Myocardial Tissue Doppler Research Articles

Mechanisms of Exercise-Induced Pulmonary Hypertension in Patients With Cardiac Septal Defects

The objective of this study was to investigate mechanisms of exercise-induced pulmonary hypertension in patients with congenital cardiac septal defects. This was a randomized, placebo controlled, crossover drug trial in a single national pediatric cardiology centre that performs congenital cardiac defect surgery. There were 14 patients with cardiac septal defects and known exercise-induced pulmonary hypertension. The intervention consisted of 50 mg oral sildenafil versus placebo. Measurements included supine bicycle exercise echocardiography and oxygen uptake. The outcome measure was right-ventricular systolic pressure as estimated by Doppler tracings of tricuspid regurgitant jet as well as systolic and diastolic longitudinal myocardial velocities by color tissue Doppler echocardiography. Sildenafil did not change exercise right-ventricular systolic pressure during exercise; however, decreased systemic systolic pressure was seen. Enhanced biventricular longitudinal function with sildenafil compared with placebo was indicated by greater tissue Doppler velocities and displacement measurements during exercise. Finally, a less steep increase of right-ventricular pressure during exercise was associated with greater left-ventricular diastolic myocardial tissue Doppler velocity. Exercise-induced pulmonary hypertension in cardiac septal defects does not seem to have a pulmonary vasoconstrictive component, but it may be related to left-ventricular filling pressure. Furthermore, sildenafil improved biventricular systolic performance in this patient group, possibly related to decreased systemic afterload.

Fetal myocardial tissue Doppler indices before birth physiologically change in proportion to body size adjusted for gestational age in low-risk term pregnancies

BackgroundFew studies have investigated the relationship between myocardial tissue Doppler parameters and fetal size adjusted for gestational age and its trend has been controversial. AimsTo investigate fetal cardiac function before birth using tissue Doppler imaging (TDI: indicated by the prime symbol (′)) in low-risk term pregnancies by comparing the TDI parameters with gestational age-specific birth weight percentiles and z scores.Study design and measurementsInterventricular septum, left and right ventricular myocardial peak early diastolic (E′), late diastolic (A′) and systolic (S′) velocities, E′/A′ ratios, myocardial performance index (MPI′) and umbilical artery pulsatility index were measured within three days before birth in 76 low-risk term pregnancies, including appropriate for gestational age (AGA, n=50), small for gestational age (SGA, n=10), and large for gestational age (LGA, n=16) subjects. ResultsMyocardial peak velocities showed higher in the LGA and lower in the SGA compared with the AGA group, and All S′ positively correlated with birth weight (r=0.51–0.57). All z scores of S′ demonstrated a positive correlation with birth weight z score (Spearman r=0.45–0.53). MPI′ was significantly higher in the SGA and lower in the LGA compared with the AGA group. All MPI′ negatively correlated with birth weight (r=−0.55 to −0.65). All z scores of MPI′ showed a negative correlation with birth weight z score (Spearman r=−0.40 to −0.56). ConclusionsFetal myocardial peak velocities and MPI′ physiologically changed in proportion to body size adjusted for gestational age in low-risk term pregnancies.

Abstract 8915: Utility of Transmural Myocardial Strain Profile to Predict Early Left Ventricular Dysfunction in Patients with Duchenne Muscular Dystrophy

Background: Myocardial damage in Duchenne muscular dystrophy (DMD) leads to lethal outcome. Therefore, early detection of myocardial changes in DMD is important because earlier treatment might help to prevent the development of myocardial fibrosis. Transmural myocardial strain distribution can be obtained as a form of transmural strain profile using myocardial tissue Doppler strain imaging. Accordingly, the aim of this study was to test the hypothesis that transmural strain profile (TMSP) analysis can predict future left ventricular (LV) dysfunction in DMD patients with preserved ejection fraction (EF). Methods: We studied 57 consecutive DMD patients who did not have LV wall motion abnormality; EF 60±7% (all ≥ 55%), aged 11±3 years. Echocardiography was performed at baseline and 1-year follow-up. TMSP was evaluated in the posterior wall from mid-LV short-axis view (Aplio-XG Toshiba Corp.). Results: Thirty-seven patients (65%) had normal TMSP pattern (Group 1), and the remaining 20 patients (35%) were classified as TMSP with a notch (Group 2). The peak strain value in the posterior wall and EF were similar between two groups. Of 20 patients in Group 2, 8 patients (40%) had wall motion abnormality in the posterior wall at 1-year follow-up. On the other hand, no patient in Group 1 had wall motion abnormality at 1-year follow-up (p<0.001 vs. Group 2). Conclusions: Subclinical LV dysfunction can be detected with TMSP in DMD patients who do not have wall motion abnormalities by conventional echocardiography. TMSP with notch was useful at evaluating early subtle changes in DMD patients, and may be useful for predicting future LV dysfunction.

Impaired Diastolic Function and Disruption of the Force-Frequency Relationship in the Right Ventricle of Newborn Pigs Resuscitated with 100% Oxygen

Background: Resuscitation with 100% oxygen increases oxidative stress and is detrimental for organ function. Objective: To study the effects of resuscitation with 100% oxygen compared to room-air on myocardial function. Methods: Twenty-eight newborn pigs underwent global hypoxia (8% oxygen/N₂) until base excess reached –20 mmol/l. The animals were randomized into two groups and resuscitated with either 100% or room air for 30 min. Myocardial tissue Doppler velocities and acceleration of the mitral and tricuspid valve annuli during systole and diastole were assessed before global hypoxia and after resuscitation together with troponin I. Results: Peak early diastolic velocity (E′) and acceleration (pEac) in the septum and pEac in the lateral tricuspid valve annulus were lower after resuscitation with 100% oxygen, suggesting impaired diastolic relaxation in the right ventricle. Lower systolic velocities and acceleration in the right ventricle relative to heart rate indicate disruption of the right ventricular force-frequency relationship after resuscitation with 100% oxygen. Troponins were higher in the 100% oxygen group, suggesting increased myocardial damage in this group. Conclusion: Resuscitation with 100% oxygen compared to room air induces diastolic dysfunction, disrupts the systolic force-frequency relationship and increases myocardial damage in the newborn pig.

Subclinical echocardiographic abnormalities in phenotype-negative carriers of myosin-binding protein C3 gene mutation for hypertrophic cardiomyopathy

Early diastolic myocardial tissue Doppler velocities have reported to be reduced in mutation-positive patients with hypertrophic cardiomyopathy (HCM) in some studies even in the absence of left ventricular hypertrophy (LVH). Strain is a sensitive tool in detecting early systolic abnormalities in patients with HCM. Our goal is to examine novel echocardiographic characteristics of phenotype-negative carriers for a known sarcomeric gene mutation for HCM. We evaluated 41 consecutive subjects with a known myosin-binding protein C3 (MYBPC3) mutation (c.3330+2T>G). Subjects who were mutation positive without LVH (G+/LVH-, n = 35) were compared with healthy controls (n = 30) regarding tissue Doppler and segmental longitudinal strain measures. The G+/LVH- group was similar to the healthy controls with respect to chamber size, left ventricular mass index, and most diastolic filling parameters, including tissue Doppler-derived early diastolic annular velocities. Global longitudinal strain was similar for both groups (20.3 ± 2.1 vs 19.8 ± 1.8, P = .36), although regional segment analysis showed a notable reduction in the basal septum (16.8 ± 3.1 vs 19.0 ± 4.0%, P = .02) and increase in the basal posterior (22.5 ± 5.2 vs 17.9 ± 5.2, P = .001) as well as mid posterior (21.8 ± 4.7 vs 18.2 ± 3.0, P = .001) walls. In our cohort of phenotype-negative carriers of a specific MYBPC3 mutation, there were minimal differences in conventional 2-dimensional, Doppler, and speckle-tracking-derived parameters of systolic and diastolic function compared with that of healthy subjects. The presence of regional alterations in strain indicative of the presence of underlying subclinical disease requires further validation.

Ratio of Right to Left Ventricular Ejection: A Pilot Study Using Doppler to Detect Interventricular Dyssynchrony

Chronic pulmonary hypertension (cPH) is known to delay maximal right ventricular (RV) deformation, causing mechanical dyssynchrony, which previously has been identified only through the use of myocardial tissue Doppler imaging. However, alterations between RV and left ventricular (LV) ejection should be easily identified during routine echocardiographic examinations. We hypothesized that assessment of differences in ejection fraction between left and right ventricles would be detected using pulsed Doppler. Standard echo and Doppler data were collected from 30 patients without PH (mean age, 53 ± 7 y; mean pulmonary artery systolic pressure [PASP], 31 ± 5 mm Hg) and from 40 patients with cPH (mean age, 53 ± 13 y, P not significant; mean PASP, 82 ± 24 mm Hg, P<0.00001). Temporal differences in the ejection of both ventricles were measured as the ratio of total duration of RV to LV outflow tract (RVOT and LVOT) pulsed Doppler signals. A ratio (<0.99) of RVOT to LVOT total duration of ejection was found not only to be the best Doppler parameter to identify an abnormal pulmonary artery systolic pressure, with a 90% sensitivity and 100% specificity (area under the curve 0.958, P = 0.0001), but also identified differences in the temporal ejection between the 2 ventricles, or dyssynchrony, as a result of cPH. The ratio of pulsed Doppler RV to LV total duration of ejection is easily obtainable and appears useful in identifying the presence of interventricular dyssynchrony in cPH patients. A prospective study is now required to determine if this Doppler ratio can identify minute changes in the ejection of both ventricles as a result of changes in disease status or response to PH therapy.

Effects of myocardial ischaemia on left ventricular untwist and filling pressure

ObjectiveTo link ischaemia, left ventricular (LV) untwisting and changes in filling pressure during dobutamine stress echocardiography (DSE).DesignCross-sectional study at rest and at peak dobutamine stress.SettingAcademic medical centre.PatientsPatients who had undergone...

Myocardial tissue Doppler velocities in fetuses with hypoplastic left heart syndrome

Background:Tissue Doppler Imaging (TDI) is a sensitive index of myocardial function. Its role in the fetus has not been extensively evaluated.Objective:To compare myocardial tissue Doppler velocities in fetuses with hypoplastic left heart syndrome (HLHS) to those of normal fetuses (matched for gestational age.)Methods:Cross-sectional retrospective study conducted at 2 large perinatal centers (2003-2007). Fetuses with HLHS (n = 13) were compared with normal fetuses (n = 207) in 5 gestational age groups. TDI data included peak systolic (s’), peak early (e’), and late diastolic velocities (a’). Linear regression was used to compare TDI parameters in fetuses with HLHS to normal fetuses matched for gestational age.Results:Fetuses with HLHS had significantly reduced lateral tricuspid annular e’ as compared to normal fetuses. Both normal fetuses and those with HLHS had linear increase in TDI velocities with advancing gestational age.Conclusions:TDI velocities are abnormal in fetuses with HLHS. TDI can be useful in serial follow-up of cardiac function in fetuses with HLHS.

Myocardial tissue doppler imaging in studying of change in the longitudinal right ventricular function in patients with chronic obstructive pulmonary disease

The obstructive of paper was to study and match clinical symptoms of chronic obstructive pulmonary disease, laboratory and instrumental analyses data, and data obtained from myocardial Tissue Doppler Imaging. Sixty four patients four patients with chronic obstructive pulmonary disease were examined. It was discovered that information obtained through myocardial Tissue Doppler Imaging is in fact early evidence of pulmonary heart disease available at the pre-clinical stage (functional changes are observed before clinical symptoms).

Gestational age‐ and estimated fetal weight‐adjusted reference ranges for myocardial tissue Doppler indices at 24–41 weeks' gestation

To construct gestational age (GA)- and estimated fetal weight (EFW)-adjusted reference ranges for tissue Doppler cardiac function parameters from 24 to 41 weeks' gestation. This was a prospective cross-sectional observational study involving 213 singleton pregnancies between 24 and 41 weeks' gestation. Myocardial peak velocities and myocardial performance index (MPI') were measured by tissue Doppler ultrasonography (values indicated by 'prime') in the left and right annulus and interventricular septum. Left and right atrioventricular parameters were also measured by conventional Doppler and ratios between the values found by the two methods calculated. Regression analysis was used to determine GA- and EFW-adjusted reference ranges and to construct nomograms for tissue Doppler parameters. All myocardial peak velocities, left and right E'/A' and left MPI' showed a progressive increase with GA. In contrast, left and right E/E' showed a progressive decline. Septal E'/A', and right and septal MPI' remained constant. Myocardial peak velocities showed a progressive increase with increasing fetal weight. Normal data of fetal myocardial peak velocities, their ratios and MPI' by tissue Doppler adjusted by GA and EFW are provided. The reported reference values may be useful in research or clinical studies and can be used in fetuses with intrauterine growth restriction.

OP08.01: Assessment of fetal myocardial dynamics by using myocardial tissue Doppler velocity gradient

OP08.01: Assessment of fetal myocardial dynamics by using myocardial tissue Doppler velocity gradient

Study on the clinical significance and fetal cardiac function of fetuses with intracardiac hyperechogenic foci using fetal echocardiography

Objective To evaluate the clinical significance and cardiac function of fetuses with intracardiac hyperechogenic focus(ICEF) by fetal echocardiography. Methods Fetal echocardiograms were performed on 1291 fetuses for evaluation of fetal heart structures and rhythms. Echocardiographic characteristics of ICEF were investigated. Fetal systolic and diastolic functions of 399 fetuses with an isolated ICEF were compared with 128 normal fetuses using conventional two-dimensional, M-mode, pulsed Doppler echocardiography and myocardial Doppler tissue imaging(DTI). Results The prevalence of ICEF was 34. 7% (448/1291). Twenty-four(5.4%) cases were found with cardiovascular malformations. There was 1 (0.22%) case of ICEF fetus associated with chromosomal abnormality (trisomy 21 ). Comprehensive fetal echocardiographic data analysis showed no significant differences in heart dimensions, global cardiac functions,and myocardial performances in the two groups( P ＞0.05). Conclusions An isolated ICEF in the fetal heart is not associated with increased risk for chromosome abnormalities. Fetuses with ICEF do not indicate impaired left ventricular systolic or diastolic function, therefore having no hemodynamic significance. Key words: Echocardiography; Fetus; Intracardiac hyperechogenic focus

Reproducibility of Doppler measures of ventricular function during maximal upright cycling

Echocardiographic measures of ventricular function during exercise may prove useful in assessing myocardial health. This study examined test-retest reproducibility of measurements of Doppler mitral flow velocity (E-wave) and myocardial tissue Doppler imaging (E'-, S-waves) during a progressive maximal upright cycle test in 12 healthy lean adolescent males. Measurements were taken as subjects pedalled to exhaustion with 35 watt work increments in two separate trials. We observed no significant differences in mean values at rest, submaximal (70 watts) exercise, or maximal exercise for all three variables. Coefficients of variation at maximal exercise were 5.3%, 7.4%, and 8.1% for mitral E, tissue Doppler-S, and tissue Doppler-E', respectively. These findings indicated acceptable levels of reproducibility of Doppler ultrasound techniques for assessing ventricular systolic and diastolic functional response to maximal exercise in young lean male subjects.

Myocardial Tissue Doppler Velocity Imaging in Children: Comparative Study between Two Ultrasound Systems

The investigators compared pulsed-wave tissue Doppler (PWTD) and color tissue Doppler (CTD) ventricular tissue velocities obtained using Vivid 7 (GE) and iE33 (Philips) ultrasound systems within a 30-minute time frame and examined interobserver and intraobserver variability. Longitudinal PWTD and CTD images were prospectively acquired in 49 children from the base of the right and left ventricular free wall and septum and stored for offline analysis. Intraobserver and interobserver coefficients of variation for PWTD velocities ranged from 4% to 6% and 5% to 10% for GE and from 1% to 10% and 2% to 14% for Philips, respectively. Intraobserver and interobserver coefficients of variation for CTD velocities ranged from 4% to 15% and 6% to 24% for GE and from 6% to 19% and 7% to 25% for Philips, respectively. Mean biases between the two systems for PWTD velocities, expressed as percentage differences, were around 0%, with the narrowest limits of agreement for systolic velocities at the septal annulus and the widest limits of agreement for early diastolic velocities at the lateral tricuspid valve annulus, respectively. Peak CTD-derived velocities were significantly and consistently lower for Philips compared with GE. Agreement between GE-derived and Philips-derived PWTD velocities was reasonable, whereas CTD-derived velocities differed substantially.

Evaluation of the myocardial performance index and tissue doppler imaging by comparison to near-simultaneous catheter measurements in pediatric cardiac transplant patients

Parameters derived from Doppler echocardiography, such as the myocardial performance index (MPI) and the ratio of peak velocity of early diastolic prograde flow (E) across the atrioventricular valve (AVV) divided by the peak velocity of early diastolic tissue motion at the AVV annulus (E') (E:E' ratio), are routinely used to assess ventricular function. However, they have not been compared with measurements obtained by cardiac catheterization (CC) in children. We prospectively studied post-cardiac transplant children undergoing CC with near-simultaneous echocardiographic imaging for MPI and E:E'. CC data included right atrial pressure (RAp), pulmonary artery wedge pressure (PAWp) and cardiac index (CI). One investigator, who was blinded to the CC data, measured right ventricular (RV) and left ventricular (LV) MPI and E:E' offline. Correlations between echocardiographic and catheter measurements were calculated. Receiver-operating-characteristics (ROC) curves were created to evaluate the utility of echocardiographic measurements that exhibited statistically significant correlations with CC measurements. Twenty-four patients (age range 0.8 to 21 years) underwent 142 CCs during the study period. Of the 12 correlations studied, 3 met statistical significance (p < 0.05) (RV E:E' vs RAp, RV E:E' vs PAWp and LV MPI vs CI). The ROC areas for these correlations were 0.38, 0.42 and 0.68, respectively. There were no cut-off points where both the sensitivity and specificity for any measurement were >0.80. Our data suggest that MPI and E:E' are poor predictors of simultaneously obtained, catheter-derived hemodynamic parameters in post-transplant children. These limitations should be carefully considered before ascribing diagnostic value to these measurements.

Usefulness of myocardial tissue Doppler vs conventional echocardiography in the evaluation of cardiac dysfunction in early-onset intrauterine growth restriction

To evaluate cardiac function by tissue Doppler imaging vs conventional echocardiography in intrauterine growth restriction. A prospective study in 25 intrauterine growth restriction, and in 50 normally grown fetuses between 24 and 34 weeks. Conventional echocardiography (E/A ratios, outflow tract velocities and myocardial performance index), and tissue Doppler (myocardial peak velocities, E'/A' ratios and myocardial performance index') measurements were performed. With conventional echocardiography, intrauterine growth restriction fetuses showed an increase in left myocardial performance index but similar values of E/A ratios, outflow tract velocities and right myocardial performance index as compared with controls. Tissue Doppler imaging demonstrated that intrauterine growth restriction fetuses had significantly lower systolic and diastolic myocardial velocities in mitral and tricuspid annulus, higher mitral E'/A' ratio and higher mitral, tricuspid and septal myocardial performance index' values. Tissue Doppler imaging demonstrated the presence of both systolic and diastolic cardiac dysfunction in intrauterine growth restriction. Tissue Doppler imaging may constitute a more sensitive tool than conventional echocardiography to evaluate cardiac dysfunction in intrauterine growth restriction.

Feasibility of Using Tissue Doppler Velocities in Stress Echo during Upright Bicycle Exercise

There are several studies on myocardial tissue Doppler velocities during dobutamine stress, but few studies on the same parameters during bicycle exercise. We wanted to examine how sample sites affected velocities, beat-to-beat variability and segments eligible for analysis. Twenty patients with normal coronary arteries were included in the study. Echocardiograms were obtained at rest and at peak exercise on the exercise bike and were analyzed off line by two independent raters. Tissue velocities decreased from base to apex. Mean difference between the raters was-0.02 cm/sec at rest and 0.45 cm/sec during exercise. Peak-to-peak variability was lowest in the mitral ring during rest (10-14%) and increased at peak exercise (15-21%). The proportion of segments eligible for analysis was 84% in the septum and 67% in the anterior wall during exercise. Thus, in patients with normal coronary arteries, tissue Doppler velocities decrease from base toward the apex during bicycle exercise. Interrater agreement is reduced during exercise and beat-to-beat variability is lowest in the mitral ring.

Selective right ventricular impairment following coronary artery bypass graft surgery

The right ventricle (RV) may be selectively impaired following coronary artery bypass graft (CABG) surgery. We tested this hypothesis in two study parts: a prospective cohort undergoing CABG, and a retrospective cross-sectional cohort of heart-failure patients with and without a history of CABG. In the prospective study, 20 patients undergoing CABG had echocardiography prior to surgery and 3 months postoperatively. In the retrospective study, 101 patients with established heart failure underwent echocardiography, 40 of whom had undergone previous CABG and 61 of whom had not. Myocardial tissue Doppler velocities were used as a measure of left and right ventricular function. To adjust for varying degrees of overall cardiac impairment, we calculated the ratio between the velocities of the RV and left ventricle (LV). In the prospective study, there was a significant fall in RV:LV ratio following CABG surgery. For S', the ratio fell from 2.27 to 1.13 (50%, p<0.0001), for E' from 1.49 to 0.94 (37%, p<0.0001) and for A' from 1.66 to 1.05 (37%, p<0.0001). In the retrospective study, the RV:LV ratio was lower in the CABG group compared with the non-CABG group for S' (by 32%, p<0.001), E' (by 39%, p<0.001) and A' (by 37%, p<0.001). In the retrospective study, even when the CABG patients were compared with the ischaemic aetiology heart-failure patients without CABG, a similar relative impairment was seen: 25% in S' (p<0.001), 34% in E' (p<0.001) and by 38% in A' (p<0.002). Both prospectively and cross-sectionally, there is evidence of substantial, selective right ventricular impairment following CABG. These features cannot be explained simply by some general feature of ischaemia and, therefore, must be a consequence of surgery.

Regional functions of the left ventricle in patients with coronary slow flow and the effects of nebivolol

Microvascular and endothelial dysfunction have been implicated for coronary slow flow (CSF). Nebivolol, besides its beta-receptor blocking activity, causes an endothelium-dependent vasodilatation through increased nitric oxide release. This study included 27 patients with CSF and 27 subjects with normal coronary arteries. Segmental functions of the left ventricle (LV) were assessed using myocardial tissue Doppler velocities before and 3 months after treatment with nebivolol 5 mg/day. Compared with the control group, mitral deceleration time (DT) was significantly longer, and E/A ratio, systolic velocity of lateral mitral annulus (S(m)) and regional myocardial peak systolic and early diastolic velocities (V( s), V(d)) were significantly lower in patients with CSF. The reason for coronary angiography was typical angina in 21 (77.8%) and positive treadmill test in six (22.2%) CSF patients. There were significant correlations between presence of CSF in left anterior descending artery (LAD) with S( m) (r =-0.404, p =0.002) and V(s) in anterior (r =-0.531, p < 0.001 ) and lateral (r =-0.495, p < 0.001 ) segments and between presence of CSF in RCA and V(s) in posterior segments (r =-0.501, p < 0.001). Treatment with nebivolol significantly decreased blood pressures (128.5+/-12.5/82.5+/-8.8 to 119.8+/- 12.6/76.4+/- 7.4 mmHg, p < 0.001), DT (252.3+/-53.6 to 222.0+/-41.0 ms, p < 0.001 ) and IVRT (115.7+/-19.9 to 103.3+/-17.0 ms, p <0.001), and increased exercise capacity (8.7+/-1.3 to 10.4+/-0.9 METs, p < 0.001), E/A ratio (0.87+/-0.26 to 1.08+/-0.23, p <0.001) and myocardial velocities (p < 0.001). All the patients were free of angina after treatment. Patients with CSF had impaired diastolic and regional LV functions. Nebivolol may therefore be useful in improving angina, exercise capacity and LV functions in patients with CSF.

Asymptomatic Carriers of MYBPC3 Gene Mutation for Hypertrophic Cardiomyopathy Are Characterized by Normal Early Diastolic Tissue Doppler Velocities and Longitudinal Strain

Background: Early diastolic myocardial tissue Doppler (TD) velocities (Ea) may be reduced in mutation positive patients without left ventricular hypertrophy (LVH) as a marker of subclinical disease. Strain is considered a sensitive tool in the detection of early systolic abnormalities in patients with known hypertrophic cardiomyopathy. We examined echocardiographic characteristics of asymptomatic carriers for a known MYBPC3 gene mutation for hypertrophic cardiomyopathy (HCM), including tissue Doppler and strain based indices.