Peak negative myocardial velocity gradient in early diastole as a noninvasive indicator of left ventricular diastolic function: Comparison with transmitral flow velocity indices

Objectives. We sought to assess the clinical significance of peak negative myocardial velocity gradient (MVG) in early diastole as a noninvasive indicator of left ventricular (LV) diastolic function.Background. Peak systolic MVG has been shown useful for the quantitative assessment of regional wall motion abnormalities, but limited data exist regarding the diastolic MVG as an indicator of LV diastolic function.Methods. Peak negative MVG was obtained from M-mode tissue Doppler imaging (TDI) in 43 subjects with or without impairment of systolic and diastolic performance: 12 normal subjects, 12 patients with hypertensive heart disease (HHD) with normal systolic performance and 19 patients with dilated cardiomyopathy (DCM), and was compared with standard Doppler transmitral flow velocity indices. In a subgroup of 30 patients, effects of preload increase on these indices were assessed by performing passive leg lifting. In an additional 11 patients with congestive heart failure at the initial examination, the measurements were repeated after 26 ± 16 days of volume-reducing therapy.Results. Peak negative MVG was significantly depressed both in HHD (−3.9 ± 1.3/s, p < 0.01 vs. normal = −7.7 ± 1.5/s) and DCM (−4.4 ± 1.4/s, p < 0.01 vs. normal). In contrast, transmitral flow indices failed to distinguish DCM from normal due to the pseudonormalization. Transmitral flow velocity indices were significantly altered (peak early/late diastolic filling velocity [E/A] = 1.1 ± 0.5 to 1.5 ± 0.7, p < 0.01; E deceleration time = 181 ± 41 to 153 ± 38 ms, p < 0.01), while peak negative MVG remained unchanged (−5.3 ± 2.2 to −5.3 ± 2.0/s, NS) by leg lifting. Volume-reducing therapy resulted in the apparent worsening of the transmitral flow velocity pattern toward abnormal relaxation, as opposed to peak negative MVG, which improved by the therapy (p < 0.05).Conclusions. Peak negative MVG derived from TDI may be a noninvasive indicator of LV diastolic function that is less affected by preload alterations than the transmitral flow velocity indices, and thereby could be used for the follow-up of patients with nonischemic LV dysfunction presenting congestive heart failure.     

Novel approach to the quantitation of regional left ventricular systolic and diastolic function using tissue Doppler imaging to create a myocardial velocity profile and gradient.

The myocardial velocity profile (MVP) and gradient (MVG) between the endocardium and epicardium of the left ventricular (LV) wall measured by color-coded tissue Doppler imaging (TDI) are new indices for evaluating regional LV myocardial function. However, accurate recording and measurement of the MVP is difficult using conventional methodology because of the stochastic nature of the ultrasound signal; that is, the effect of speckled noise. The aim of this study was to validate the accuracy and establish the validity of a newly developed method for measuring the MVP and MVG using 10 clinically normal controls and 10 patients with a hypertensive hypertrophied LV posterior wall. A non-isotropic, averaging algorithm was developed that was capable of obtaining a stable MVP (averaged MVP). Averaged MVP was recorded using parasternal, LV short-axis, color-coded TDI, placing regions of interest along the LV posterior wall with the reference point for angle-correction being at the center of LV contraction. The velocity from epicardium to endocardium within the region of interest was automatically angle-corrected to calculate the velocity component radially relative to the LV cavity and was spatially averaged along the circumference within the region of interest. Inter- and intraobserber variabilities of measurements were lower in the averaged MVP and MVG than in the conventional MVP and MVG. The correlation coefficients of the linear regression lines of systolic and early diastolic MVPs in the LV posterior wall were higher in all controls and hypertensive patients with the averaged method than with the conventional TDI procedures. The mean peak systolic and early diastolic MVGs were lower in the hypertensive group than in the controls. In conclusion, the newly developed averaged MVP provides a stable and reproducible index for the quantitative assessment of regional LV myocardial function.     

Potential application of tissue Doppler imaging to assess regional left ventricular diastolic function in patients with hypertrophic cardiomyopathy: comparison with 123I-beta-methyl iodophenyl pentadecanoic acid myocardial scintigraphy

BACKGROUND: Tissue Doppler imaging (TDI) has been utilized to evaluate left ventricular myocardial dysfunction in patients with hypertrophic cardiomyopathy (HCM); however, no clear explanation for the abnormality of TDI variables has been forthcoming. HYPOTHESIS: Peak negative myocardial velocity gradient (MVG) derived from TDI may correlate with a disorder of fatty acid metabolism in patients with HCM. METHODS: Tissue Doppler imaging and 123I-beta-methyl iodophenyl pentadecanoic acid (123I-BMIPP) myocardial scintigraphy were performed in 15 patients with asymmetric septal hypertrophy (mean age 47 +/- 18 years) and in 12 healthy controls (mean age 43 +/- 10 years). RESULTS: In early 123I-BMIPP images, accumulation defects were observed in the ventricular septum in 12 patients and in the posterior wall in 8 patients with HCM. Peak negative MVG in the ventricular septum (1.1 +/- 0.5 vs. 2.8 +/- 0.5, p < 0.0001) and posterior wall (5.2 +/- 1.4 vs. 6.7 +/- 0.8, p < 0.01 ) was significantly lower in the HCM group than in the controls; also, these parameters were significantly lower in patients with than in those without a defect in the region in question. The peak negative MVG in the ventricular septum and posterior wall correlated inversely with the washout rate in all subjects. CONCLUSIONS: Peak negative MVG according to TDI is related to disorder of fatty acid metabolism in the regional left ventricular myocardium of patients with HCM.     

Usefulness of the subendocardial myocardial velocity gradient in low-dose dobutamine stress echocardiography

The subendocardial side of myocardium makes a major contribution to left ventricular (LV) contraction and is very susceptible to ischemia. In this study we sought to quantify regional wall motion during low-dose dobutamine stress echocardiography (DSE) by using the myocardial velocity gradient (MVG) derived from tissue Doppler imaging (TDI). We then compared the usefulness of subendocardial MVG with that of transmural MVG in detecting subtle wall motion abnormalities. Fourteen patients (single vessel disease = 6; normal coronary arteries = 8) underwent low-dose DSE (10 μg/kg per min). M-Mode TDI of the LV posterior wall was recorded using a Toshiba SSA-380A combined with custom computer software, and analyzed for both subendocardial and transmural MVG. Visual estimation and transmural MVG failed to clearly demonstrate the differing responses between the nonischemic (systole: 3.0 ± 0.8/s to 4.9 ± 1.9/s, not significant; diastole: −4.3 ± 1.3/s to −5.7 ± 1.4/s, not significant; mean ± SD, P versus ischemic segments) and ischemic (systole: 3.3 ± 1.2/s to 3.8 ± 1.0/s; diastole: −5.4 ± 2.0/s to −5.3 ± 1.1/s) segments during low-dose DSE. Subendocardial MVG demonstrated a significant change in the nonischemic segments (systole: 4.1 ± 1.0/s to 7.7 ± 2.2/s, P = 0.012; diastole: −6.5 ± 1.8/s to −11.3 ± 2.2/s, P = 0.001), whereas the response remained unchanged in the ischemic segments (systole: 4.6 ± 2.4/s to 4.8 ± 1.2/s; diastole: −7.0 ± 1.9/s to −7.3 ± 1.1/s). Subendocardial MVG, particularly diastolic subendocardial MVG, may serve as a useful indicator of subtle ischemic changes in wall motion induced by low-dose DSE. Received: December 10, 1999 / Accepted: April 28, 2000     

Losartan improves regional left ventricular systolic and diastolic function in patients with hypertension: accurate evaluation using a newly developed color-coded tissue doppler imaging technique

BACKGROUND: Angiotensin II receptor antagonists have recently been accepted as antihypertensive therapy. Tissue Doppler imaging (TDI) has been developed as a noninvasive tool to assess quantitatively regional myocardial motion abnormalities. This study was designed to determine whether our newly developed technique of color-coded TDI may be a useful means of quantifying the improvement in regional left ventricular (LV) myocardial contractility and relaxation after treatment with losartan in patients with hypertension. METHODS AND RESULTS: Losartan (50 to 100 mg) was administered for 6 months to 37 previously untreated patients with essential hypertension. Averaged myocardial velocity profiles (MVPs) for color-coded TDI were recorded in the ventricular septum and LV posterior wall before and after treatment. Peak myocardial velocities and peak myocardial velocity gradients (MVGs) in the LV walls were determined during systole and early diastole. The plasma concentration of transforming growth factor (TGF)-beta1 also was measured in all patients. Blood pressure and plasma TGF-beta1 level decreased after initiation of losartan therapy. The LV mass index and LV meridional end-systolic wall stress also decreased after treatment with losartan. LV geometry changed from a pattern consistent with concentric hypertrophy to normal geometry in 10 patients and to a pattern consistent with concentric remodeling in 5 patients, and from concentric remodeling to normal geometry in 5 patients after treatment with losartan. The ratio of early to late diastolic filling for the transmitral flow velocity increased after losartan treatment. The peak systolic and early diastolic myocardial velocities and MVGs in the ventricular septum and LV posterior wall increased after treatment with losartan, although the values 6 months after treatment with losartan were still lower than those in normal individuals. There were good correlations between changes in plasma TGF-beta1 level and changes in systolic and early diastolic MVGs 6 months after losartan. However, there were no significant correlations between changes in the systolic blood pressure and LV end-systolic wall stress and changes in the TDI parameters. CONCLUSION: Losartan improves regional LV function in patients with hypertension. Our newly developed averaged MVP and MVG measurements may be useful for accurately evaluating regional LV myocardial contractility and relaxation in these patients.     

Speckle tracking for assessment of cardiac motion and dyssynchrony

Dyssynchrony estimation using echocardiography is increasingly used as a quantitative tool to qualify candidates for cardiac resynchronization therapy (CRT) and evaluate its effect post procedure. Conventionally, tissue Doppler imaging (TDI) has been used for this application, but its utility and accuracy are limited by the angle of incidence-dependent nature of Doppler velocity measurement. Recently, speckle tracking technology applied to B-mode images has been developed for wall motion analysis including dyssynchrony estimation. Regional motion is tracked by observing the movement of two-dimensional (2D) speckle patterns in ultrasound images. Three-dimensional (3D) speckle tracking is also possible and can be used to evaluate 3D cardiac motion of the entire left ventricle. Speckle tracking can provide assessment of regional strain and dyssynchrony in cardiac motion for more objective diagnosis.     

组织多普勒技术评价扩张型心肌病左室心功能的临床价值

目的探讨组织多普勒技术(TDI)检测扩张型心肌病(DCM)左室心功能的临床价值。方法选择DCM病人和正常健康者各40例,用TDI于胸骨旁长轴检测室间隔及左室后壁中间段短轴方向心肌运动速度(MV),并计算心肌运动速度阶差(MVG);经心尖窗检测左室前壁、后壁、下壁、侧壁和前壁、后壁室间隔中间段长轴方向MV。结果DCM组病人出现4种MV频谱形态异常,长轴、短轴方向MV均明显低于正常对照组(P<0.05或P<0.01);DCM组MVG也明显低于正常对照组(P<0.05或P<0.01)。结论TDI可定量评价DCM病人左室心肌功能,丰富了DCM的超声诊断手段。     

Tissue Doppler imaging detects early asymptomatic myocardial abnormalities in a dog model of Duchenne's cardiomyopathy.

AIMS: Early diagnosis of Duchenne's dilated cardiomyopathy remains a challenge for conventional echocardiography. We sought to determine whether tissue Doppler imaging (TDI) could detect early alteration in myocardial function in a dog model of Duchenne muscular dystrophy, i.e. the Golden Retriever Muscular Dystrophy (GRMD). METHODS AND RESULTS: Myocardial function was assessed by TDI in 20 dogs with normal conventional parameters of systolic function (eight controls and 12 GRMD, 25+/-11 weeks) without knowledge of the genotype. M-mode TDI was recorded from a short-axis view for measurement of endocardial and epicardial velocities and myocardial velocity gradient (MVG) within the posterior wall. Controls and GRMD dogs were comparable regarding left ventricular fractional shortening (37+/-2 vs 42+/-3%, p=ns). Conversely, TDI showed, in all GRMD dogs, a dramatic decrease in systolic MVG (0.8+/-0.1 vs 2.9+/-0.3 s(-1), p<0.0001) and early diastolic MVG (2.3+/-2.2 vs 10.8+/-1.1 s(-1), p<0.0001). This MVG alteration was related to a significant decrease in endocardial velocities in GRMD whereas epicardial velocities were comparable in the two groups. CONCLUSION: These results show that TDI is more sensitive than conventional echocardiography in detecting pre-clinical myocardial abnormalities before occurrence of left ventricular dilation and dysfunction. TDI should be part of the screening techniques for the early diagnosis of cardiomyopathy.     

多普勒组织成像检测冠心病患者梗死心肌的研究

目的　测算比较正常室壁心肌和梗死心肌的运动速度 ,评估多普勒组织成像 (DTI)对冠心病梗死心肌的诊断价值。方法　心肌梗死患者 4 6例 ,分成前壁梗死组 2 9例和下壁梗死组 17例 ,健康人 4 8例作对照 ;在心尖左室长轴切面 (alax)上测得室壁节段厚度 ;于心尖四腔心切面(ap4cv)、心尖二腔心切面 (ap2cv)、胸骨旁左室长轴切面(pslax)和alax应用DTI ,按左室壁 16节段 ,测量各室壁节段心肌运动曲线的速度指标 :收缩期峰值运动速度 (Sm) ;舒张早期峰值运动速度 (Em) :收缩期峰值速度梯度 (PVGs) :舒张早期峰值速度梯度 (PVGe) :收缩期跨壁速度梯度 (MVGs) :舒张早期跨壁速度梯度 (MVGe) ,并分别作组间和组内比较。结果　 (1)心梗患者内膜下心肌绝大多数节段性的室壁运动速度降低 ,与对照组存在显著差异 (P <0 0 1或 <0 0 5 ) :(2 )前壁梗死患者前间隔峰值速度梯度 (PVG)与跨壁速度梯度、(MVG)降低 ,中间段明显降低 (P <0 0 1或 <0 0 5 ) ,后壁基底段的MVGs 显著升高 (P <0 0 5 ) ;前间隔PVG、MVG明显小于后壁 (P <0 0或 <0 0 5 ) ;(3)下壁梗死患者各室壁节段舒张早期峰值速度梯度 (PVGe)除后壁基底段外均降低 ;同水平节段内膜下心肌峰值运动速度 (Sm、Em)趋于一致。结论　梗死心肌运动速度明显低于正常     

Dobutamine stress echocardiography at 7.5 mg/kg/min using color tissue Doppler imaging M-mode safely predicts reversible dysfunction early after reperfusion in patients with acute myocardial infarction

Dobutamine stress echocardiography (DSE) is widely used to predict reversible left ventricular dysfunction, but evaluation by this method is subjective. The recently developed color tissue Doppler imaging (TDI) M-mode may permit objective and quantitative assessment of changes in wall motion induced by DSE. We tested the hypothesis that this new method can detect sensitively reversible dysfunction in the post-myocardial infarction setting. DSE with color TDI M-mode and conventional DSE were performed to predict reversible dysfunction in 53 patients at a mean of 3 days after infarction using 7.5 and 10 microg/kg/min of dobutamine. Follow-up regular echocardiography (4 weeks later) was used as the reference technique to define reversible dysfunction segments. To predict reversible dysfunction segments, the standard segmental wall motion score change on conventional DSE and the ratio of the segmental wall velocity difference at rest versus stress (7.5 and 10 microg/kg/ min) on DSE with color TDI M-mode (7.5-TDI-M and 10-TDI-M, respectively) were used. With 7.5 microg/kg/min of dobutamine, the sensitivity for predicting reversible dysfunction using color TDI M-mode (7.5-TDI-M) was significantly higher than that of conventional DSE (89% vs 73%, p <0.05) whereas specificities and predictive values were almost identical. With a 10-microg/kg/min dose, color TDI-M mode (10-TDI-M) and conventional DSE were not significantly different in predicting reversible dysfunction. With use of color TDI-M mode, regional wall motion during DSE was analyzed objectively and quantitatively. Moreover, combined TDI-M and conventional data were slightly superior to either mode alone. There were no arrhythmias during 7.5 microg/kg/min of dobutamine, but 9 arrhythmias occurred during the 10-microg/kg/min dose in patients with acute myocardial infarction. In conclusion, color TDI M-mode permits objective and quantitative assessment of regional ventricular wall motion and gives additional information for detecting reversible dysfunction in DSE. Improvement of sensitivity at a lower dose of dobutamine with color TDI-M mode may increase the safety of DSE in the post-myocardial infarction setting.     

Detection of left ventricular regional relaxation abnormalities and asynchrony in patients with hypertrophic cardiomyopathy with the use of tissue Doppler imaging

BACKGROUND: It is well known that the distribution and magnitude of left ventricular (LV) hypertrophy are not uniform in patients with hypertrophic cardiomyopathy (HCM), which results in regional heterogeneity of LV early diastolic function. The advent of tissue Doppler imaging (TDI) has allowed the noninvasive evaluation of regional LV wall motion velocities. The aim of this study was to evaluate regional LV relaxation abnormalities and asynchrony noninvasively in patients with HCM by using pulsed and color-coded TDI. METHODS AND RESULTS: We studied 20 patients with asymmetric septal hypertrophy (HCM group) and 18 age-matched normal patients (control group). The peak early diastolic motion velocity (Ew) and time from the aortic component of the second heart sound to the peak of the Ew (II(A)-Ew) were measured by pulsed TDI. The myocardial velocity gradient during early diastole (MVG-Ew) also was measured by color-coded TDI. Mean values for these parameters were determined on the basis of measurements made at 2 sites of the ventricular septum or posterior wall at the levels of chordae tendineae and papillary muscles. The mean Ew and mean MVG-Ew for the ventricular septum and posterior wall were significantly lower, and mean II(A)-Ew was significantly prolonged in the HCM group compared with the control group. This difference was most pronounced in the hypertrophied ventricular septum of the HCM group. The standard deviations of II(A)-Ew for the ventricular septum and posterior wall were significantly greater in the HCM group than in the control group. The time constant of LV pressure decay during isovolumic diastole (tau) correlated inversely with Ew and MVG-Ew and correlated directly with II(A)-Ew. Furthermore, tau correlated directly with the standard deviation of the II(A)-Ew. CONCLUSIONS: LV early diastolic function in patients with HCM may be mediated by an augmentation of regional LV relaxation abnormalities and asynchrony.     

Application of tissue Doppler imaging in cardiology

Tissue Doppler imaging (TDI) is a new echocardiographic technique employing the Doppler principle to measure the velocity of myocardial segments and other cardiac structures. It is well suited for the measurement of long-axis ventricular function. Impairment of longitudinal myocardial fiber motion is a sensitive marker of early myocardial dysfunction and ischaemia, and TDI might therefore become an important tool in routine echocardiography. The technique allows truly quantitative measurement of regional myocardial function both at rest and during stress echocardiography. TDI has great potential in the diagnosis of diastolic left ventricular dysfunction, overcoming the load-dependence of conventional Doppler techniques. Right ventricular function, intracardiac and pulmonary artery pressures, transplant rejection and intraventricular dyssynchrony can also be assessed. This article reviews the current and evolving applications of TDI in cardiology.     

Assessment of the temporal relationship between left ventricular relaxation and filling during early diastole using pulsed Doppler echocardiography and tissue Doppler imaging

The study investigated the temporal relationship between left ventricular (LV) relaxation and filling during early diastole. The transmitral flow (TMF) velocity by pulsed Doppler echocardiography and LV wall motion velocity by pulsed tissue Doppler imaging (TDI) were evaluated in 57 patients with various heart diseases and 33 normal controls. The patients were classified into 2 groups according to the ratio of the peak early diastolic to atrial systolic TMF velocity (E/A): (1) the high A group included 44 patients with an E/A < or = 1, and (2) the pseudonormalization group included 13 patients with an E/A > 1. The isovolumic relaxation time (IRT) from the aortic component of the second heart sound (IIA) to the onset of the E wave of the TMF was measured. The peak early diastolic velocity of the LV posterior wall (Ew) and time from the IIA to the onset of the early diastolic wave (IIA-Ewo) were determined from the LV wall motion velocity assessed by pulsed TDI. The Ew was lower in the pseudonormalization and high A groups than in the control group. The IIA-Ewo was significantly longer in the pseudonormalization and high A groups than in the control group. The time constant of the LV pressure decay at isovolumic diastole (tau) correlated negatively with the Ew, and correlated positively with the IIA-Ewo in all groups. The IIA-Ewo was equal to or shorter than the IRT in control subjects, and was longer than the IRT in patients in the pseudonormalization group. In conclusion, the temporal relationship between LV relaxation and filling during early diastole varied according to the subjects' hemodynamic status. Analysis of TMF by pulsed Doppler echocardiography and LV wall motion velocity by pulsed TDI was useful for detailed evaluation of early diastolic LV hemodynamics.     

Resting Myocardial Velocity Gradient Is a Reliable Measurement That Identifies Viable Myocardium

In the setting of coronary artery disease, two-thirds of LV dysfunction is not the result of irreversible scar, but rather caused by impairment in function and energy use of "still-viable" myocyte. The opportunity for improved function, if coronary blood flow is restored, is there which makes the identification of viable myocardium important. Purpose: The purpose of this study is to identify the value of resting myocardial velocity gradient (MVG) in detecting viable myocardium in patients with healed anterior wall myocardial infarction (MI). Patients and methods: The study included 30 patients with healed anterior MI, who were submitted to conventional echocardiography and tissue Doppler for measurement of MVG. Myocardial perfusion scan using Technetium (Tc)-99m was the gold standard test for the detection of viability. Ten healthy control subjects were also included to obtain reference values for MVG. Results: Resting MVG was able to differentiate infarct regions, and to detect viable myocardium compared to Tc-99m studies (0.68 ± 0.2 vs 0.49 ± 0.22) P < 0.01. Conclusion: MVG provides quantitative assessment of the regional wall thickening that help localizing the infarct zone and detecting viable myocardium at rest.     

Detection of a pseudonormal mitral inflow pattern: an echocardiographic and tissue Doppler study

OBJECTIVE: The aim of this study was to assess the ability of several echocardiographic and tissue Doppler imaging (TDI) derived parameters to improve the noninvasive diagnosis of a pseudonormal mitral inflow pattern. METHODS: Ninety-eight consecutive patients with age-related normal transmitral Doppler profile underwent echocardiography including TDI and measurement of left ventricular end-diastolic pressure (LVEDP) using fluid-filled catheters. Peak transmitral velocities were determined at rest (E, A) and during the strain phase of a Valsalva maneuver. The difference in duration between the pulmonary venous retrograde velocity and the transmitral A-velocity (PVR-A) was calculated from pulsed Doppler recordings. Propagation velocity of the early mitral inflow (VP) was determined by color M-mode. Early diastolic peak mitral annulus velocities (E') and the early diastolic transmyocardial velocity gradient of the posterior basal wall (MVG) were obtained by TDI. RESULTS: Fifty-two patients presented with normal diastolic function (group I: LVEDP9.5 +/- 3 mm Hg, E/A1.1 +/- 0.19), while pseudonormalization, defined as LVEDP 15 mm Hg and E/A > 0.9, was found in 46 patients (group II: LVEDP23 +/- 7 mm Hg, E/A1.43 +/- 0.83). The coefficient of linear correlation (r) and the area under ROC - curve (AUC) to predict LVEDP values 15 mm Hg were maximal for the index PVR-A (AUC = 0.92, r = 0.77), followed byE/E' (AUC = 0.80, r = 0.46), MVG (AUC = 0.65, r = 0.33) and E/VP (AUC = 0.69, r = 0.30), P < 0.01, whereas the decrease in E/A ratio during Valsalva maneuver failed to reach significance. Similar results were observed when echocardiographic parameters were used to estimate the left ventricular diastolic pressure before atrial contraction. CONCLUSIONS: PVR-A enabled the most accurate estimation of LVEDP. TDI-derived indices E/E' and MVG are also reliable alternatives superior to the classical Valsalva maneuver to detect a pseudonormal transmitral Doppler profile.     

Tissue Doppler imaging for the diagnosis of coronary artery disease

PURPOSE OF REVIEW: Tissue Doppler imaging (TDI) is a diagnostic method that provides quantitative data about myocardial function. The present review discusses the most recent developments in the application of TDI in coronary artery disease. RECENT FINDINGS: The most widely used TDI modality is velocity imaging, and systolic function is measured as peak velocity during LV ejection. Several recent studies show that TDI measurements during the LV isovolumic phases provide unique information regarding myocardial dysfunction. Since velocity imaging is confounded by influence from velocities in other segments, the TDI-based modalities strain- and strain rate imaging (SRI) have been introduced to measure regional shortening fraction and shortening rate, respectively.Velocity imaging during stress echocardiography has been validated clinically and appears equivalent, but not superior to conventional visual assessment of grey scale images. Potentially, more comprehensive evaluation that includes the use of SRI may improve the diagnostic power of TDI further. Preliminary reports suggest that TDI may have an important role in the assessment of viability in acute coronary occlusion, but this needs to be demonstrated in appropriately designed clinical trials. SUMMARY: At the present time tissue Doppler velocity imaging can be recommended for clinical use, especially the pulsed mode. Strain rate imaging may be useful as additional imaging, but needs further refinement before it is ready for routine clinical use.     

Tissue Doppler imaging for predicting outcome in patients with cardiovascular disease

PURPOSE OF REVIEW: Tissue Doppler imaging is being increasingly used for assessing global ventricular function in systole and diastole, and for quantifying regional wall motion abnormalities both in systolic heart failure with mechanical dyssynchrony and ischemic heart disease. Its use as a predictive tool is recent and the authors review publications relating to this aspect. RECENT FINDINGS: Peak early diastolic mitral annular velocity is a powerful predictor of outcome in a variety of cardiovascular conditions and adds incremental value to clinical parameters and standard mitral Doppler inflow velocities. Tissue Doppler imaging can also predict the development of hypertrophic cardiomyopathy in asymptomatic individuals carrying the genetic mutation even before the onset of overt left ventricular hypertrophy. In addition, the standard deviation of the time to peak systolic velocity is a good marker of mechanical asynchrony and can predict reverse remodeling. It may also be useful in identifying individuals with ischemic heart disease and regional wall motion abnormalities who have an adverse outcome. SUMMARY: Tissue Doppler imaging is a powerful new echocardiographic tool that is now becoming the standard for assessing ventricular function in a variety of situations and diseases.     

Diagnosis of cardiac amyloidosis based on the myocardial velocity profile in the hypertrophied left ventricular wall

The myocardial velocity profile (MVP), derived from color-coded tissue Doppler imaging (TDI), can identify transmural heterogeneity based on the physiology and pathology of the myocardium. This study sought to clarify whether the MVP can differentiate cardiac amyloidosis from other causes of left ventricular hypertrophy. We recorded the MVP and determined its myocardial velocity gradient (MVG) in the ventricular septum and left ventricular posterior wall using color-coded TDI in 10 patients with cardiac amyloidosis, in 25 patients with hypertensive hypertrophied left ventricular wall, in 25 patients with asymmetric septal hypertrophy of hypertrophic cardiomyopathy, and in 20 clinically normal controls. End-diastolic ventricular septal thickness was similar among the cardiac amyloidosis, hypertension, and hypertrophic cardiomyopathy groups. Percent systolic thickening of the ventricular septum and left ventricular posterior wall calculated from M-mode left ventricular echocardiograms was lower in the cardiac amyloidosis group than in the hypertension, hypertrophic cardiomyopathy, or control group. Peak MVGs during systole and early diastole were lowest in the cardiac amyloidosis group, followed, in order, by the control, hypertension, and hypertrophic cardiomyopathy groups. The systolic and early diastolic MVPs in the ventricular septum and left ventricular posterior wall showed a characteristic serrated pattern in all patients with cardiac amyloidosis, but not in any other patient groups. In conclusion, MVPs in the ventricular septum and left ventricular posterior wall show a distinctive serrated pattern that may be related to amyloid deposition in the myocardium. Myocardial tissue characterization using color-coded TDI provides diagnostic information in patients with cardiac amyloidosis.     

Stress Echocardiography: Abnormal Tissue Doppler Imaging in the Absence of Cardiac Allograft Vasculopathy in Heart Transplant Recipients

Background: The most significant predictor of long‐term survival in heart transplant patients is the development of accelerated cardiac allograft vasculopathy (CAV). Several studies have demonstrated the usefulness of dobutamine stress echocardiography (DSE) for screening CAV, by detecting regional wall motion abnormalities. Tissue Doppler imaging (TDI)‐derived indices during DSE allow for the early detection of ischemic heart disease (IHD), prior to a reduction in regional or global systolic function. These indices include a reduction in annular systolic velocity (S′), a decrease in early diastolic annular velocity (E′), and prolongation of time to E′. In cardiac transplant patients, the application of these TDI abnormalities during DSE remains unknown. Objective: The objective of this study was to evaluate the pattern of (TDI‐derived indices of systolic and diastolic function during DSE in cardiac transplant patients without evidence of CAV. Methods: A retrospective evaluation of 30 patients (mean age 54 ± 11 years) who had both DSE and coronary angiography was performed. The control group consisted of 15 patients referred to rule out coronary artery disease while the study group consisted of 15 cardiac transplant patients referred for routine annual follow‐up. During each stage of DSE, tissue Doppler measurements of systolic (S′), early (E′), and late (A′) diastolic velocities of the lateral annulus were taken. Results: All 30 patients had normal DSE based on systolic regional function and normal coronary angiograms with no stenosis >50%. There was no difference in hemodynamic parameters during the DSE at baseline and with stress. Despite normal coronaries, cardiac transplant patients demonstrated lower S′, E′, and A′ velocities at peak stress compared to the control patients. Conclusion: Dobutamine‐induced augmentation of TDI velocities of the lateral annulus, normally observed in the absence of ischemia in nontransplanted adults, is reduced in cardiac transplant recipients.     

Two-dimensional strain imaging: a new echocardiographic advance with research and clinical applications

Over the past two decades the quest for quantitative evaluation of left ventricular function and regional wall motion has escalated, allowing several aspects of myocardial contractile patterns to be quantified, both during stress echocardiography and in the assessment of dyssynchrony. Most of the literature to date has used Tissue Doppler Imaging (TDI) techniques to assess essentially long-axis function due to the angle dependency of Doppler based techniques. This brief review introduces the early development, validation and potential clinical applications of a new technique of quantifying two-dimensional (radial and circumferential) strains and strain rates through tracking myocardial "speckles". In-vivo and in-vitro validation of this 2D-strain imaging technique has been undertaken and reached a point where it is considered ready for more widespread investigations into clinical utility. One important advantage over TDI techniques is that it is not limited by dependency on the angle of insonation. Several recent studies looking at ventricular function in specific groups of patients have reported practical ability to distinguish the abnormally from the normally contracting regions of ventricular walls. It provides new and complementary quantitative information about ventricular dyssynchrony and regional wall motion abnormalities. More research studies are needed to determine the sensitivity and specificity of the measurements obtained using this technique and define its strengths and limitations. In particular, whether the measured values correlate well with clinical outcomes will need to be established in longitudinal interventional studies. The clinical utilities of this technique over the coming years are likely to expand rapidly.