INTRODUCTION — Tissue Doppler echocardiography (TDE) has become an established component of the diagnostic ultrasound examination; it permits an assessment of myocardial motion using Doppler ultrasound imaging. The technique uses frequency shifts of ultrasound waves to calculate myocardial velocity; this is similar to use of routine Doppler ultrasound to assess blood flow, but its technological features focus on lower velocity frequency shifts [1-3]. (See "Principles of Doppler echocardiography".)
This topic will review technical aspects and clinical applications of TDE. Other aspects of echocardiography are discussed separately. (See "Transthoracic echocardiography: Normal cardiac anatomy and tomographic views" and "Echocardiography essentials: Physics and instrumentation".)
TECHNICAL ASPECTS — Two techniques have been used to assess myocardial function: pulsed-TDE and color-coded TDE, which is an extension of the pulsed-Doppler technique.
Tissue Doppler ultrasonography utilizes modifications of blood flow Doppler technology and calculates velocity from frequency shifts in received ultrasound data in a similar manner. Thus, the fundamental units are velocity observed from the echocardiographic transducer as a frame of reference. A primary advantage of TDE is that Doppler shifts of tissue motion are of high amplitude, being approximately 40 dB higher than Doppler signals from blood flow [4,5]. An instrumentation feature common to both pulsed and color-coded TDE involves removal of the high-pass filter used for routine Doppler to assess blood flow in order to focus on the lower velocity values of myocardial motion [4-6]. The principal disadvantage of TDE is the influence of the angle of incidence of the ultrasound beam to the tissue motion, which has a major effect on calculation of velocity data by the Doppler equation.
Pulsed-TDE — Pulsed-TDE is available on all contemporary commercial echocardiography systems. The details of TDE set-up are unique to each system, but TDE is generally executed though a system preset feature. Operation is then very similar to routine pulsed-Doppler, with adjustments of the scale and sweep speed to optimize the spectral display, similar to pulsed-Doppler of blood flow. The gate of the sample volume of pulsed-TDE is usually opened to 1 cm and directed to assess the region of interest that is most commonly the mitral annulus at lateral and medial sites from the apical four-chamber view. For color-TDE, routine color flow instrumentation uses the autocorrelator technique to calculate and display multigated points of color-coded blood velocity along a series of ultrasound scan lines within a two-dimensional sector . Color-coded blood velocity data are then superimposed on conventional gray scale two-dimensional images in real time.
Color-coded TDE — Color-coded tissue velocities can be superimposed on conventional M-mode and two-dimensional images (image 1 and image 2A-B and figure 1). Pulse repetition frequencies can be increased to enhance temporal resolution. As an example, TDE measurements can be made at 40 Hz with a 60 degree two-dimensional sector at approximately 15 cm depth setting and at over 300 Hz using color M-mode scanning with a commercially available ultrasound system.
The operation of color-coded TDE is similar to operation of routine color flow Doppler instrumentation. Variables include:
●Color gain – TDE color gain should be maximized to below the level of color noise artifact.
●Velocity range – Since the most common application of TDE is to interrogate myocardial velocities, a velocity range should be selected to maximize the sensitivity of displaying lower velocity values, without limiting the ability to measure higher velocity values. Velocities that exceed the upper limits of the selected range can be displayed as a saturated value at that highest velocity value in some systems. Selected velocity ranges of ±9 to ±20 cm/s appear to be useful to assess myocardial velocity by TDE.
Advantages and disadvantages of TDE — A major advantage of TDE is its high signal to noise ratio so that measurements such as mitral annular velocity are possible in nearly all consecutive patients. The major disadvantages of myocardial velocity by TDE are its inability to differentiate active contraction from passive motion, such as from regional tethering or scar and angle of incidence that affects Doppler calculations. For these reasons, speckle tracking strain imaging has surpassed TDE for quantitative evaluation of global and regional LV systolic function.
CLINICAL APPLICATIONS — TDE has been applied in several clinical settings, particularly in the assessment of left ventricular (LV) systolic and diastolic function. Pulsed-TDE is the modality most commonly used in current clinical practice. Pulsed-TDE measures of mitral annular velocity have established usefulness for assessment of LV systolic and diastolic function, estimation of LV filling pressures, and in the diagnosis of hypertrophic cardiomyopathy, cardiac amyloidosis, and the athletic heart. Also, TDE determination of LV dyssynchrony has been shown to provide prognostic information for cardiac resynchronization therapy (CRT) patients, but is presently not supported for use in patient selection.
Mitral annular velocity alone or in combination with mitral inflow velocity (E) to estimate LV diastolic function are the most commonly used clinical applications. TDE assessment of mitral annular velocity (e’) has been widely accepted as a component of determining LV diastolic function. TDE also may quantify regional and global LV function through the assessment of myocardial velocity data; however, speckle tracking strain imaging has become the clinical standard, rather than TDE.
Assessment of global and regional left ventricular systolic function — The ability of TDE to assess regional LV function has been previously studied [6,8-10]. One study of 12 patients with heart disease and 20 normal subjects found that, by comparing TDE velocity values with estimates of velocity from digitized routine M-modes scans, TDE was able to measure endocardial velocity; peak velocity, measured by color-coded TDE, correlated closely with peak velocity by digitized M-modes (r = 0.99) (image 1 and image 2A-B and figure 1) . In 16 subjects who could be adequately analyzed, posterior wall endocardial velocities throughout the cardiac cycle on TDE correlated with the velocity estimated from digitized M-modes (r = 0.88).
In a canine model, color-coded TDE objectively quantified a wide range of alterations in regional contractility induced by inotropic modulation . Using myocardial length crystals as a reference standard to assess regional LV function, and high fidelity pressure and conductance catheters to assess global LV performance by pressure-volume relations, mid-ventricular M-mode and two-dimensional color TDE images were recorded during control and inotropic stimulation with dobutamine followed by esmolol.
Dobutamine produced significant increases in peak systolic endocardial velocity, systolic time velocity integral (TVI), and diastolic TVI; after an infusion of esmolol, there were significant decreases in these indices of myocardial contractility. Changes in TDE peak systolic velocity were correlated with changes in fractional shortening (r = 0.88) and shortening velocity (r = 0.87) by sonomicrometry. Changes in TDE peak velocity from multiple mid-LV sites also correlated significantly with maximal elastance obtained from pressure-volume relations (r = 0.85).
Pulsed TDE can also quantify regional LV function as demonstrated in an animal model of ischemia and reperfusion . Peak septal velocities, obtained from pulsed TDE, were calculated during systole, isovolumic relaxation, and early and late diastole; regional myocardial blood flow and systolic and diastolic function were assessed by radioactive microspheres and ultrasonic crystals, respectively. Ischemia, produced by coronary artery occlusion, resulted in a significant rapid reduction of systolic velocities and abnormalities in diastolic function; these changes were detected by pulsed TDE within five seconds of occlusion. The decrease in systolic velocity on pulsed TDE correlated significantly with both systolic shortening (r = 0.90) and regional myocardial blood flow (r = 0.96) during the reduction in coronary blood flow.
Strain and strain rate imaging — Strain imaging has made a major impact on quantifying global and regional LV function. The advance of strain imaging began with TDE strain rate imaging. Strain, which is the ratio of change in length over the original length or the fractional or percentage change from the original or unstressed dimension. Quantification of deformation may therefore may be applied to describe the contraction/relaxation pattern of the myocardium; strain rate is the rate of this deformation and is associated with LV contractility (figure 2) [1,13-16].
Strain rate is the change in strain with respect to time, also known as the first derivative of strain. Strain rate imaging involves mathematical subtraction of the whole heart or translational motion from regional thickening velocity using a transmural data set from color-coded TDE [16-18]. This quantification of the spatial distribution of intramural velocities across the myocardium has improved the ability of TDE to reflect directional and incremental alterations in regional and global LV contractility in patients with cardiovascular disease [16,19]. The technique can also identify regional diastolic abnormalities due to postsystolic shortening during ischemia, thereby defining the extent of ischemic myocardium . When used with low-dose dobutamine, it is also a useful method for assessing the degree of myocardial viability . (See "Evaluation of hibernating myocardium".)
Use during dobutamine stress echocardiography — Dobutamine stress echocardiography is a technique for evaluating regional wall motion abnormalities due to ischemia that is induced by pharmacologic stress; it is useful for the diagnosis of coronary heart disease or determining the viability of dysfunctional myocardium (see "Dobutamine stress echocardiography in the evaluation of hibernating myocardium"). A major limitation of this approach is that diagnostic criteria are based on the somewhat subjective visual assessment of wall motion, with segments scored in a semi-quantitative manner.
Color-coded TDE has the potential to objectively measure myocardial velocity as a means of more accurately assessing regional LV function by echocardiography [22,23]. In one report of 60 patients, the normal and abnormal segmental endocardial velocity response to dobutamine stress was evaluated with color-coded TDE and compared with routine visual inspection of segmental function with two-dimensional gray scale images; echocardiographic images were obtained from the parasternal long and short-axis and apical four and two chamber views . Wall motion abnormalities at peak stress occurred in 19 patients while 22 patients who reached their target heart rate and had normal wall motion at peak stress served as a control group. Segmental peak endocardial velocities by TDE increased significantly in all segments in the control group, while endocardial velocity was significantly lower at peak stress in those who developed abnormal segments motion. In a second study of 114 patients who underwent coronary angiography within two months of dobutamine stress TDE, the sensitivity, specificity, and overall accuracy of TDE was 83, 72, and 80, percent, respectively; these values were equivalent to those obtained with expert wall motion scoring .
TDE strain and strain rate imaging can also be used as an adjunct to visual wall motion analysis to assess myocardial viability. A study of 55 patients applied strain and strain rate imaging to the standard apical four-chamber, two-chamber, and long axis views along with routine visual wall motion scoring during a dobutamine echo viability study . Patients were reassessed nine months after percutaneous revascularization or coronary bypass surgery. Of the 42 percent of patients with improvements in LV function after revascularization, strain and strain rate imaging combined with visual assessment increased sensitivity from 73 to 83 percent, compared with visual assessment alone. Although specificity was unaffected, strain imaging has potential to assist in determining myocardial viability.
Strain and strain rate imaging by TDE have the advantage of high frame rates and preserved temporal resolution. Speckle tracking strain imaging is being developed for applications in stress echocardiography, but frame rates are lower than TDE. A limitation of tissue Doppler strain is that data are derived from relative changes in velocity along a single ultrasound scan line and myofiber orientation is three-dimensionally complex. It may accurately assess shortening or thickening only when this principal vector is aligned with the ultrasound beam, which is affected by the angle of incidence in the Doppler equation. Accordingly, TDE cannot reliably assess apical segments from apical windows or regions where Doppler angle approaches perpendicular. After excluding apical segments from analysis, a TDE-measured peak velocity of <5.5 cm/s with peak stress had an average sensitivity, specificity, and accuracy of 96, 81, and 86 percent, respectively, for identifying abnormal segments at peak stress as defined by routine two-dimensional criteria .
Mitral annular velocity to assess LV function — Mitral annular motion assessed by M-mode echocardiography has historically been used as an index of global LV systolic function . This motion can be easily viewed from the apical windows in most patients (figure 3). Mitral annular descent reflects the longitudinal shortening of the LV chamber and correlates with other global measures of LV function, such as stroke volume [26-28]. Although two-dimensional echocardiography has become the standard to assess LV function and ejection fraction, an advantage of using mitral annular motion to determine LV function is that an adequate endocardial tracing is not necessary . (See "Tests to evaluate left ventricular systolic function".)
TDE, obtained from the apical windows, offers an advantageous ultrasound beam angle of incidence for Doppler calculations, which accordingly have favorable signal-to-noise ratios (figure 3). Mitral annular descent velocity by pulsed-TDE can measure the systolic velocity, or S wave, as a rapidly acquired index of global LV function (figure 3). As an alternative, color-coded TDE may also assess mitral annular velocity [29,30]. In one study of 55 patients, color-coded TDE was compared with radionuclide ventriculography, which served as a standard of reference of LV ejection fraction (LVEF) . TDE color M-mode echocardiograms were obtained from six mitral annular sites, including inferoseptal and lateral images from apical four chamber views, anterior and inferior images from apical two chamber views, and anteroseptal and posterior images from apical long axis views (figure 4). The following findings were noted:
●The mean LVEF, based upon the peak annular descent velocity was 49 percent, which had excellent linear correlation with the ejection fraction obtained from the radionuclide ventriculogram (r = 0.86).
●Peak mitral annular descent velocity average >5.4 cm/s had a sensitivity and specificity of 88 and 97 percent for an ejection fraction greater than 50 percent.
●Peak mitral annular descent velocity from the apical four chamber view correlated most closely with radionuclide ejection fraction.
Mitral annular velocity is also a sensitive indicator of alterations in LV contractility induced by inotropic stimulation using low dose dobutamine. This was illustrated in a report of 12 healthy subjects in which the myocardial response to low dose dobutamine infusion was quantified using a new semiautomated color-coded TDE analysis system . Mitral annular velocity was obtained from the apical four-chamber view using the medial site and the results were compared with routine two-dimensional echocardiography . Mitral annular peak systolic velocity increased significantly at the lowest dose of dobutamine (1 mg/kg per min), with further incremental increases with each increase in dobutamine dose; in contrast, routine measures of LVEF did not detect an increase until the dose of dobutamine was 3 mg/kg per min. These data support the use of mitral annular velocity by TDE as a means of assessing LV function, especially when endocardial definition is suboptimal. Echocardiographic assessment of longitudinal LV motion as an important measure of global function is assessed most often by longitudinal strain imaging and the index of global longitudinal strain (GLS). (See 'Strain and strain rate imaging' above.)
Prognostic utility in heart failure — Mitral annular Ea (also called E’) has important prognostic utility in heart failure patients. In a series of 182 patients with abnormal ejection fraction (<50 percent), a peak systolic velocity (S) <3 cm/s using pulsed tissue Doppler of the mitral annulus was associated with an unfavorable five-year survival rate . The ratio E/e’ >15 was associated with a high mortality rate after acute myocardial infarction in a series of 205 patients , and poor survival in a series of 116 heart failure patients . Additionally, in patients with impaired systolic function, S <3 cm/s was shown to be of incremental prognostic value to clinical risk factors, mitral deceleration time <140ms and E/E’ >15 . In patients with chronic systolic heart failure, global longitudinal strain by speckle tracking echocardiography has been shown to be of incremental prognostic value to clinical factors and E/e’ .
Use in evaluating chronic aortic regurgitation — TDE may be helpful for identifying subclinical LV dysfunction in patients with chronic severe aortic regurgitation who are asymptomatic but may be candidates for surgery (see "Natural history and management of chronic aortic regurgitation in adults"). In one study of 21 asymptomatic patients, reduced long axis contraction, as measured by mitral annular excursion and systolic velocity, were indicators of subclinical LV dysfunction established by impaired exercise capacity and a reduction in ejection fraction with exercise . A systolic annular excursion <12 mm and a resting mitral annular velocity <9.5 cm/s were the best indicators of subclinical LV dysfunction.
Use in heart failure and resynchronization therapy — TDE measures of the severity of LV intraventricular dyssynchrony may provide prognostic information to patients with heart failure who typically have a delay in electrical activation, such as left bundle branch block (LBBB) [37-41]. TDE may also play a role for evaluating the effect of CRT or biventricular pacing on LV function and reverse remodeling. However, guidelines do not advocate using TDE measures of dyssynchrony for patient selection for CRT [37,38]. (See "Cardiac resynchronization therapy in heart failure: Indications and choice of system".)
Color-coded TDE may quantify the degree of LV regional mechanical delay, which is a prognostic marker of response to CRT. The opposing wall delay may be determined as the difference in the TDE time-to-peak systolic velocity, measured during the ejection interval. A peak-to-peak opposing wall delay ≥65 ms has been associated with acute hemodynamic improvement, clinical response, and reverse remodeling following CRT [37,39]. A slightly longer baseline opposing wall delay of ≥80 ms has been associated with long-term survival after CRT . Initially described using the basal segments from the four-chamber view, a 12-segment model using basal and mid segments from apical four-chamber, two-chamber, and apical long axis views is often used for a more complete assessment (waveform 1). The standard deviation of time-to-peak systolic velocity from these same 12 segments, known as the Yu Index (or mechanical dyssynchrony index), ≥33 ms is also associated with clinical outcome and reverse remodeling following CRT [38,42]. These earlier means to predict response to CRT have been replaced by speckle tracking strain measures, such as the systolic stretch index, which appear to be more reliable .
Studies have shown that differences in timing of regional cardiac function may produce peak-to-peak dyssynchrony from contractile heterogeneity or scar, in addition to electrical activation delay . Accordingly, peak-to-peak regional delays assessed by tissue Doppler may not always represent electrical delay, which is an indicator of response to CRT. A useful marker of CRT response is septal contraction before aortic valve opening, known as septal flash. Septal flash is the result of electrical delay associated with systolic pre-stretch, and its presence before CRT and resolution after CRT is a marker for CRT response . Although other reasons for nonresponse to CRT exist, such as LV scar that will not reverse remodel or suboptimal lead placement , the use of tissue Doppler septal flash or speckle tracking strain as a means to identify dyssynchrony resulting from electrical delay may potentially be used to predict response to CRT for prognostic purposes . (See 'Comparison with speckle tracking' below.)
CRT guidelines most strongly favor a widened electrocardiographic QRS ≥150 ms with an LBBB morphology as a marker for the most favorable response and echo-Doppler methods have not been established for patient selection for CRT. The systolic stretch index has promise for adding to ECG criteria for CRT in heart failure patients with intermediate ECG criteria QRS 120 to 149 ms or non-LBBB . (See "Cardiac resynchronization therapy in heart failure: Indications and choice of system".)
Assessment of diastolic function — The peak negative myocardial velocity can provide a quantitative assessment of diastolic dysfunction. In one study of 43 patients with and without impaired LV systolic and diastolic function, peak negative myocardial velocity was significantly depressed in those with diastolic dysfunction due to hypertensive heart disease or a dilated cardiomyopathy compared with normals (waveform 2) . Compared with transmitral flow velocity, myocardial velocity gradient (MVG), which is defined as the slope of the regression line for the transmural velocity profile between the endocardium and epicardium cross the myocardial wall and reflects myocardial thickening and thinning dynamics, was less affected by changes in preload produced by leg raising or diuretic therapy. (See "Echocardiographic evaluation of left ventricular diastolic function in adults", section on 'Tissue Doppler imaging'.)
Use of mitral annular velocity — The longitudinal expansion of the LV during early diastole, as assessed by mitral annular velocity, is an interesting and useful application of TDE [46-48]. One study used the early diastolic mitral annular velocity (e’ also known as Ea), obtained by pulsed-TDE in 128 patients undergoing cardiac catheterization; the magnitude of e’ (in cm/s) was blunted in patients with diastolic dysfunction, established by other means, such as the time constant of relaxation by high-fidelity pressure catheters . The e’ appeared to be less influenced by alterations of loading, such as an increased volume with a saline infusion or preload reduction by nitroglycerin, than mitral inflow velocity. However, the load-independence of e’ is still uncertain and this is undergoing more careful study.
Despite this limitation, there are several important clinical applications of e’. These include an assessment of LV filling pressures, differentiating constrictive pericarditis from restrictive cardiomyopathy, and differentiating hypertrophic cardiomyopathy from LV hypertrophy as discussed below.
Estimation of LV filling pressures — Determination of LV filling pressure is important for the optimization of LV function in patients with cardiovascular disease. Since this usually requires the invasive placement of a pulmonary artery catheter, a noninvasive estimation of LV filling pressures would be clinically useful. TDE is a possible solution, particularly in patients with a reduced LVEF. However, the reliability of transmitral flow variables is reduced in patients with an LVEF ≥50 percent. A review of technical issues in such patients with a systematic approach for the ultrasonographer was published in early 2005 .
It has been proposed that the mitral inflow to annular velocity ratio is a possible application of TDE to noninvasively assess LV filling pressures (image 3) [47,50,51]. This approach uses measures of transmitral peak inflow velocity of early rapid diastolic filling (E), obtained by routine pulsed-Doppler echocardiography, and measures of e’, obtained by pulsed-TDE sample volume placed in the lateral annulus imaged from the apical four chamber view. The unitless index of E/e’, used as an indicator of LV filling pressures, correlated significantly with invasively derived mean pulmonary capillary wedge pressure (r = 0.87) and showed better correlation with LV end-diastolic pressure (a measure of LV filling pressure) than did other Doppler variables [47,50].
E/Ea estimates of filling pressures can be made in patients with arrhythmias, such as sinus tachycardia, and also in patients with heart failure. As a general clinical guideline, an E/e’ >10 is predictive of a mean pulmonary capillary wedge pressure above 15 mmHg with a sensitivity and specificity of 92 and 80 percent, respectively.
Use of LV early diastolic strain and left atrial strain — There are several studies showing a significant association of LV relaxation with LV diastolic strain rate during the isovolumic relaxation period and during early diastole (acquired by speckle tracking) [52,53]. Likewise, the ratio of mitral E velocity to both measurements has significant correlations with LV filling pressures [52-55]. While there is less evidence for their association with cardiovascular outcomes in comparison with E/e’ ratio, the existing data suggest incremental prognostic power over clinical and other echocardiographic measurements of LV structure and function [56-58].
Left atrial (LA) reservoir strain measured by speckle tracking is inversely related with LV filling pressures, with a stronger correlation in patients with reduced LVEF than that seen in patients with normal LVEF [59,60]. There are data showing the association of reduced LA reservoir strain with the development of heart failure .
LA reservoir strain is associated with likelihood of successful cardioversion in patients with atrial fibrillation, as well as the subsequent recurrence of atrial fibrillation after cardioversion [61,62].
Differentiation of constrictive pericarditis from restrictive cardiomyopathy — The differentiation between suspected constrictive pericarditis or restrictive cardiomyopathy is often difficult and the invasive evaluation may yield ambiguous data. (See "Differentiating constrictive pericarditis and restrictive cardiomyopathy".)
Distinction between these two entities is of great importance because constrictive pericarditis may be cured with surgical pericardiectomy and is often lethal without intervention. Restrictive cardiomyopathy, such as with advanced amyloid heart disease, is usually associated with a poor prognosis but has expanding treatment options. (See "Restrictive cardiomyopathies" and "Cardiac amyloidosis: Treatment and prognosis" and "Cardiac amyloidosis: Epidemiology, clinical manifestations, and diagnosis".)
A Doppler echocardiographic assessment of mitral inflow velocities, pulmonary venous velocities, and hepatic vein flow patterns can be used to make this distinction; however, their value is limited in some patients. (See "Differentiating constrictive pericarditis and restrictive cardiomyopathy".)
TDE assessment of e’ is an important noninvasive measure that can be combined with the routine Doppler echocardiogram and provides complementary information. Ea obtained by pulsed-TDE is useful to distinguish patients with constrictive pericarditis from seven patients with restrictive cardiomyopathy . Since restrictive cardiomyopathy is a disease of the myocardium, e’ is reduced, usually <6.0 cm/s, whereas constrictive pericarditis is a disease of the pericardium and e’ velocity is preserved or elevated >10 cm/s.
General guidelines are that an e’ less than 8 cm/s by pulsed-TDE and less than 7 cm/s by color-coded TDE are supportive of restrictive pathophysiology (figure 5) . Measurement of early mitral annular velocity (e', also called Ea) more be more helpful. In a series of 75 patients, an e' of more than 8 cm/s had a 95 percent sensitivity and 96 percent specificity for the diagnosis of constrictive pericarditis (image 4) .
Pulsed-TDE can also distinguish between restrictive cardiomyopathy and constrictive pericarditis by measuring the myocardial velocity gradient . The Doppler myocardial velocity gradient, as measured from the LV posterior wall in early diastole and during ventricular ejection, was significantly lower in patients with a restrictive cardiomyopathy compared with those with constrictive pericarditis and normal controls (figure 6 and figure 7 and waveform 3).
Differentiation of hypertrophic cardiomyopathy from left ventricular hypertrophy and the athletic heart — Although the echocardiographic findings of systolic anterior movement of the mitral valve, dynamic LV outflow tract gradients, and asymmetrical septal hypertrophy are useful for diagnosing hypertrophic cardiomyopathy, these findings may also be present in patients with LV hypertrophy secondary to hypertension or vigorous exercise. TDE mitral annular velocity is particularly useful in the clinical assessment of the athletic heart. Mitral annular velocities are often high in athletes, especially those who are endurance trained, and reduced in those with hypertrophic cardiomyopathy . TDE is useful in distinguishing among these disorders, as discussed separately. (See "Echocardiographic recognition of cardiomyopathies" and "Hypertrophic cardiomyopathy: Clinical manifestations, diagnosis, and evaluation", section on 'Criteria to distinguish HCM from athlete's heart'.)
COMPARISON WITH SPECKLE TRACKING — A speckle is a unique acoustic pattern generated from ultrasound interrogation of tissue. Speckle tracking is a semiautomated means of measuring myocardial strain and strain rate . This method can detect longitudinal, circumferential, or radial displacement, although radial measurements require adequate image quality . Advantages of speckle tracking over TDE include lack of dependence upon the angle of the incident ultrasound beam and lack of requirement for specialized imaging since speckle analysis is performed on routine B-mode images . Disadvantages include significant signal noise and signal drifting as well as lower frame rates (40 to 90 frames/s as compared with >100 frames/s for TDE) [70,71]. Data supporting the utility of speckle tracking imaging for clinical applications continue to expand. (See "Echocardiographic evaluation of left ventricular diastolic function in adults".)
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SUMMARY — Tissue Doppler echocardiography (TDE) is a rapidly evolving and expanding noninvasive technique to assess left ventricular (LV) physiology. Further refinements in signal processing and quantitative analysis will likely expand the clinical applications of this technique.
●Clinical applications of TDE include the following:
•Evaluation of global and regional LV systolic function at rest and with dobutamine stress. (See 'Assessment of global and regional left ventricular systolic function' above.)
•Evaluation of LV diastolic function including estimation of LV filling pressures. (See 'Assessment of diastolic function' above.)
●Specific applications of TDE in distinguishing clinical entities include the following:
•Prognosis in heart failure using mitral annular systolic velocity (E’ or Ea) in addition to mitral inflow to annular ratio (E/E’). (See 'Prognostic utility in heart failure' above.)
•Differentiation of constrictive pericarditis from restrictive cardiomyopathy. (See 'Differentiation of constrictive pericarditis from restrictive cardiomyopathy' above.)
•Differentiation of hypertrophic cardiomyopathy from LV hypertrophy secondary to exercise. (See 'Differentiation of hypertrophic cardiomyopathy from left ventricular hypertrophy and the athletic heart' above.)
●Speckle tracking offers an alternative means of measuring myocardial strain and strain rate. The relative clinical utilities of speckle tracking and TDE are not well defined.
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