Regional Left Ventricular Diastolic Dysfunction Evaluated by Pulsed-Tissue Doppler Echocardiography

The assessment of left ventricular diastolic function: guidance and recommendations from the British Society of Echocardiography

Impairment of left ventricular (LV) diastolic function is common amongst those with left heart disease and is associated with significant morbidity. Given that, in simple terms, the ventricle can only eject the volume with which it fills and that approximately one half of hospitalisations for heart failure (HF) are in those with normal/'preserved' left ventricular ejection fraction (HFpEF) (Bianco et al. in JACC Cardiovasc Imaging. 13:258-271, 2020. 10.1016/j.jcmg.2018.12.035), where abnormalities of ventricular filling are the cause of symptoms, it is clear that the assessment of left ventricular diastolic function (LVDF) is crucial for understanding global cardiac function and for identifying the wider effects of disease processes. Invasive methods of measuring LV relaxation and filling pressures are considered the gold-standard for investigating diastolic function. However, the high temporal resolution of trans-thoracic echocardiography (TTE) with widely validated and reproducible measures available at the patient's bedside and without the need for invasive procedures involving ionising radiation have established echocardiography as the primary imaging modality. The comprehensive assessment of LVDF is therefore a fundamental element of the standard TTE (Robinson et al. in Echo Res Pract7:G59-G93, 2020. 10.1530/ERP-20-0026). However, the echocardiographic assessment of diastolic function is complex. In the broadest and most basic terms, ventricular diastole comprises an early filling phase when blood is drawn, by suction, into the ventricle as it rapidly recoils and lengthens following the preceding systolic contraction and shortening. This is followed in late diastole by distension of the compliant LV when atrial contraction actively contributes to ventricular filling. When LVDF is normal, ventricular filling is achieved at low pressure both at rest and during exertion. However, this basic description merely summarises the complex physiology that enables the diastolic process and defines it according to the mechanical method by which the ventricles fill, overlooking the myocardial function, properties of chamber compliance and pressure differentials that determine the capacity for LV filling. Unlike ventricular systolic function where single parameters are utilised to define myocardial performance (LV ejection fraction (LVEF) and Global Longitudinal Strain (GLS)), the assessment of diastolic function relies on the interpretation of multiple myocardial and blood-flow velocity parameters, along with left atrial (LA) size and function, in order to diagnose the presence and degree of impairment. The echocardiographic assessment of diastolic function is therefore multifaceted and complex, requiring an algorithmic approach that incorporates parameters of myocardial relaxation/recoil, chamber compliance and function under variable loading conditions and the intra-cavity pressures under which these processes occur. This guideline outlines a structured approach to the assessment of diastolic function and includes recommendations for the assessment of LV relaxation and filling pressures. Non-routine echocardiographic measures are described alongside guidance for application in specific circumstances. Provocative methods for revealing increased filling pressure on exertion are described and novel and emerging modalities considered. For rapid access to the core recommendations of the diastolic guideline, a quick-reference guide (additional file 1) accompanies the main guideline document. This describes in very brief detail the diastolic investigation in each patient group and includes all algorithms and core reference tables.

Left atrial volume and function in patients with cardiac syndrome X assessed by real time three-dimensional echocardiography

OBJECTIVE

The aim of this study was to evaluate left atrial (LA) volume and function using real time three-dimensional echocardiography (RT3DE) in patients with cardiac syndrome X (CSX).

METHODS

Fifty patients with CSX (28 females; mean age 50.9±10.9 years) and 50 age- and gender-matched healthy controls (30 females; mean age 52.3±9.8 years) who had negative treadmill exercise test and normal coronary arteries on invasive coronary angiography were included in the study. Comprehensive two-dimensional (2D), pulsed and tissue Doppler, speckle tracking echocardiography, and RT3DE for the assessment of LA dynamics were performed in all study participants.

RESULTS

Cardiac syndrome X and control groups have similar clinical characteristics regarding age, sex, body mass index, hypertension, diabetes, and smoking habit. 2D echocardiographic parameters were also similar between groups. Pulsed- and tissue Doppler parameters, IVRT, A, and A_m values, were higher in CSX group, while E_m , E/A, and E_m /A_m ratios were higher in the control group reflecting mild diastolic dysfunction. Regarding RT3DE parameters, LA maximum volume, minimum volume, volume before atrial contraction, LA maximum volume index, total and active stroke volumes were found to be increased in CSX patients. However, LA total stroke fraction, passive stroke volume, passive stroke fraction, peak systolic, and diastolic longitudinal strains were found to be lower in CSX patients.

CONCLUSION

The main finding of this study was that CSX patients had altered LA booster pump, reservoir, and conduit functions. This finding may have clinical implications for early detection of abnormal LA dynamics in CSX patients.

Combination of single quantitative parameters into multiparametric model for ischemia detection is not superior to visual assessment during dobutamine stress echocardiography

Background

To evaluate if the combination of several quantitative parameters into a mathematical model would enhance the detection of myocardial ischemia during dobutamine stress echocardiography (DSE) when compared to conventional wall motion analysis.

Methods

In a prospective study design 151 patients (age 61.8 ± 9.2) in test group and 105 patients (age 64.0 ± 10.6) in validation group were selected and underwent DSE between January 2008 and December 2012. In all patients coronary angiography was performed within 6-8 weeks from DSE, considering at least one stenosis ≥50 % per patient as significant coronary artery disease (CAD). Results of DSE visual assessment and myocardial velocity, strain and strain rate parameters derived from speckle tracking imaging were imported automatically to an originally created software. A mathematical model calculating prognosis of at least one stenosis per patient and stenosis in separate arteries was constructed.

Results

Myocardial ischemia was visually detected in 60 (39.7 %) and in 58 (54.2 %) patients of the test and validation group, respectively. A total of 76 (50.3 %) patients in the test group and 69 patients (65.7 %) in the validation group had ≥50 % coronary stenosis. Sensitivity and specificity of the mathematical model per patient in the test group were 91.6 % and 86.3 % compared to 76.8 % and 89.0 % of the visual assessment, respectively. However, in the validation group the sensitivity, specificity, positive predictive value and negative predictive value dropped down significantly becoming lower to visual assessment.

Conclusions

Myocardial deformation imaging may potentially replace visual assessment with an automated predictive model for stress-induced ischemia detection. However, a multiparametric mathematical model based on quantitative deformation markers did not demonstrate incremental value to visual assessment of wall motion.

Tissue Doppler echocardiography predicts acute myocardial infarction, heart failure, and cardiovascular death in the general population

AIMS

To improve risk prediction of cardiovascular morbidity and mortality, we need sensitive markers of cardiac dysfunction; Echocardiographic Tissue Doppler Imaging (TDI) is feasible and harmless and may be ideal for this purpose.

METHODS AND RESULTS

Within the community-based Copenhagen City Heart Study, 2064 participants were examined by echocardiography including TDI and followed (median 10.9 years) with regard to cardiovascular death, heart failure, or acute myocardial infarction (n = 277). Impaired systolic (s') and diastolic (e' and a') function according to age and sex as assessed by TDI was associated with increased risk of the combined end point, even in the subgroup of persons with a normal conventional echocardiographic examination [per 1 cm/s decrease: s': HR 1.32 (1.12-1.57), P < 0.001; e': HR 1.17(1.04-1.31), P < 0.01; a': HR 1.17 (1.06-1.30), P < 0.005]. Interestingly, reduced early diastolic myocardial velocity (e') was associated with risk of acute myocardial infarction, whereas reduced systolic (s') or late diastolic function (a') was associated with heart failure and cardiovascular death independently of traditional risk factors, plasma proBNP, and conventional echocardiographic measures. Combining information on early and late diastolic function by TDI provided incremental prognostic information and improved risk classification (net reclassification improvement: 27%; P < 0.001) and remained a significant predictor of the combined end point even in the subgroup with a normal conventional echocardiographic examination [per cm/s decrease: HR 1.18 (1.08-1.28), P < 0.001].

CONCLUSION

In the general population, TDI identifies individuals with cardiac dysfunction and high risk of cardiovascular morbidity and mortality independently of traditional risk factors, even in persons with a normal conventional echocardiographic examination.

Quantitative approach using multiple single parameters versus visual assessment in dobutamine stress echocardiography

BACKGROUND

A number of myocardial Doppler-derived velocity, strain myocardial imaging parameters (DMI) and speckle tracking imaging (STI) have been proposed for the quantification of myocardial ischemia during stress echocardiography. The purpose of the study was to identify the best single ultrasound quantitative parameter for prediction of significant coronary stenosis and compare it with visual assessment during dobutamine stress echocardiography (DSE).

METHODS

Prospective analysis included data of 151 patients (age 61.8 ± 9.2) who underwent dobutamine stress echocardiography for known (n = 35) or suspected coronary artery disease (CAD) (n = 36) or symptomatic chest pain (n = 80), excluding patients with previous myocardial infarction. Systolic, post-systolic and diastolic velocities, strain and strain rate parameters were obtained at rest and at peak dobutamine challenge. Derivative markers as E'/A' ratio, post-systolic index and changes from rest to stress were calculated (98 parameters overall, predominantly longitudinal). Coronary angiography was chosen as reference method considering at least one stenosis ≥70% per patient as significant CAD. The predictive value of quantitative parameters and wall motion score index (WMSI) was obtained using logistic regression and ROC analysis.

RESULTS

The value of single parameters discriminated as independent predictors of CAD appeared to be modest (area under the curve [AUC] ranged from 0.63 to 0.72 for 16 PW-DMI, 12 CC-DMI and 12 STI markers), comparing to AUC of WMSI 0.88. Sensitivity, specificity and accuracy of visual DSE evaluation was 82.4% (95%CI 77.4%; 85.2%), 92.6% (95%CI 83.4%; 97.5%) and 86.0% (95%CI 79.5%; 89.6%), respectively, Youden index 0.75. Sensitivity, specificity and accuracy of single predictors ranged from 40.0% to 93.3% (95% CI 22.7%; 99.2%), from 34.2% to 88.7% (95% CI 25.6%; 94.1%) and from 45.8% to 80.0% (95% CI 37.5%; 87.2%) respectively, Youden index ranged from 0.20 to 0.52.

CONCLUSIONS

Multiple single quantitative parameters showed limited predictive ability to identify significant coronary artery stenosis. Visual assessment of DSE appears to be more accurate than single velocity and strain/strain rate markers in the diagnosis of CAD.

Tissue Doppler echocardiography improves the diagnosis of coronary artery stenosis in stable angina pectoris

Aim To determine if colour tissue Doppler imaging (TDI) performed at rest in patients with suspected stable angina pectoris (SAP) is able to predict the presence of significant coronary artery disease (CAD).

METHODS AND RESULTS

This study comprises 296 consecutive patients with clinically suspected SAP, no previous cardiac history, and a normal ejection fraction. All patients were examined by colour TDI, exercise electrocardiogram (ECG), and coronary angiography (CAG). Regional longitudinal systolic (s'), early diastolic (e'), and late diastolic (a') myocardial velocities were measured by colour TDI at six mitral annular sites and averaged to provide global estimates. Duke score (DS), including ST depression, chest pain, and exercise capacity, was used as the outcome of the exercise ECG. Patients with an area stenosis of ≥70% in at least one epicardial coronary artery were categorized as having a significant CAD (n= 108) and were compared with patients without significant CAD (n= 188). Both e' [odds ratio (OR): 1.5 (1.1-1.9, P < 0.01) per cm/s decrease] and s' [OR: 1.7 (1.1-2.5, P < 0.05) per cm/s decrease] remained independent predictors of CAD after multivariable adjustment for baseline, exercise ECG, and conventional echocardiographic parameters. Area under the receiver operating characteristic curve (AUC) for exercise ECG and TDI in combination was significantly higher than AUC for exercise ECG alone (0.84 vs. 0.79, P < 0.01).

CONCLUSION

In patients with suspected SAP colour TDI performed at rest is an independent predictor of significant CAD, and colour TDI improves the diagnostic performance of exercise ECG.

Evaluation of left atrial function in patients with coronary artery disease by two-dimensional strain and strain rate imaging

BACKGROUND

Left ventricular (LV) dysfunction in patients with coronary artery disease is shown by strain and strain rate imaging. However, left atrium (LA) function in patients with coronary artery disease (CAD) has not been assessed by this method.

METHODS AND RESULTS

In 34 CAD patients, including 17 patients with enlarged LA (LA diameter ≤ 4.0 cm) and 17 with normal-size LA (LA diameter ≤ 4.0 cm), two-dimensional strain echocardiographic imaging (2DSE) was performed. Twenty healthy subjects as a control group were included. Both conventional parameters and strain parameters, such as LA peak systolic strain (LAs S/SR), preatrial contraction strain (LAa S), peak systolic (LAs SR), early diastolic strain rate (LAe SR) and late diastolic strain rate (LAa SR), were measured. Conventional parameters were abnormal in CAD patients with enlarged LA (ELA), but there were no significant differences between CAD with normal-size left atrium (NLA) and control groups. LAs S/SR and LAe SR were lower in patients than in normal controls, and were even lower in CAD-ELA group (P < 0.05). LAa S/SR were lower in CAD patients with ELA (P < 0.05), but without a significant difference between CAD-NLA and control groups. A significant correlation was observed between LAs S/SR and LA emptying fraction (r = 0.85, P < 0.05; r = 0.72, P < 0.05, respectively). LAa S/SR related well to LA ejection fraction (r = 0.68, P < 0.05; r = 0.61, P < 0.05, respectively). LAs SR was most accurate in identifying both CAD patients with NLA from controls and CAD patients from controls (area under the curve: 0.91; 0.95, respectively).

CONCLUSIONS

LA diastolic dysfunction occurs prior to LA systolic dysfunction in CAD patients, and LAs SR is the most accurate index in identifying patients with CAD.

Tissue Doppler echocardiography reveals impaired cardiac function in patients with reversible ischaemia

AIMS

To determine if echocardiographic tissue Doppler imaging (TDI) performed at rest detects reduced myocardial function in patients with reversible ischaemia.

METHODS AND RESULTS

Eighty-four patients with angina pectoris, no previous history of ischaemic heart disease and normal left ventricular ejection fraction were examined with colour TDI, single-photon emission computed tomography (SPECT), and coronary angiography (CAG). Patients with a normal SPECT (n= 42) constituted the control group and patients with a positive SPECT (n= 42) were divided into patients with (true-positive SPECT, n= 30) or without (false-positive SPECT, n= 12) significant coronary stenoses assessed by CAG. Regional longitudinal systolic (s'), early diastolic (e'), and late diastolic (a') myocardial velocities were measured by colour TDI at six mitral annular sites and averaged to provide global estimates. In patients with reversible ischaemia both global systolic and diastolic function were impaired in terms of reduced average s' (5.6 ± 0.9 vs. 6.1 ± 1.1 cm/s; P< 0.05), reduced average e' (5.9 ± 1.8 vs. 7.0 ± 1.7 cm/s; P< 0.01) and increased average E/e' (14.2 ± 5.0 vs. 11.5 ± 3.9; P< 0.01). This impairment of the cardiac function was even more evident in patients with a true-positive SPECT with reduced average s' (5.5 ± 0.8 vs. 6.1 ± 1.1 cm/s; P< 0.01), reduced average e' (5.2 ± 1.5 vs. 7.0 ± 1.7 cm/s; P< 0.001), and increased average E/e' (15.5 ± 5.2 vs. 11.5 ± 3.9; P< 0.001), whereas no difference in myocardial velocities could be demonstrated in patients with a false-positive SPECT compared with controls.

CONCLUSION

In patients with stable angina pectoris, preserved ejection fraction, and reversible ischaemia assessed by SPECT, echocardiographic colour TDI performed at rest reveals impaired cardiac function. The impairment of the cardiac function seems to be evident only in patients with a true-positive SPECT and colour TDI may therefore increase its diagnostic value.

Myocardial dysfunction in fetuses exposed to intraamniotic infection: new insights from tissue Doppler and strain imaging

OBJECTIVE

The purpose of this study was to assess myocardial function of fetuses who were exposed to intraamniotic infection compared with fetuses of uncomplicated pregnancies by the application of tissue Doppler and strain rate (SR) imaging.

STUDY DESIGN

We evaluated the right ventricular function of fetuses with preterm premature rupture of membranes and proven intraamniotic infection (n = 12 fetuses) and healthy fetuses (n = 27). Tissue Doppler velocities during early diastolic relaxation (E(m)) and atrial contraction (A(m)) and early diastolic SR were measured as indices of diastolic function, whereas the peak systolic strain and SR were used as parameters of systolic function.

RESULTS

Fetuses with intraamniotic infection exhibit impairment in both diastolic and systolic performance, which was characterized by increased diastolic compliance (increased E(m)/A(m) ratio, increased early diastolic SR compared with the control fetuses), decreased systolic contractile function (reduced systolic strain and SR), and longitudinal myocardial dyskinesia.

CONCLUSION

New echocardiographic tools suggest that fetal heart is a target organ in the context of intraamniotic infection.

Transthoracic echocardiography in mice

In recent years, murine models have become the primary avenue for studying the molecular mechanisms of cardiac dysfunction resulting from changes in gene expression. Transgenic and gene targeting methods can be used to generate mice with altered cardiac size and function,^1-3 and as a result, in vivo techniques are needed to evaluate their cardiac phenotype. Transthoracic echocardiography, pulse wave Doppler (PWD), and tissue Doppler imaging (TDI) can be used to provide dimensional measurements of the mouse heart and to quantify the degree of cardiac systolic and diastolic performance. Two-dimensional imaging is used to detect abnormal anatomy or movements of the left ventricle, whereas M-mode echo is used for quantification of cardiac dimensions and contractility.^4,5 In addition, PWD is used to quantify localized velocity of turbulent flow,⁶ whereas TDI is used to measure the velocity of myocardial motion.⁷ Thus, transthoracic echocardiography offers a comprehensive method for the noninvasive evaluation of cardiac function in mice.

Global strain rate imaging for the estimation of diastolic function in HFNEF compared with pressure-volume loop analysis

AIMS

Strain rate imaging provides direct information on intrinsic myocardial function and may improve the diagnostic of diastolic dysfunction in heart failure with normal ejection fraction (HFNEF). We therefore correlated global strain with pressure-volume (PV) loop analysis and compared it with flow and tissue Doppler measurements.

METHODS AND RESULTS

Longitudinal two-dimensional strain rate and flow and tissue Doppler (TDI) indices were measured simultaneously and correlated with diastolic indices of PV relationship obtained by a conductance catheter in 21 patients with HFNEF and 12 controls. HFNEF patients showed a reduced global strain rate during isovolumetric relaxation (SR(IVR)) [0.27 (0.12-0.39) vs. 0.44 (0.29-0.56) s(-1), P = 0.028]. Global strain rate during early (SR(E)) and late (SR(L)) diastole did not defer from controls. Their ratios with early transmitral flow, E/SR(IVR) and E/SR(E), were both elevated in HFNEF [3.68 (2.57-7.52) vs. 1.73 (1.47-2.37) m, P = 0.007 and 1.13 (0.76-1.36) vs. 0.83 (0.57-1.04) m, P = 0.030]. SR(E) and SR(IVR) correlated with left ventricular (LV) relaxation τ (r = 0.40 and 0.47, P < 0.05); E/SR(IVR) and E/SR(E) with LV end-diastolic pressure (r = 0.49 and 0.57, P < 0.01) and LV stiffness constant β (r = 0.42 and 0.43, P < 0.01). Neither of the strain rate indices were significantly more accurate than TDI (area under the curve: SR(E) 0.55, SR(IVR) 0.70, E'/A' 0.72, E/SR(E) 0.75, E/SR(IVR) 0.80, and E/E' 0.83).

CONCLUSION

Strain rate imaging is accurate in detecting increased LV stiffness in HFNEF, but it is not superior to already established TDI analysis including E/E' in patients with only mild degree of disease.

[Echocardiography in mouse]

Assessing cardiac phenotype requires invasive or noninvasive techniques in mouse. Echocardiography is a noninvasive technique for evaluating cardiac function. The purpose of this paper is to underline echocardiography modalities and new tools Doppler applications like tissue Doppler imaging.

Segmental early relaxation phenomenon as determined by tissue Doppler imaging

BACKGROUND

The early diastolic peak velocity of left ventricular (LV) wall segment has always been thought to appear in the rapid filling phase. However, we find a segmental early relaxation phenomenon (SERP), characterized by an early diastolic peak velocity lying in the isovolumic relaxation (IVR) period. The present study aimed to investigate the characteristics of SERP segments with tissue Doppler imaging (TDI) echocardiography.

METHODS

TDI was performed in 119 patients with known or suspected coronary heart disease (CHD) and 60 normal subjects. The segmental early diastolic velocity pattern was classified as normal pattern (NP), postsystolic shortening (PSS) and SERP.

RESULTS

Segmental early diastolic velocity pattern was significantly associated with actual coronary diameter stenosis, relative coronary stenosis, wall motion score, and segmental location in LV wall. Compared with other segments, SERP segments had a higher IVR velocity and lower early diastolic peak velocity.

CONCLUSION

SERP most frequently occurs in the distribution of artery with the relatively mildest stenosis, and is more likely accompanied by simultaneous PSS elsewhere in LV wall, which occurs most frequently in the distribution of artery with the relatively most severe stenosis. A decreased early diastolic peak velocity of SERP segment dose not necessarily mean impaired myocardial relaxation.

Tissue Doppler velocity is not totally preload-independent: a study in a uremic population after hemodialysis

OBJECTIVES

The aim of this study was to investigate the changes of regional tissue Doppler velocity after volume removal following regular hemodialysis (HD) in uremic patients. Is tissue Doppler velocity really preload-independent?

BACKGROUND

Diastolic dysfunction was divided into four stages: normal pattern, abnormal relaxation pattern, pseudonormalization pattern, and restrictive pattern. Pulse wave Doppler and color Doppler echocardiography were important diagnostic tools for these forms of diastolic dysfunction. However, they were preload-dependent and sometimes there was confusion between the normal pattern and the pseudonormalization pattern. Tissue Doppler echocardiography was promising for problems in diastolic dysfunction and appeared to be preload-independent. However, there are still some disputes over this point.

METHODS

Ninety-three uremic patients receiving regular HD were included in the study. There were 45 males and 48 females aged 59 +/- 14 years. The mean volume removed after HD was 2.3 +/- 0.9 kg. The mean heart rates before and after HD were 77 +/- 11 and 76 +/- 12 beats per minute, respectively (p = 0.73). All patients received complete transthoracic echocardiography examinations before and after HD. The studies included cardiac chamber size, left ventricular systolic performance, pulse wave Doppler echocardiographic data of mitral inflow and the right upper pulmonary vein including peak velocity of early diastolic E wave, E wave time velocity integral (TVI-E), peak velocity of late diastolic A wave, A wave TVI, systolic phase of pulmonary vein (S wave TVI), early diastolic phase of pulmonary vein (D wave TVI) and atrial contraction phase of pulmonary vein (Ar wave TVI). Pulsed tissue Doppler echocardiography (TDE) was performed and a 4-mm sample volume was placed at the 6 corners of the mitral annulus including septal, lateral, anterior, inferior, anteroseptal and posterior corners. Five to ten cardiac cycles were recorded and the data were averaged. Measurements performed included peak velocity of systolic phase (Sa), early diastolic phase (Ea), late diastolic phase (Aa), Ea/Aa ratio and time from the beginning of electrocardiogram Q wave to the beginning of Sa (Q-Sa time). The same measurements were repeated after HD.

RESULTS

After HD, left atrium diameter and left ventricular internal dimensions at end diastole became smaller. There were significant reductions for mitral peak E wave velocity, TVI-E, peak A wave velocity and E/A ratio. As for the pulmonary vein, systolic phase of pulmonary vein and early diastolic phase of pulmonary vein decreased significantly. Peak Ar wave did not change significantly. For TDE, Sa and Aa did not change but Ea did decrease.

CONCLUSION

After HD, there is a significant reduction of intravascular effective volume. No significant change is found for myocardial peak systolic velocity and peak late diastolic velocity. However, there is a significant reduction of myocardial early diastolic phase peak velocity. This suggests that TDE is not completely preload-independent; at least, it is phase-dependent within each cardiac cycle.

Detailed analysis of myocardial motion in volunteers and patients using high-temporal-resolution MR tissue phase mapping

PURPOSE

To detect and investigate details in left ventricular (LV) motion patterns with a temporal resolution comparable to that of echocardiography.

MATERIAL AND METHODS

To assess global and regional myocardial motion in high temporal detail, respiratory-gated MR phase-contrast measurements with three-directional velocity encoding (venc) were performed in 12 healthy volunteers and two patients with LV hypertrophy in basal, midventricular, and apical locations of the LV with a temporal resolution of 13.8 msec.

RESULTS

The volunteer data revealed details in LV motion patterns that were known only from echocardiography. For all volunteers, characteristic myocardial motion patterns, such as triphasic global diastolic expansion, could be detected with high accuracy. One volunteer underwent an additional echocardiographic measurement in order to corroborate the complex motion features as measured by MRI. Patient examinations revealed substantial changes in diastolic function compared to motion patterns in healthy volunteers.

CONCLUSION

The proposed high-temporal-resolution velocity-mapping technique provides previously undetectable information on LV performance, and is highly promising for the detection of local and global motion abnormalities in patients with disturbed LV performance, such as diastolic dysfunction.

Impaired tissue Doppler diastolic function in patients with coronary artery disease: relationship to endothelial damage/dysfunction and platelet activation

BACKGROUND

Pulsed tissue Doppler imaging (TDI) allows direct measurement of systolic and diastolic function of the left ventricle. In patients with coronary artery disease (CAD), myocardial ischemia-related impaired diastolic function may be linked to systemic endothelial damage/dysfunction and increased thrombogenesis. We hypothesized relationships between TDI-defined diastolic dysfunction and plasma von Willebrand factor (vWf, marking endothelial damage/dysfunction), soluble P-selectin (sP-sel, reflecting platelet activation), fibrin D dimer (an index of fibrin turnover and thrombogenesis), fibrinogen, and plasma viscosity (PV) in CAD.

METHODS

Conventional 2-dimensional Doppler echocardiography and TDI were performed in 75 stable CAD patients (55 men, 59 +/- 11 years) and 40 age- and sex-matched healthy controls. Peak systolic (Sm), peak early (Em), and late (Am) diastolic mitral annular velocities measured at 4 sites (septal, lateral, inferior, and anterior) were averaged as global systolic and diastolic left ventricular function, respectively. The mean TDI velocities were dichotomized into low and high (below/above median) groups. Plasma vWf, sP-sel, D dimer (enzyme-linked immunosorbent assay), fibrinogen (modified Clauss), and PV levels were measured.

RESULTS

CAD patients had significantly lower Sm, Em, Em/Am ratio, and a higher ratio of early transmitral flow E-velocity over Em (E/Em) when compared with controls (all P < .05). On multivariate analysis, adjusted for age, ejection fraction, and clinical variables, the differences in the group means of vWf, sP-sel, and fibrinogen remained significantly different between the low and high TDI indexes. D-dimer levels were unrelated to any TDI indexes. None of the transmitral flow indexes were independently related to the research indexes.

CONCLUSIONS

In patients with CAD, diastolic dysfunction was closely associated with increased platelet activation and endothelial damage/dysfunction independent of systolic function. TDI-derived indexes are more sensitively related to plasma hemostatic markers than transmitral indexes in middle-aged patients with CAD.

Strain and strain rate imaging: a new clinical approach to quantifying regional myocardial function

On the basis of color Doppler myocardial motion data, 1-dimensional regional natural strain rate and strain curves can now be calculated by comparing local myocardial velocity profiles. Such deformation data sets may be an important, new, and more sensitive approach to quantifying both regional radial and long-axis function of the left or right ventricle in both acquired and congenital heart disease. The normal ranges of regional velocity, strain rate, and strain values have already been determined in both adults and children. This review will focus both on the potential clinical applications of these new ultrasound-based deformation parameters and the current limitations inherent in implementing the technique in everyday practice.

Noninvasive assessment of hemodynamic parameters in experimental stenosis of the ascending aorta

We sought to noninvasively evaluate left ventricular (LV) function after cardiac hypertrophy induced by experimental stenosis of the ascending aorta. Male Wistar rats (70-90 g) underwent ascending aorta constriction by the surgical placement of a titanium clip (n=5) or sham operation (n=6). High-resolution bidimensional, pulsed-wave Doppler (PWD) and pulsed-wave tissue Doppler imaging (TDI) were performed 22 weeks after surgery. PWD was used to obtain mitral flow velocities, and TDI was used to obtain velocities along the septal mitral annulus and LV posterior wall. Clip placement produced myocardial hypertrophy with decreased systolic myocardial peak velocity in both the long and short axes. Increased myocardial mass, that is, posterior wall and septal thickness, was indicative of ventricular remodeling. Diastolic dysfunction was observed, with an increased early to late ratio of mitral velocities and increased left atrium dimension, consistent with a left ventricular restrictive filling pattern.

Color-coded tissue Doppler assessment of the effects of acute ischemia on regional left ventricular function: comparison with sonomicrometry

Echocardiographic assessment of regional left ventricular (LV) function usually consists of subjective visual inspection of endocardial movement and wall thickening. Color-coded tissue Doppler (TD) is a potential means to quantify regional LV function more objectively. Accordingly, in this study, color-coded TD was used to assess the regional effects of acute ischemia in an open-chest canine model of coronary occlusion, with implanted sonomicrometry length crystals as a standard of reference. Eight dogs were studied during baseline conditions and during left anterior descending coronary artery occlusion. Midventricular short-axis images were used to guide the color TD M-mode cursor through circumflex (septal) and left anterior descending (anterolateral) perfusion zones. Off-line conversion of endocardial time-velocity maps was performed. Peak systolic endocardial velocity by TD decreased from 4.4 +/- 1.4 cm/s to 1.8 +/- 1.5 cm/s with coronary occlusion (P < .05 versus baseline). Similar significant decreases in calculated systolic velocity by sonomicrometry occurred with ischemia from 11.1 +/- 3.8 mm/s to 8.2 +/- 1.2 mm/s (P < .05 versus baseline). Peak systolic velocity by TD was inversely correlated with end-systolic length by sonomicrometry as a measure of regional function (r = -0.77, P < .001). Time to peak systolic velocity increased with ischemia from 154 +/- 60 ms to 286 +/- 67 ms by TD and 200 +/- 60 ms to 320 +/- 30 ms by sonomicrometry (P < .05 versus baseline). The delay in time to peak systolic velocity by TD and sonomicrometry were correlated (r = 0.75, P < .001). In conclusion, color-coded TD echocardiography has the potential to quantify regional LV function during coronary ischemia.