Fetal colour tissue Doppler imaging (cTDI): biventricular reference ranges for the time segments of the cardiac cycle in second and third trimesters of gestation.

PURPOSE: To construct biventricular reference ranges for isovolumic time intervals (isovolumic contraction time, ICT; isovolumic relaxation time, IRT) and ejection time (ET) for colour tissue Doppler imaging (cTDI) between 15 and 37 weeks' in healthy fetuses. METHODS: This was a prospective multicentre cross-sectional study involving 160 singleton pregnancies between 15 and 37 weeks of gestation, using cTDI. ICT, ET, IRT and myocardial performance index (MPI) were analysed offline using a small region of interest (ROI) within the basal part of the right and left ventricular wall immediately distal to the annulus. Regression analysis was used to determine gestational age-adjusted reference ranges and to construct nomograms for cTDI parameters. RESULTS: Right and left ventricular ICT (p = 0.004 and p < 0.001) and ET (p = 0.011 and p = 0.050) increased, whereas IRT (p = 0.862 and p = 0.067) and MPI (p = 0.476 and p = 0.777) remained constant with gestational age. CONCLUSIONS: This is the first study to evaluate fetal isovolumic time intervals in the second and third trimesters of gestation using cTDI. Normal data for fetal isovolumic time intervals and biventricular MPI by colour tissue Doppler imaging are provided. The reference ranges may be useful in research or clinical studies and can be used in fetuses with compromised cardiac function.

Normal reference values of left ventricular strain using three-dimensional speckle tracking echocardiography: results from a multicentre study.

AIMS: Three-dimensional (3D) speckle tracking echocardiography (3DSTE) has been shown to be an accurate and reliable clinical tool for the evaluation of global and regional left ventricular (LV) function through strain analysis, but the absence of normal values has precluded its widespread use in clinical practice. The aim of this prospective multicentre study was to establish normal reference values of LV strain parameters using 3DSTE in a large healthy population. METHODS AND RESULTS: A total of 303 healthy subjects (156 males [51%], between 18 and 82 years of age, ejection fraction [EF] 61 ± 3%), stratified to provide approximately equal proportions of healthy subjects of 18-30, 31-40, 41-50, 51-60, and >60 years of age, underwent 3DSTE. Data were analysed for LV volumes, EF, mass, and global and regional circumferential, longitudinal, radial, and area strain. Significant but small differences between men and women were found for longitudinal and area strains, as well as between different age groups for all LV strain parameters. However, large differences in normal values were observed between different segments, walls, and levels of the LV for radial and longitudinal strains, whereas circumferential and area strains demonstrated generally consistent normal ranges across the LV. CONCLUSIONS: Normal ranges of global and regional LV strain using 3DSTE have been established for clinical use. Differences in the magnitude of LV strain are present between men and women as well as different age groups. Moreover, there are differences between different segments, walls, and levels as part of the functional non-uniformity of the normal LV that necessitates the use of segment-specific normal ranges for radial and longitudinal strains. Circumferential and area strains demonstrate the most consistent normal ranges overall.

Two- and three-dimensional speckle tracking echocardiography: clinical applications and future directions.

Two-dimensional speckle tracking echocardiography (2D STE) is a novel technique of cardiac imaging for quantifying complex cardiac motion based on frame-to-frame tracking of ultrasonic speckles in gray scale 2D images. Two-dimensional STE is a relatively angle independent technology that can measure global and regional strain, strain rate, displacement, and velocity in longitudinal, radial, and circumferential directions. It can also quantify rotational movements such as rotation, twist, and torsion of the myocardium. Two-dimensional STE has been validated against hemodynamics, tissue Doppler, tagged magnetic resonance imaging, and sonomicrometry studies. Two-dimensional STE has been found clinically useful in the assessment of cardiac systolic and diastolic function as well as providing new insights in deciphering cardiac physiology and mechanics in cardiomyopathies, and identifying early subclinical changes in various pathologies. A large number of studies have evaluated the role of 2D STE in predicting response to cardiac resynchronization therapy in patients with severe heart failure. However, the clinical utility of 2D STE in the above mentioned conditions remains controversial because of conflicting reports from different studies. Emerging areas of application include prediction of rejection in heart transplant patients, early detection of cardiotoxicity in patients receiving chemotherapy for cancer, and effect of intracoronary injection of bone marrow stem cells on left ventricular function in patients with acute myocardial infarction. The emerging technique of three-dimensional STE may further extend its clinical usefulness.

Early myocardial deformation changes associated to isolated obesity: a study based on 3D-wall motion tracking analysis.

Obesity is considered as a strong risk factor for cardiovascular morbidity and mortality. 3D-wall motion tracking echocardiography (3D-WMT) provides information regarding different parameters of left ventricular (LV) myocardial deformation. Our aim was to assess the presence of early myocardial deformation abnormalities in nonselected obese children free from other cardiovascular risk factors. Thirty consecutive nonselected obese children and 42 healthy volunteer children were enrolled. None of them had any cardiovascular risk factor. Every subject underwent a 2D-echo examination and a 3D-WMT study. Mean age was 13.9 ± 2.56 and 13.25 ± 2.68 years in the nonobese and obese groups, respectively (59.7% and 40.3% male). Statistically significant differences were found for: interventricular septum thickness, LV posterior wall thickness, LV end-diastolic volume, LV end-systolic volume, left atrium volume, LV mass, and lateral annulus peak velocity. Regarding the results obtained by 3D-WMT assessment, all the evaluated parameters were statistically significantly different between the two groups. When the influence of obesity on the different echocardiographic variables was evaluated by means of multivariate logistic regression analysis, the strongest relationship with obesity was found for LV average circumferential strain (ß-coefficient: 0.74; r(2): 0.55; P: 0.003). Thus, obesity cardiomyopathy is associated not only with structural cardiac changes, but also with myocardial deformation changes. Furthermore, this association occurs as early as in the childhood and it is independent from any other cardiovascular risk factor. The most related parameter to obesity is LV circumferential strain.

Myocardial strain characterization in different left ventricular adaptative responses to high blood pressure: a study based on 3D-wall motion tracking analysis.

BACKGROUND: High blood pressure increases left ventricular (LV) after-load. Furthermore, LV response to that high blood pressure varies among different subjects. Nevertheless, myocardial deformation behavior in these different adaptative responses has not been analyzed until now. METHODS: Prospective study in which 66 consecutive hypertensive patients were enrolled in between May and August 2009. Every patient underwent a standard echocardiographic study and a three-dimensional-wall motion tracking (3D-WMT) study. The patients were classified according to parameters derived from echocardiography in four different groups: normal geometry, concentric remodelling, concentric hypertrophy, and eccentric hypertrophy. RESULTS: Mean age was 68 years (57-74.25; 51.5% male). Comparing the four groups, significant differences were found for the five 3D-WMT-derived parameters. When patients were compared with hypertensive patients with normal geometry, our finding show that: (a) LV average torsion is the only impaired parameter that is found in the LV concentric remodelling group (P < 0.05 vs. group 1); (b) there is a trend for an increase (P = 0.055) in LV average radial strain in the group with concentric hypertrophy and this increase is accompanied by a significant decrease in the remaining studied parameters (P < 0.05); and (c) in the LV eccentric hypertrophy group, there is a significant impairment in all the studied parameters (P < 0.05). CONCLUSIONS: LV adaptative response to hypertension is accompanied by a modification or even impairment, in LV myocardial deformation evaluated by 3D-WMT. This assessment might be useful to detect early and subtle deformation impairments in hypertensive patients and it could help optimize their clinical management.

Quantitative evaluation of regional left ventricular function using three-dimensional speckle tracking echocardiography in patients with and without heart disease.

Although 2-dimensional (2D) speckle tracking echocardiography has been shown to be useful in the assessment of regional left ventricular function, it is limited by the assumption that speckles can be tracked frame-to-frame within the imaging plane, even though the cardiac motion is 3-dimensional (3D). Our goal was to evaluate new 3D-speckle tracking echocardiographic (STE) software by (1) comparing the regional wall motion measurements against 2D-STE images, and (2) testing its ability to identify regional wall motion abnormalities. The 2D images and real-time 3D data sets (Toshiba) obtained from 32 subjects were analyzed to measure segmental radial and longitudinal displacements and rotation, as well as the radial, longitudinal, and circumferential strains. The intertechnique comparisons included regression and Bland-Altman analyses. Additionally, cardiac magnetic resonance images (Siemens 1.5 T) acquired the same day were reviewed by an expert who classified the segments as normal or abnormal. The values of each 3D-STE index were compared between the normal and abnormal segments. The 3D-STE and 2D-STE indexes did not correlate well (r = 0.16 to 0.76) and showed wide limits in intertechnique agreement (2 SD: 5 to 6 mm for displacements, 14 degrees rotation, 17% to 52% strains) despite only minimal biases, indicating that these 2 techniques are not interchangeable. In normal segments, 3D-STE showed greater displacements, reflecting the out-of-plane motion component; smaller SDs, indicating tighter normal ranges; and a gradual decrease in radial and longitudinal displacement and a reversal in rotation from the base to the apex. In the abnormal segments, all 3D-STE indexes were reduced, reaching significance for 5 of 6 indexes. In conclusion, this is the first study to evaluate the new 3D-STE technique for measurement of regional wall motion indexes. Our findings have demonstrated its superiority over 2D-STE.

Quantification of left ventricular volumes using three-dimensional echocardiographic speckle tracking: comparison with MRI.

AIMS: Although the utility of two-dimensional (2D) speckle tracking echocardiography (STE) to quantify left ventricular (LV) volume has been demonstrated, this methodology is limited by foreshortened views, geometric modelling, and the assumption that speckles can be tracked from frame to frame, despite their out of plane motion. To circumvent these limitations, a three-dimensional (3D) speckle tracking algorithm was recently developed. Our goal was to evaluate the accuracy of the new 3D-STE side by side with 2D-STE using cardiac magnetic resonance (CMR) as a reference. METHODS AND RESULTS: Apical two- and four-chamber views (A2C and A4C) and real-time 3D datasets (Toshiba Artida 4D System) obtained in 43 patients with a wide range of LV size and function were analysed to measure LV end-systolic and end-diastolic volumes (ESV and EDV) using 2D and 3D-STE techniques. Short-axis CMR images (Siemens 1.5T scanner) acquired on the same day were analysed to obtain ESV and EDV reference values using the method of disks approximation. Reproducibility of both STE techniques was assessed using repeated measurements. While 2D-STE correlated well with CMR (r: 0.72-0.88), it underestimated LV volumes with relatively large biases (10-30 mL) and wide limits of agreement (SD: 36-51 mL), with A2C-derived measurements being worse than A4C values. The 3D-STE measurements showed higher correlation with CMR (0.87-0.92), and importantly smaller biases (1-16 mL) and narrower limits of agreement (SD: 28-37 mL). In addition, 3D-STE showed lower inter- and intra-observer variability (11-14% and 12-13%), than 2D-STE (16-17% and 12-16%, respectively). CONCLUSION: This is the first study to validate the new 3D-STE technique for LV volume measurements and demonstrate its superior accuracy and reproducibility over previously used 2D-STE technique.