Preejectional left ventricular wall motion in normal subjects using Doppler tissue imaging and correlation with ejection fraction

Clinical Meaning of the Ratio of Brachial Pre-Ejection Period to Brachial Ejection Time in Patients with Left Ventricular Systolic Dysfunction

An increase in the ratio of the brachial pre-ejection period to brachial ejection time [pre-ejection period (PEP)/ET] is correlated with a decrease of left ventricular ejection fraction (LVEF). The current study was designed to test the hypothesis that the change value (Δ) of PEP/ET is a useful indicator of Δ LVEF in patients with left ventricular systolic dysfunction.We consecutively enrolled 104 patients with left ventricular systolic dysfunction (LVEF < 45%). PEP/ET, B-type natriuretic peptide (BNP), and LVEF were evaluated at baseline and at 6-month follow-up. Compared with the baseline measurements, the 6-month values of ΔLVEF, ΔBNP, and ΔPEP/ET were 9.8% ± 9.0% (from 36.3% ± 9.2% to 46.3% ± 12.5%, P < 0.001), -168.5 ± 255.4 (from 271.4 ± 282.5 to 104.1 ± 129.6, P < 0.001), and -0.060 ± 0.069 (from 0.413 ± 0.097 to 0.358 ± 0.079, P < 0.001), respectively. There were significant correlations between LVEF and PEP/ET and between LVEF and BNP in both the initial (r = -0.316, P = 0.001 and r = -0.598, P < 0.001, respectively) and 6-month follow-up (r = -0.307, P = 0.003 and r = -0.701, P < 0.001, respectively). The Steiger's Z test showed that BNP had a significantly stronger correlation with LVEF compared with the correlations between LVEF and PEP/ET in both the initial and 6-month studies (Z = 2.471, P = 0.013 and Z = 3.575, P < 0.001, respectively). There were also significant correlations between ΔLVEF and ΔPEP/ET (r = -0.515, P < 0.001) and between ΔLVEF and ΔBNP (r = -0.581, P < 0.001); however, there was no difference between the correlations for ΔLVEF and ΔPEP/ET versus ΔLVEF and ΔBNP (Steiger's Z = 0.600, P = 0.545).In patients with left ventricular systolic dysfunction not only ΔBNP but also ΔPEP/ET could be a simple indicator of predicting change of LVEF.

Ultra-high frame rate tissue Doppler imaging

We describe a new tissue Doppler imaging (TDI) method, ultra-high frame rate tissue Doppler imaging (UFR-TDI). With two broad transmit beams covering only the ventricular walls, we achieve 1200 frames/s in a four-chamber apical view. We examined 10 healthy volunteers to study the feasibility of this method. Ultra-high-frame-rate TDI provided peak annular velocities and time to peak S' intervals in good agreement with those measured with conventional TDI. Moreover, UFR-TDI provided additional information in early and late systole: In all subjects, the method was able to separate the timing of electrical activation, start of mechanical contraction, mitral valve closure and start of ejection. The earliest mechanical activation was seen before mitral valve closure. The method was also able to measure the propagation speed of the mechanical wave created by aortic valve closure.

The left ventricular intracavitary vortex during the isovolumic contraction period as detected by vector flow mapping

AIMS

The purpose of this study was to characterize left ventricular (LV) intracavitary flow during the isovolumic contraction (IVC) period in humans using vector flow mapping.

METHODS

Color flow Doppler imaging was performed from the apical long-axis view in 61 patients with heart failure and 58 healthy volunteers. Doppler flow data obtained during IVC were analyzed offline with vector flow mapping.

RESULTS

A large vortex was formed from the LV inflow toward the outflow during IVC. In normal subjects, the area of the vortex was sustained, but the flow volume decreased significantly during IVC (P < 0.001). A significant apex-to-base flow velocity gradient was shown along the outflow axis on aortic valve opening. However, both the area and flow volume of the vortex decreased more severely during IVC in the patients (P < 0.001). The apex-to-base flow velocity gradient along the outflow axis disappeared and a reversed velocity gradient was observed at the basal-mid level on aortic valve opening. In multivariate models, a decreased LV ejection fraction was the only independent predictor of the percentage decrease in area of the vortex during the IVC (P < 0.001), and a larger QRS width (P = 0.028) and LV end-systolic long diameter (P = 0.002) were independent predictors of the percentage decrease in flow volume of the vortex.

CONCLUSIONS

The vortex across the LV inflow-outflow region during IVC facilitates the ejection of blood during early systole, and an unsustained vortex may be associated with impaired cardiac function.

Early echocardiographic findings in β-thalassemia intermedia patients using standard and tissue Doppler methods

Heart complications are among the serious problems of patients with β-thalassemia intermedia. This study aimed to evaluate myocardial function in these patients. Clinical parameters and both standard Doppler and pulsed Doppler tissue imaging parameters were compared in 51 β-thalassemia intermedia patients (mean age, 17.05 ± 5.8 years) and 20 normal subjects (mean age, 17.81 ± 7.35 years, p = 0.98). In 11 patients (21.5%), pulmonary artery hypertension was detected. M-mode echocardiographic findings such as ejection fraction and fractional shortening did not show statistically significant changes (p > 0.005). Pulsed Doppler showed a significant difference in the early (E) to late diastolic (A) velocity ratio of the tricuspid and mitral valve between the patients and the control subjects (p < 0.05). In the pulsed tissue Doppler study, the peak systolic velocity of the septum (Ss), the peak atrial velocity of the septum (Aas), the peak systolic velocity of the tricuspid annulus (St), the peak early diastolic velocity of the tricuspid annulus (Eat), and the peak late diastolic velocity of the tricuspid annulus (Aat) were increased significantly (p < 0.05). The pulse tissue Doppler of the lateral mitral annulus did not change significantly (p > 0.005). The peak systolic velocity of the posterior wall and the peak late diastolic velocity of the anterior wall changed significantly (p < 0.05). This study showed that β-thalassemia intermedia patients with normal M-mode and two-dimensional echocardiography had statistically significant changes in pulsed Doppler and pulsed tissue Doppler imaging.

Transmural myocardial mechanics during isovolumic contraction

OBJECTIVES

We sought to resolve the 3-dimensional transmural heterogeneity in myocardial mechanics observed during the isovolumic contraction (IC) phase.

BACKGROUND

Although myocardial deformation during IC is expected to be little, recent tissue Doppler imaging studies suggest dynamic myocardial motions during this phase with biphasic longitudinal tissue velocities in left ventricular (LV) long-axis views. A unifying understanding of myocardial mechanics that would account for these dynamic aspects of IC is lacking.

METHODS

We determined the time course of 3-dimensional finite strains in the anterior LV of 14 adult mongrel dogs in vivo during IC and ejection with biplane cineradiography of implanted transmural markers. Transmural fiber orientations were histologically measured in the heart tissue postmortem. The strain time course was determined in the subepicardial, midwall, and subendocardial layers referenced to the end-diastolic configuration.

RESULTS

During IC, there was circumferential stretch in the subepicardial layer, whereas circumferential shortening was observed in the midwall and the subendocardial layer. There was significant longitudinal shortening and wall thickening across the wall. Although longitudinal tissue velocity showed a biphasic profile; tissue deformation in the longitudinal as well as other directions was almost linear during IC. Subendocardial fibers shortened, whereas subepicardial fibers lengthened. During ejection, all strain components showed a significant change over time that was greater in magnitude than that of IC. Significant transmural gradient was observed in all normal strains.

CONCLUSIONS

IC is a dynamic phase characterized by deformation in circumferential, longitudinal, and radial directions. Tissue mechanics during IC, including fiber shortening, appear uninterrupted by rapid longitudinal motion created by mitral valve closure. This study is the first to report layer-dependent deformation of circumferential strain, which results from layer-dependent deformation of myofibers during IC. Complex myofiber mechanics provide the mechanism of brief clockwise LV rotation (untwisting) and significant wall thickening during IC within the isovolumic constraint.

Detection of myocardial dysfunction in the presence of normal ejection fraction

Detection of subclinical myocardial involvement is of utmost importance in risk stratification and prognosis; the role of ejection fraction in the detection of subclinical disease may be unhelpful. Our aim was to evaluate the methodology and importance of early detection of myocardial involvement in the presence of normal ejection fraction. Most of the pertinent English and non-English articles published from 1980 to 2006 in Medline, Scopus, and EBSCO Host research databases have been reviewed. Serial assessment of systolic function with different techniques should be avoided, since imaging modalities and ejection fraction measurements are not interchangeable. Additional non-invasive tools still are needed for the identification of subclinical left ventricular dysfunction in certain diseases. The recognition of subclinical involvement will prompt initiation of specific therapy to prevent the development of overt left ventricular dysfunction. This also is needed for determining the best timing for intervention in asymptomatic patients with metabolic and valvular disorders.

Reduced systolic performance by tissue Doppler in patients with preserved and abnormal ejection fraction: New insights in chronic heart failure

BACKGROUND

Tissue Doppler imaging (TDI) is useful in the evaluation of systolic and diastolic function. It allows assessment of ventricular dynamics in its longitudinal axis. We sought to investigate the difference in systolic and diastolic longitudinal function in patients with chronic heart failure (CHF) with normal and reduced ejection fraction.

METHODS AND RESULTS

One hundred ten outpatients with CHF and 68 controls were included. Ejection fraction (EF) was obtained and longitudinal systolic (S) and diastolic (E' and A') wall velocities were recorded from basal septum. Group A (controls) were normal and CHF patients were classified by EF in Group B1: > 45% and B2: < or = 45%. In A, B1 and B2 the mean S peak was 7.74; 5.45 and 4.89 cm/s (p<0.001); the mean E' peak was 8.56; 5.72 and 6.1 cm/s (p<0.001); and the mean A' peak was 10.2; 7.3 and 5.3 cm/s (p<0.001). Also, isovolumic contraction and relaxation time were different among control and CHF groups, (both p<0.001). The most useful parameters for identifying diastolic CHF were IVRT and S peak, with area under ROC curves of 0.93 and 0.89. The cut-off of 115 ms for IVRT and 5.8 cm/s for S peak showed a sensitivity of 94 and 97%, with a specificity of 82 and 73%, respectively.

CONCLUSION

These findings suggest that impairment of left ventricular systolic function is present even in those with diastolic heart failure, and that abnormalities may have an important role to identifying the condition.

Longitudinal Isovolumic Displacement of the Left Ventricular Myocardium Assessed by Tissue Velocity Echocardiography in Healthy Individuals

Rapid myocardial isovolumic motions are reportedly involved in the left ventricular reshaping process and may contribute to total systolic myocardial shortening. In this study, the qualitative and quantitative analysis of longitudinal myocardial isovolumic displacement was performed in 49 healthy individuals (23 men and 26 women) in age groups 21 to 49 and 50 to 76 years using tissue velocity echocardiography. The obtained isovolumic contraction and relaxation displacement curves were biphasic and displayed a significant regional heterogeneity most probably reflecting active presystolic and postsystolic reshaping of left ventricular cavity. Besides some sex difference in younger individuals, there was an age-dependent lengthening of the isovolumic relaxation time and their motion components. Even if being of short duration, the longitudinal myocardial isovolumic displacement may accounted for as much as 14% of the total longitudinal myocardial shortening, a fact which should be taken into consideration when assessing left ventricular systolic function.

Renewed Interest in Preejectional Isovolumic Phase: New Applications of Tissue Doppler Indexes: Implications to Ventricular Dyssynchrony

There is renewed interest in isovolumic contraction (IC) in tissue Doppler echocardiography of the myocardial walls, which is revisited in this editorial with new regional velocity data. The aims are to recall traditional background information and to emphasize the need to master the rapidly evolving tissue Doppler procedures for the accurate display of brief IC. IC, a preejectional component of great physiologic interest, is very demanding in terms of ultrasound technology. The onset and end of its motion velocities should be unambiguously defined versus the QRS complex and ejection wall motion. This is a prerequisite for exploiting the new information as guidance toward new therapeutic strategies from a practical viewpoint. However, IC preload dependence should be kept in mind, because of its limited potential for contractility studies. Finally, when only duration measurements are made in the assessment of ventricular dyssynchrony, regional preejectional duration is the pertinent tool to single out the onset of ejection local wall motion.

Biphasic tissue Doppler waveforms during isovolumic phases are associated with asynchronous deformation of subendocardial and subepicardial layers

Subendocardial and subepicardial layers of the left ventricle (LV) are characterized with right- and left-handed helical orientations of myocardial fibers. We investigated the origin of biphasic deformations of the LV wall during isovolumic contraction (IVC) and relaxation (IVR). In eight open-chest adult pigs, strain rates were measured along the right- and left-handed helical directions in the LV anterior wall by implanting 16 sonomicrometry crystals. Sonomicrometry strain rates were compared with the longitudinal subendocardial strain rates obtained by tissue Doppler imaging. During ejection and diastolic filling, shortening and lengthening occurred synchronously along the right- and left-handed helical directions. However, during IVC and IVR, the deformations were dissimilar in the two directions. Transmural shortening during IVC occurred along the right-handed helical direction and was accompanied with transient lengthening in the left-handed helical direction. Conversely, during IVR, the LV lengthened along the left-handed helical direction and shortened in the right-handed helical direction. Peak subendocardial strain rates obtained by tissue Doppler imaging during IVC and IVR correlated with corresponding sonomicrometry strain rate values obtained along the right- and left-handed helical directions ( r = 0.81, P < 0.001 and r = 0.70, P = 0.001, respectively). Our data suggest that brief counterdirectional movements occur within the LV wall during IVC and IVR. Shortening along the right-handed helical direction is accompanied with reciprocal lengthening in the left-handed helical direction during IVC and vice versa during IVR. The results support an association between asynchronous deformation of subendocardial and subepicardial muscle fibers and the biphasic isovolumic movements observed with high-resolution tissue Doppler imaging.

A new Doppler tissue ratio to revisit systole: The pre-ejectional isovolumic to ejectional velocity ratio–application to aging

Most diagnostic applications of Doppler tissue echocardiography rely on peak (Pk) velocity (V) values of single variables or myocardial V gradient. Whereas age-related changes in diastolic V are well-known, previous Doppler tissue echocardiography studies of systolic function showed no age effect for pre-ejectional (Ej) isovolumic (PEI) and Ej inward wall motion Pk V. In addition to myocardial V gradient, ratios were calculated between PEI and Ej Pk V, and mean V averaged over systole (PEI/Ej V ratios) at each layer of the posterior wall using M-mode color on two control groups: A (27 +/- 5 years) and B (54 +/- 10 years). The only changes were for PEI/Ej V ratios (mean V endocardial 21 +/- 7% vs 34 +/- 20%, P = .01; mean V epicardial 27 +/- 8% vs 40 +/- 18%, P = .006; Pk epicardial V 21 +/- 10% vs 30 +/- 16%, P = .04 for groups A and B, respectively). Correlation versus age were r = 0.52 and P = .005 (mean V endocardial), r = 0.50 and P = .007 (mean V epicardial), and r = 0.32 and P = .03 (Pk epicardial V). PEI/Ej V ratios and mean V studied in separate layers showed that the new systolic approach had advantages over single variable or Pk V to study age-related changes.

Pulsed tissue Doppler imaging detects early myocardial dysfunction in asymptomatic patients with severe mitral regurgitation

OBJECTIVE

To assess whether tissue Doppler myocardial imaging (TDI) indices can predict postoperative left ventricular function in patients with mitral regurgitation (MR) after surgical correction.

METHODS

84 patients (mean (SD) age 54.3 (10.8) years) with asymptomatic severe MR, an end systolic diameter < 45 mm, and an ejection fraction (EF) > 60% were subdivided in two groups: 43 patients with a postoperative EF reduction < 10% (group 1) and 41 patients with a postoperative EF reduction > or = 10% (group 2).TDI systolic indices of the lateral annulus were analysed preoperatively to assess myocardial systolic wave (Sm) velocity, myocardial precontraction time (PCTm), myocardial contraction time (CTm), and the PCTm:CTm ratio.

RESULTS

Postoperative EF decreased significantly (from 67 (5)% to 60 (5.5)%, p = 0.0001). Group 2 had a higher PCTm, CTm, and PCTm:CTm ratio and a lower Sm velocity than group 1 (PCTm 100.4 (19) ms v 82 (21.8) ms, p = 0.004; CTm 222 (3.1) ms v 215 (2.3) ms, p = 0.01; PCTm:CTm 0.45 (0.08) v 0.38 (0.09), p = 0.001; Sm velocity 10.4 (1.1) cm/s v 13 (1.3) cm/s, p = 0.0001). Multivariate regression analysis showed that the combination of PCTm:CTm ratio > or = 40 ms and Sm velocity < or = 10.5 cm/s was the main independent predictor of postoperative EF reduction > or = 10% (sensitivity 78%, specificity 95%).

CONCLUSIONS

TDI systolic indices can predict postoperative left ventricular function in patients with asymptomatic MR undergoing surgical correction.

Tissue Doppler, strain, and strain rate echocardiography for the assessment of left and right systolic ventricular function

Tissue Doppler (TDE), strain, and strain rate echocardiography are emerging real time ultrasound techniques that provide a measure of wall motion. They offer an objective means to quantify global and regional left and right ventricular function and to improve the accuracy and reproducibility of conventional echocardiography studies. Radial and longitudinal ventricular function can be assessed by the analysis of myocardial wall velocity and displacement indices, or by the analysis of wall deformation using the rate of deformation of a myocardial segment (strain rate) and its deformation over time (strain). A quick and easy assessment of left ventricular ejection fraction is obtained by mitral annular velocity measurement during a routine study, especially in patients with poor endocardial definition or abnormal septal motion. Strain rate and strain are less affected by passive myocardial motion and tend to be uniform throughout the left ventricle in normal subjects. This paper reviews the underlying principles of TDE, strain, and strain rate echocardiography and discusses currently available quantification tools and clinical applications.

Clinical relevancy of the myocardial velocity gradient: limitations of a binary response

BACKGROUND

Doppler tissue echocardiographic myocardial velocity gradient (MVG) overcomes translational or tethered motion effects. Diagnostic applications rely on MVG numeric value, an instantaneous value calculated at peak endocardial velocity. Our aim was to test the clinical relevancy of MVG for patients with dilated cardiomyopathy (CM) at rest. Efficiency of MVG, as a marker of the underlying mechanism, ischemic or nonischemic, was compared with that of mean velocities averaged over a cycle.

METHODS

Peak and mean velocities were measured and MVG calculated during ejection, and early and late diastole, in the endocardium and epicardium on color M-mode Doppler tissue echocardiographic parasternal recordings of the posterior wall, simultaneously imaged with the septum. The population consisted of 34 patients with similar clinical presentation (left ventricular ejection fraction < 40%, left ventricular end-diastolic diameter > 6 cm, and proven ischemic [14] or nonischemic [20] dilated CM) and 16 control subjects.

RESULTS

Doppler tissue echocardiography data significantly differed between control subjects and all patients with CM. Between patients, the only significant differences were found at the posterior wall for mean velocities at the epicardium in systole (9 +/- 4 mm/s for ischemic vs 14 +/- 5 mm/s for nonischemic, P =.002), and at both layers in early diastole (endocardium, 14 +/- 9 vs 29 +/- 12 mm/s, P =.0004; epicardium, 12 +/- 4 vs 22 +/- 11 mm/s, P =.002; ischemic vs nonischemic CM, respectively).

CONCLUSION

Specific features of CM were characterized by myocardial velocity changes studied layer by layer throughout a phase. The binary response of transient peak MVG could not reach this goal.

Dynamic myocardial velocity changes between phases of the cardiac cycle

The purpose of this study was 1. to define relationships between myocardial velocities according to phases and the range of dynamic phasic changes in controls using tissue Doppler echocardiography (TDE); 2. to compare the usefulness of dynamic changes vs. peak velocities alone on controls and patients. Peak velocity changes between phases were studied by colour M-mode TDE in the posterior wall from pre-ejection to systole (ejectional wall velocity increase) and from ejection to early diastole (early diastolic wall velocity increase) in 17 age-matched controls and a group of 30 patients with dilated cardiomyopathies (CMy) consisting of ischaemic (14) and nonischaemic (16) CMy with similar clinical and echocardiographic presentations. Systolic were correlated with early diastolic peak velocities (r = 0.79 p < 0.0001). Velocity values were significantly lower in patients than in controls (p < 0.001) as well as dynamic ejectional (p = 0.02) and early diastolic (0.03) increases. Dynamic changes were closely similar to controls (74 +/- 7%, 46 +/- 14%) in nonischaemic CMy (66 +/- 18%, 39 +/- 10% NS, respectively), but markedly reduced in ischaemic CMy (28 +/- 59%, and 26 +/- 31%, p = 0.005 and p = 0.06 vs. nonischaemic CMy, respectively). Of patients with ischaemic CMy, 78% had an ejectional increase < 40% and/or an early diastolic increase < 25%. Thus, correlation exists between systolic and early diastolic velocities. Normal range of dynamic changes was defined in an elderly population. Results suggest that velocity dynamics might be more informative than peak velocities alone to show left ventricular dysfunction.

Peak mean myocardial velocities and velocity gradients measured by color M-mode tissue Doppler imaging in healthy cats

We sought to assess the feasibility of recording the myocardial velocity gradients (MVGs) and mean myocardial velocities (MMVs) measured by color M-mode tissue Doppler imaging (TDI) in the free wall of unsedated normal cats (n = 18) with a 7.4-MHz probe equipped to record TDI images. The peak MVG and MMV values during the different phases of the cardiac cycle corresponded to certain color velocity patterns occurring in the left ventricular free wall (LVFW). Biphasic shifts were recorded in the tracings of both the MVG and MMV during early diastole (E1 and E2) as well as during the isovolumic relaxation (IVR) and isovolumic contraction (IVC) phases. Stepwise regression analysis showed that age was the only significant predictor for the peak MVG values during the 2nd phase of early diastole (E2) (r = -0.79, r2 = 0.63, and P < .001). The peak late diastolic MVG values were associated positively with age (r = 0.50, r2 = 0.25, and P < .05). The peak MMV values showed a negative association with age during E2 (r = -0.71, r2 = 0.50, and P < .001) as well as during early systole (Se) (r = -0.55, r2 = 0.30, and P < .05) and late systole (SI) (r = -0.62, r2 = 0.39, and P < .01). A positive association was found between age and the peak MMV values during late diastole (r = 0.54, r2 =- 0.29, and P < .05). The MVG values showed cyclic variations consistent with wall thickness changes. The accuracy of velocity determination and the spatial resolution of the system used were validated with a phantom. To our knowledge, this study is the 1st report of the application of this technique to the myocardium of cats,providing insights into the physiology of myocardial motion. It provides reference ranges of the peak MVG and MMV values for future studies of feline myocardial diseases.

Myocardial time intervals preceding left ventricular filling in chronic coronary artery disease: value of a decreased septal ejection time

The aim was to assess the capabilities of a two-segment myocardial recording to recognize patients with an underlying chronic ischemic process as a fast screening from controls, prior to the usual segment-to-segment tissue Doppler echocardiographic assessment of ischemia. Ischemia generates systolic and relaxation abnormalities. A flow Doppler index of global systolic and diastolic myocardial performance was recently drawn from time durations studied by coupling isovolumic relaxation (IR) to preejection (PEP)/ejection (ET) ratio (PEP/ET). We derived a similar tissue Doppler approach to the period preceding the left ventricular filling: PEP', the ejectional inward wall motion representing ET' and the prefilling (PreFg) period ranging from the end of ET' to the onset of the outward wall motion approximating IR, were measured and ratios calculated between variables. Spectral tissue Doppler was applied to septal and posterior walls of 28 patients with proven chronic coronary artery disease and preserved left ventricular function and of 12 age-matched controls. Data were compared with global flow data. Global information did not differentiate both groups, save for IR (sensitivity 32%, specificity 57%). In patients, tissue Doppler mean values of single variables (P=0.004-0.0006) and ratios (P=0.03-0.002) significantly differed from controls. Moreover, septal ET' differentiated 13 patients with one-vessel (219+/-34 ms) from 10 with two-vessel disease (158+/-70 ms, P=0.01). Sensitivity and specificity of a septal ET'<190 ms for a two-vessel disease were 80%. The two-segment tissue Doppler echocardiographic study provided a rapid screening of patients versus controls and helped to predict the number of diseased vessels.

Assessment of left and right ventricular systolic and diastolic synchronicity in normal subjects by tissue Doppler echocardiography and the effects of age and heart rate

OBJECTIVES

This study examined inter- and intraventricular synchronicity in systole and diastole by tissue Doppler imaging (TDI), and investigated if these parameters and the regional velocities were affected by age and heart rate.

METHODS

TDI was performed in 106 normal subjects (64.3 +/- 9.5 years, 60% male) using three apical views and a six-basal, six mid-segmental model. The regional parameters measured off line in both ventricles included peak isovolumic contraction velocity IVC(M), peak sustained systolic velocity (SM), peak early diastolic velocity (EM), peak late diastolic velocity (AM), and the E/AM ratio, as well as their time to these peak velocities: T(IVC), T(S), T(E), and T(A).

RESULTS

The systole and diastole within the left ventricle (LV) was highly synchronized without difference in T (IVC), TS, TE, and TA. However, the right ventricle (RV) was about 20 msec later than the LV for T(IVC) and TS. For regional velocities, IVC(M), S(M), E(M), and A(M) were significantly higher in basal than mid-segments (all P < 0.001). In the base of the LV, SM, and EM were the highest at the lateral segment and the lowest at the anterolateral segment. Age and heart rate did not affect systolic velocities or the timing of events. In diastole, age correlated negatively with EM(r =-0.36 to -0.48, P <or= 0.001)and E/AM ratio(r =-0.37 to -0.51, P <or= 0.01), while increasing heart rate affected AM (r = 0.17 to 0.43) positively and TE(r =-0.49 to -0.66, P < 0.001)and TA(r =-0.85 to -0.93, P < 0.001)negatively.

CONCLUSION

(1). Systolic and diastolic functions of the normal hearts are highly synchronized, though LV contraction slightly preceded that of RV. (2). Age and heart rate predominantly affect the diastolic, but not systolic, parameters that need to be taken into account.

Doppler tissue echocardiographic features of cardiac amyloidosis

The purpose of the study was to assess whether quantification of myocardial involvement by Doppler tissue echocardiography (DTE) enhances the accuracy of echocardiographic characterization of cardiac amyloidosis (CA). A group of 36 patients with CA (mean age 58 +/- 13 years; 22 male) and 40 age-matched control patients were studied. Patients with CA were divided into CA-1 subgroup with nonrestrictive (n = 22) and CA-2 with restrictive left ventricular (LV) filling pattern (n = 14). Peak lateral and medial mitral annulus velocities by pulsed wave DTE were measured in systole, early diastole, and late diastole. Using color M-mode DTE of the LV posterior wall, mean myocardial velocities (MMV) and myocardial velocity gradient (MVG) were measured during ventricular ejection, early and late isovolumic relaxation (IVR), rapid ventricular filling, and atrial contraction. In both CA-1 and CA-2 groups, mitral annulus velocities, MMV, and all MVG were lower than those measured in control patients, with the exception of peak late diastolic annulus velocities at lateral side and MMV in atrial contraction. MVGs in both early IVR and rapid ventricular filling were lower in the CA-1 as compared with the CA-2 group. Late IVR-MVG was negative in control patients and positive in patients with CA indicating a faster movement of the subendocardium rather than the subepicardium during late IVR in patients with CA (0.88 +/- 0.50 s(-1) vs -0.40 +/- 1.59 s(-1); P <.001). The following parameters: peak early diastolic annulus velocities at lateral side < or = -12 cm/s, peak early diastolic annulus velocities at medial side < or = -10 cm/s, early IVR-MMV < or = -2.5 cm/s, early IVR-MVG < or = -0.7 s(-1), and late IVR-MVG > or = 0.5 s(-1) differentiated patients with CA from control patients with an overall accuracy of 0.82, 0.83, 0.81, 0.87, and 0.81, respectively. In patients with CA, reduction in early IVR-MMV was independent of patients' age and LV mass. DTE indices proved helpful in differentiating patients with CA from control patients including those patients with CA who had borderline conventional echocardiographic features and nonrestrictive LV filling pattern.

Tissue Doppler imaging for the assessment of left ventricular systolic and diastolic functions

Doppler tissue imaging is a technique that allows recording of the low Doppler shift frequencies of high energy generated by the ventricular walls motion that are purposely filtered out in standard Doppler blood flow studies. Doppler tissue imaging can be performed with the use of pulsed Doppler, color two-dimensional Doppler, and color M-mode Doppler. Pulsed Doppler tissue imaging offers a high temporal resolution and therefore can be appropriately used for analysis of temporal relation between myocardium systolic and diastolic velocity waves. Color two-dimensional Doppler provides a good spatial resolution that permits differentiation of the velocity profiles between subendocardial and subepicardial layers but is limited by its poor temporal resolution. M-mode color-coded tissue imaging is characterized by a high spatiotemporal resolution, but sampling is only performed on a single line. Both two-dimensional and M-mode color-coded tissue imaging require specific modification of the current ultrasound machines. The present article reviews how Doppler tissue imaging may contribute to the noninvasive assessment of systolic and diastolic myocardial functions.

Comparison of myocardial tissue Doppler with transmitral flow Doppler in left ventricular hypertrophy

We sought to determine the most useful echocardiographic measurements for assessment of diastolic function in patients with left ventricular hypertrophy (LVH) and normal systolic function. We compared myocardial Doppler velocities of the basal inferoposterior wall with mitral inflow pulsed wave Doppler velocities in 11 healthy volunteers (age, 36 +/- 6 years), 25 patients (age, 64 +/- 14 years) without LVH, and 37 patients (age, 67 +/- 14 years) with LVH and otherwise normal echocardiograms. The discriminatory measurements were myocardial A-wave duration (120 +/- 18 versus 98 +/- 20 and 92 +/- 12 ms, P <.0001), myocardial isovolumetric relaxation time (124 +/- 45 versus 95 +/- 48 and 78 +/- 25 ms, P =.0035), mitral A-wave velocity (0.98 +/- 0.37 versus 0.73 +/- 0.28 m/s and 0.61 +/- 0.22 m/s, P =.009), and mitral E-wave deceleration time (257 +/- 93 versus 201 +/- 85 ms and 184 +/- 83 ms, P =.015), which were significantly increased, and myocardial E-wave velocity (0.84 +/- 0.04 m/s versus 0.13 +/- 0.03 m/s and 0.14 +/- 0.03 m/s, P <.0001), which was significantly decreased, in patients with LVH compared with patients without LVH and normal volunteers, respectively. Left ventricular posterior wall thickness correlated with myocardial isovolumetric relaxation time (r = 0.52, P <.0001) and myocardial A-wave duration (r = 0.59, P <.0001), negatively with myocardial E wave (r = -0.43, P <.0001), and showed no correlation with mitral inflow parameters except mitral inflow A wave (r = 0.43, P =.002). On multivariate analysis using these variables, myocardial isovolumetric relaxation time (P =.0014) and A-wave duration (P =.001) were the only 2 variables that correlated with posterior wall thickness (multiple R = 0.71). In the presence of LVH and preserved left ventricular systolic function, myocardial relaxation time and velocities are more sensitive than mitral Doppler inflow parameters in detecting abnormal left ventricular relaxation.

Tissue Doppler echocardiography

Tissue Doppler echocardiography (TDE) is a relatively recent addition to the diagnostic ultrasonographic examination. This is similar to routine Doppler ultrasonography to assess blood flow, but technologic features focus on lower velocity frequency shifts. Two techniques are used to assess myocardial function: pulsed TDE and color-coded TDE. A great deal of data has been generated on TDE over the last 5 years, and this review allows for only a small portion of these emerging data to be discussed. One clinical application is to assess peak systolic mitral annular velocity from the apical windows as an index of global ventricular function. The six-site average for peak systolic mitral annular velocity by the color-coded TDE method of greater than 5.4 cm/sec is predictive of an ejection fraction greater than 50% with an 88% sensitivity and a 97% specificity. An emerging application is to use pulsed-TDE to assess ventricular filling pressures. The mitral annular to inflow ratio (E/Ea) greater than 10 is predictive of a mean pulmonary capillary wedge pressure greater than 15 mm Hg with a 92% sensitivity and 80% specificity. Another application is to use peak early diastolic velocity to help differentiate constrictive pericarditis from restrictive cardiomyopathy. Peak early diastolic velocity is blunted with restrictive cardiomyopathy and preserved with constrictive pericarditis. These are just a few of the many evolving clinical applications of this new quantitative diagnostic ultrasonographic method.

Mean myocardial velocity mapping in quantifying regional myocardial contractile reserve in patients with impaired left ventricular systolic function: Doppler myocardial imaging study

The aim of this study was to use Doppler myocardial imaging-derived mean myocardial velocity (MMV) at baseline and during low-dose dobutamine stress echocardiography (DSE) to quantify regional contractile reserve of the left ventricle (LV). Sixteen patients (mean age 59 +/- 7 years) with coronary artery disease and regional left ventricular wall motion abnormalities were studied. During each increment of Dobutamine infusion, 6 2-dimensional transthoracic apical images were acquired in standard gray-scale and Doppler myocardial imaging modes at 30 degrees steps over 180 degrees. For the analysis, the LV was divided into 18 segments. For each segment, both wall motion score and MMV obtained in systole and both early and late diastole were measured at baseline and at each stage of DSE. In viable segments by wall motion score, MMV increased during DSE in systole and in early and late diastole. In contrast, in nonviable segments, MMV did not change during DSE. Mean myocardial velocity mapping is a promising new approach to quantify regional myocardial contractile reserve of the LV.

Assessment of myocardial velocities in healthy children using tissue Doppler imaging

The objective was to determine the normal range of tissue velocities in paediatric hearts as measured by tissue Doppler imaging. A prospective study was carried out involving 160 healthy children (mean age 10.8 y, range 4.0-17.9 y). Using tissue Doppler imaging (TDI) from parasternal long axis and apical views, peak velocities and peak myocardial velocity differences across the right ventricular anterior wall, interventricular septum and left ventricular posterior wall were assessed during systole, early and late diastole. The existence of transmyocardial velocity differences between the left and right side of the interventricular septum, as well as between the endocardium and epicardium of the left ventricular posterior wall was observed throughout the heart cycle. With range-gated TDI from apical four-chamber view, peak velocities were measured within the basal, mid and apical parts of the interventricular septum, and the left and right free ventricular walls. The highest peak systolic, early and late diastolic velocities were measured within the basal parts of all myocardial walls. The ranges of the calculated velocity ratios (early-to-late diastolic velocity and early diastolic-to-systolic velocity) for the various wall parts appeared to be overlapping. The correlations of peak myocardial tissue velocities and their ratios with age and weight were weak and practically irrelevant. These normal values of peak myocardial velocities, transmyocardial velocity differences and the ratios of peak wall velocities can be used as reference values in future investigations of ventricular dysfunction in this age group.

The effect of long-term training on age-related left ventricular changes by Doppler myocardial velocity gradient

Myocardial velocity gradient (MVG) derived from Doppler myocardial imaging and standard echocardiographic parameters were used to investigate whether age-related left ventricular (LV) functional and/or structural changes are different in long-term training athletes than in those leading a sedentary life style. Eighty-nine athletes (64 men, mean age 38 years, range 18 to 64) and 105 age-matched sedentary normal subjects were enrolled into the study. The MVG was analyzed in all patients throughout the cardiac cycle, and peak values were measured in systole and in diastole during both rapid ventricular filling and atrial contraction. No differences were found in LV systolic and late diastolic function between athletes and sedentary normal subjects. However, athletes had higher peak E waves in early diastole (73 +/- 10 cm/s vs 68 +/- 10 cm/s, p <0.001) and rapid ventricular filling MVG (10.2 +/- 1.5 s(-1) vs 7.2 +/- 2.8 s(-1), p <0.001) than sedentary normal subjects, suggesting a better early relaxation pattern. From LV diastolic indexes, the rapid ventricular filling MVG age-related decrease was less pronounced in athletes than in sedentary normal subjects (r = -0.39 vs r = -0.91; p <0.01). All other diastolic variables, including transmitral Doppler inflow, had a similar degree of age-related changes in both study groups. Thus, athletes, compared with those leading a sedentary lifestyle, have higher early diastolic performance, which is less affected by the physiologic aging process. It would appear that MVG derived from Doppler myocardial imaging may play an important role in the assessment of LV functional and/or structural changes.

Concordance between dobutamine Doppler tissue imaging echocardiography and rest reinjection thallium-201 tomography in dysfunctional hypoperfused myocardium

OBJECTIVE

To evaluate the efficiency of the new technique colour Doppler tissue imaging (DTI) by studying the concordance between dobutamine DTI, standard grey scale echocardiography (SE), and rest-reinjection TI-201 tomography (TI) in dysfunctional myocardium.

PATIENTS

23 patients with chronic wall motion abnormalities and proven coronary artery disease (> 70% diameter stenosis of at least one major coronary artery at angiogram).

METHODS

The contractile reserve and the resting perfusion characteristics of dysfunctional myocardial segments were assessed with low dose dobutamine SE and/or DTI (2.5 up to 20 gamma/kg/min) and TI on a semiquantitative basis. The DTI or SE data were separately compared with TI, on the basis of a 13 segment ventricular model. The resulting score of combined DTI and SE was also compared with TI. Finally the results obtained from DTI were compared with SE.

RESULTS

A total of 142 severely hypokinetic or akinetic segments were visualised. The viability study was feasible in 127 (89%) and 121 (85%) segments with DTI and SE, respectively. TI detected viability more frequently than DTI (84 v 61, p < 0.001) and SE (80 v 50, p < 0.001). However, as many viable segments were detected with combined DTI and SE as with TI (78 v 84, NS). The kappa values between TI and SE, DTI or combined SE and DTI were 0.38, 0.45, and 0.57, respectively, and increased to 0.52 and 0.76, respectively, for SE and DTI versus TI when mid-anterior and mid-inferior segments only were considered. The kappa value between SE and DTI was 0.34.

CONCLUSIONS

DTI is a helpful adjunct to SE, when using low dose dobutamine. This combination revealed as many viable segments as TI and showed a better agreement than DTI or SE alone for the assessment of myocardial viable segments evidenced by TI.

Quantitative Analysis of Tissue Doppler Data

A visual qualitative analysis of color Doppler myocardial images cannot show the low velocity changes in myocardial walls, and a quantitative analysis of tissue Doppler data is mandatory for an analysis of color Doppler myocardial recordings, including an assessment of myocardial velocity gradient across the thickness of the wall. Measurement of myocardial velocity in each pixel should provide access to a broader pathophysiological insight into regional contraction across wall thickness and into all myocardial segments throughout the cardiac cycle.

Evaluation of Hemodynamic Determinants of Quantitative Tissue Doppler Echocardiography in the Assessment of Left Ventricular Function

The aim of the present study was to determine whether quantitative tissue Doppler echocardiography has a role in the assessment of left ventricular hemodynamics. Thirty patients with suspected or known heart disease, but no wall motion abnormalities, took part in the study. Quantitative tissue Doppler echocardiography was performed using new software for digital analysis of the tissue Doppler signal. Average systolic subendocardial (S1), subepicardial (S2), and transmural (S3) wall velocity data were obtained from the inferoposterior wall and compared with the hemodynamics, including high fidelity pressure readings. S1 and S3 rates were found to be most reliable, being directly related to the peak rate of left ventricular pressure rise (dP/dt(peak)) and inversely to systemic vascular resistance (SVR) and resistance index (SVRI). The best correlation was between S1, dP/dt(peak), and SVRI (multiple regression analysis: r = 0.76, P < 0.0001; simple regression analysis relating S1 to dP/dt(peak)/SVRI: r = 0.77, SEE = 0.25, P < 0.0001). Thus, wall velocity indices as defined in this study have promise to become helpful in guiding the therapeutic modulation of inotropy and afterload in patients with heart failure.

Pulsed tissue Doppler imaging of left ventricular systolic and diastolic wall motion velocities to evaluate differences between long and short axes in healthy subjects

Our objective was to evaluate in healthy subjects the left ventricular (LV) wall motion velocities along the long and short axes by means of pulsed tissue Doppler imaging (TDI) to clarify the differences in the LV systolic and diastolic function between both axes. Wall motion velocities were recorded at the mid-wall portion of the middle site of the LV posterior wall in the parasternal long-axis view, and at the subendocardial portion of the middle site of the LV posterior wall in the apical long-axis view by pulsed TDI in 35 healthy subjects (mean age 26 +/- 10 years, mean heart rate 72 +/- 7 bpm). In all subjects, the LV pressure curve, its first derivative (dP/dt), the LV wall motion velocity, the phonocardiogram, and the electrocardiogram were simultaneously recorded. The systolic wave of the LV posterior wall motion velocity exhibited 2 peaks: the first and second systolic waves (Swl and Sw2, respectively). The diastolic wave also exhibited 2 peaks, the early diastolic and atrial systolic waves. The Swl along the long axis was greater than either the Sw1 and Sw2 along the short axis or the Sw2 along the long axis. The peak Sw1 along the long axis coincided with the peak dP/dt and was slightly earlier than the peak Swl along the short axis. The onset of Sw1 along the long axis coincided with the onset of the first heart sound. The Sw2 along the short axis was greater than that along the long axis. The early diastolic wave along the short axis was greater than that along the long axis, whereas the atrial systolic wave along the long axis was greater than that along the short axis. Thus, in healthy subjects, shortening of the longitudinal fibers predominated over that of the circumferential fibers during early systole, whereas shortening of the circumferential fibers predominated over the longitudinal fibers during the ejection phase. During diastole, the circumferential fibers predominated in the LV wall expansion at early diastole, whereas the longitudinal fibers predominated at atrial systole. In conclusion, pulsed TDI provided information that is useful in understanding the characteristics of LV wall motion along the long and short axes.

Comparison of 2 myocardial velocity gradient assessment methods during dobutamine infusion with Doppler myocardial imaging

Myocardial velocity gradient (MVG) has been shown to be the best quantitative parameter for the detection of ischemic myocardium during dobutamine infusion with the use of Doppler myocardial imaging. MVG has been previously assessed by velocity measurements across the thickness of the myocardium at the time of visually selected maximal color brightness (thickness-velocity plot method). We hypothesized that MVG could be assessed by velocity measurements throughout the cardiac cycle in the subendocardium parallel to the endocardial boundary to the left ventricular cavity and in the subepicardium parallel to the epicardial boundary (time-velocity plot method). This study was designed to compare MVG obtained from the thickness-velocity plot method and from the time-velocity plot method in quantifying dobutamine-induced changes in myocardial wall motion in 8 phases of the cardiac cycle on color M-mode Doppler myocardial imaging recordings of the left ventricular posterior wall performed in 8 conscious dogs at baseline and at steady state during dobutamine infusion (10 microg/kg per minute). For both methods, MVG was considered present if its mean value was significantly different from zero and if endocardial and epicardial velocities were significantly different. There was close agreement between the 2 methods. MVG was present during the preejection period, systole, rapid ventricular filling, and atrial contraction. Dobutamine induced a significant increase in MVG during the preejection period (from 2.64 +/- 0.83 to 4.05 +/- 0.81 seconds-1 ), systole (from 2.14 +/- 0.59 to 6.08 +/- 2.20 seconds-1 in early systole, from 1.90 +/- 1.06 to 5.31 +/- 2.95 seconds-1 in mid systole, from 1.37 +/- 0.57 to 2.44 +/- 0.53 seconds-1 in end systole), and rapid ventricular filling (from 3.06 +/- 1.12 to 7.82 +/- 2.58 seconds-1 ), related to a greater rise in endocardial than in epicardial velocities. The time-velocity plot method showed that ejection and diastole were 11% and 28% decreased during dobutamine infusion, respectively, as heart rate was 31% increased. Thus according to our quantitative criteria, both MVG assessment procedures enabled objective interpretation of dobutamine effects on left ventricular wall motion. In addition, the time-velocity plot method provided automatic detection of peak velocity, timing, and duration of wall velocity changes over time.

Developments in cardiovascular ultrasound. Part 3: Cardiac applications

Echocardiography is still the principal, non-invasive method of investigation for the evaluation of cardiac disorders. Using Doppler ultrasound, indices such as coronary flow reserve and cardiac output can be determined. The severity of valvular stenosis can be determined by the area of the valve, either directly from 2D echo, from pressure half-time calculations, from continuity equations or from the proximal isovelocity surface area method. Alternatively, the severity of regurgitation can be estimated by colour or pulsed ultrasound detection of the back-projection of the high-velocity jet into the chamber. Myocardial wall abnormalities can be assessed using 2D ultrasound, M-mode or analysis from the radio-frequency-ultrasound signal. Doppler tissue imaging can be used to quantify intra-myocardial wall velocities, and 3D reconstruction of cardiac images can provide visualisation of the complete cardiac anatomy from any orientation. The development of myocardial contrast agents and associated imaging techniques to enhance visualisation of these agents within the myocardium has aided qualitative assessment of myocardial perfusion abnormalities. However, quantitative myocardial perfusion has still to be realised.

Tissue Doppler imaging and the quantification of myocardial function

Tissue Doppler imaging (TDI) has recently been introduced in clinical echocardiography. Most widely used are tissue velocity maps, in which the velocity of moving tissue is calculated relative to the transducer from the Doppler shift and displayed as colour-encoded velocity maps in either M-mode or two-dimensional image formats (Doppler velocity mode). This allows detection and quantification of dyssynergic areas of the myocardium. Additionally, the velocities may be studied with pulsed wave-tissue Doppler sampling (PW-TDS) which displays the velocity of a selected myocardial region versus time with high temporal resolution. Less often used, are tissue acceleration maps which display acceleration or velocity change of subsequent frames as different colours (Doppler acceleration mode). These maps may find application in clinical electrophysiology. Another TDI modality is tissue energy imaging, which is based on the integration of the power spectrum of the Doppler signals from the tissue. This technique provides maps of Doppler energy which are represented as colour brightness. Such maps offer potential for the study of myocardial perfusion. TDI modalities have promise to become clinically useful for quantifying myocardial function.