic mitral stenosis: prognostic value at 3 year follow-up Eur J Echocardiogr, August 1, 2009; 10(6): 753 - 759. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S Eshoo, A C Boyd, D L Ross, T H Marwick, and L Thomas Strain rate evaluation of phasic atrial function in hypertension Heart, July 15, 2009; 95(14): 1184 - 1191. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. P. Appleton and S. J. Kovacs The Role of Left Atrial Function in Diastolic Heart Failure Circ Cardiovasc Imaging, January 1, 2009; 2(1): 6 - 9. [Full Text] [PDF]
|
|
|
|
|
|
M. Kurt, J. Wang, G. Torre-Amione, and S. F. Nagueh Left Atrial Function in Diastolic Heart Failure Circ Cardiovasc Imaging, January 1, 2009; 2(1): 10 - 15. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Jarnert, A. Melcher, K. Caidahl, H. Persson, L. Ryden, and M. J. Eriksson Left atrial velocity vector imaging for the detection and quantification of left ventricular diastolic function in type 2 diabetes Eur J Heart Fail, November 1, 2008; 10(11): 1080 - 1087. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Q. Zhang, G. W.-K. Yip, and C.-M. Yu Approaching regional left atrial function by tissue Doppler velocity and strain imaging Europace, November 1, 2008; 10(suppl_3): iii62 - iii69. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. B. Kaya, L. Tokgozoglu, K. Aytemir, U. Kocabas, E. Tulumen, O. S. Deveci, S. Kose, G. Kabakci, N. Nazli, H. Ozkutlu, et al. Atrial myocardial deformation properties are temporarily reduced after cardioversion for atrial fibrillation and correlate well with left atrial appendage function Eur J Echocardiogr, July 1, 2008; 9(4): 472 - 477. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. P. Abraham, V. L. Dimaano, and H.-Y. Liang Role of Tissue Doppler and Strain Echocardiography in Current Clinical Practice Circulation, November 27, 2007; 116(22): 2597 - 2609. [Full Text] [PDF]
|
|
|
|
 |
|
 A. D'Andrea, P. Caso, S. Romano, R. Scarafile, L. Riegler, G. Salerno, G. Limongelli, G. Di Salvo, P. Calabro, L. Del Viscovo, et al. Different effects of cardiac resynchronization therapy on left atrial function in patients with either idiopathic or ischaemic dilated cardiomyopathy: a two-dimensional speckle strain study Eur. Heart J., November 2, 2007; 28(22): 2738 - 2748. [Abstract] [Full Text] [PDF]
|
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|
|
|
|
L. F Tops, E. E van der Wall, M. J Schalij, and J. J Bax Multi-modality imaging to assess left atrial size, anatomy and function Heart, November 1, 2007; 93(11): 1461 - 1470. [Abstract] [Full Text] [PDF]
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