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Evaluation of subendocardial ischemia by strain Doppler echocardiography in patients with left ventricular outflow tract obstruction.
No full textBackground: The purpose of the present study was to assess the subendocardial wall function using tissue Doppler imaging (TDI) and strain rate imaging (SRI) in patients with congenital left ventricular outflow (LVOT) obstruction.
Methods: We studied with TDI and SRI 19 pts aged 11-31 years with congenital aortic stenosis (valvular, 12 pts; subvalvular, 6pts; supravalvular, 1pt). 13 age-and sex-matched subjects with no signs of heart disease were selected as normal controls (CTR). On the basis of LVOT pressure gradient, pts were distinguished in two groups: group 1 (10 pts), gradient < 50mmHg; group 2 (9 pts), gradient 50 mmHg. TDI wall velocities during systole (Sw), early relaxation (Ew) and atrial systole (Aw) were measured in both groups in the apical four chambers views. Peak strain (e) and strain rate (SR) were measured during isovolumic contraction (IC), systole (S), isovolumic relaxation (IR), early diastole (E) and late diastole (A) in endocardium (End), myocardium (Myo) and epicardium (Epi) in the same views.
Results: TDI measurements of the three myocardial layers showed no statistically significant difference among velocities in both pts groups although there was a trend for End velocities to be higher than those of Epi. There was a significant difference in strain and strain rate between the myocardial layers for both isovolumic contraction and relaxation (End-e -38.1 +/- 12.7%, Myo-e -21.7 +/- 8.9%, Epi-e -10.8 +/- 5.5% during IC; End-e 31.9 +/- 11.3%, Myo-e 20.1 +/- 6.3%, Epi-e 10.4 +/- 4.9% during IR; End-SR -2.9 +/- 1.7 sec-1, Myo-SR -1.7 +/- 0.9 sec-1, Epi-SR -0.8 +/- 0.5 sec-1 during IC; End-SR 1.9 +/- 1.3 sec-1, Myo-SR 1.1 +/- 0.3 sec-1, Epi-SR 0.6 +/- 0.5 sec-1 during IR). There was a significant correlation between endocardial strain rate (during IC) and LVOT pressure gradients (r=0.69, p<0.005). Compared to group 1, group 2 pts showed a significant decrease in endocardial strain and strain rate for both isovolumic contraction and relaxation (p<0.001).
Conclusion: Strain and strain rate echocardiography provide a unique insight in evaluating subendocardial wall dysfunction in pts with significant LVOT obstruction
Transesophageal echocardiography with tissue Doppler imaging in the assessment of global and regional systolic and diastolic right ventricular function in atrial septal defects.
No full textBackground. Evaluation of global and regional right ventricular (RV) systolic and diastolic function in atrial septal defects (ASD) is still a challenging post-surgical clinical problem, especially in adult patients (pts) We investigated whether high frame rate tissue Doppler imaging (TDI, Toshiba corp.) may provide quantitative assessment of RV function in ASD pts.
Methods. Twenty-three pts with ostium secundum ASD, aged 25±9 years, were studied with transesophageal echocardiography. Twelve pts underwent corrective surgery. 11 subjects with no signs of heart disease were used as a control group. ASD pts were classified in 3 groups according to 2D/color Doppler defect and shunt size (group “1” large, group “2” medium, group “3” small). Peak mean systolic (Sw) and diastolic (Ew, Aw) wall velocities were acquired from the 4-chamber view in the myocardia [septum (IVS) and free wall (FW)]. TDI wall velocities during systole (Sa), early relaxation (Ea) and atrial systole (Aa) were also measured in the tricuspid annulus. Satisfactory TDI data could be obtained in all pts at end expiration, independent of quality of RV wall motion.
Results. Compared to controls, group “1” pts had lower mean FW velocities (Sw= 5.5±1.9 vs 8.3±2.1 cm/s – p<0.005 –; Ew=5.8±1.9 vs 9.4±2.2 cm/s – p< 0.001 –; Aw=3.5±1.4 vs 3.6±1.8 cm/s – p=NS –) and lower annulus velocities both in systole and diastole (Sa =5.3±1.3 vs 8.9±1.3 cm/s – p<0.001 – ; Ea = 6.2±2.4 vs 13.3±2.4 cm/s – p< 0.001 – ; Aa = 7.8±2.2 vs 7.1±2.3 cm/s – p=NS – ). Also, group “1” pts had lower mean FW Sw and Ew velocities compared to IVS wall velocities (p < 0.005). Group “2” pts had preserved systolic velocities but decreased regional and annular early diastolic velocities suggesting impaired relaxation (Ea/Aa 0.87±0.28 vs 1.64±0.31 – p<0.0001 – ). Group “3” pts had preserved systolic and diastolic velocities.
Conclusion. Thus, TDI is useful in evaluating systolic and diastolic RV abnormalities, could corroborate the need of surgery in pts with volume overload, and may aid in monitoring RV function during post-surgical followup
Evaluation of aortic wall mechanics in Marfan syndrome by transesophageal tissue Doppler echocardiography
No full textBackground: It has been described that the presence of aortic dilation is associated with an increased risk of aortic dissection in patients with Marfan disease. The aim of our study was to investigate the value of combined thoracic aorta dilation and decreased aortic elastic properties in assessing the severity of aortic disease in patients with Marfan syndrome.
Methods: Sixteen patients (pts) with Marfan syndrome (Beighton criteria) aged 13 to 45 years were studied with multiplane transesophageal echocardiography (TEE). 6/16 pts had surgery for aortic dissection. Tissue Doppler imaging (TDI, Toshiba corp.) during TEE was used for the quantification of aortic elastic properties. Eleven age-matched healthy subjects who had normal findings at TEE served as controls. The descending aorta was visualized in a TEE short axis view at the level of the left atrium. TDI tracing displayed accelerated expansion of the aortic wall followed by a slow deceleration, a plateau and then a rapid deceleration into diastole. Acceleration time (AT, msec), maximum wall expansion velocity (Vmax, cm/sec), and wall contraction velocities (cm/sec) were determined.
Results: Descending thoracic aorta dilation (>30mm) was present in 12/16 pts. Vmax values were significantly decreased compared to controls (p 40 mm had a sensitivity of 92%, specificity of 80% and positive predictive value of 77% for predicting aortic dissection.
Conclusion: Our results show that this combined 2D/TDI method is highly predictive for the development of aortic dissection in Marfan syndrome and should suggest aggressive treatment
Assessment of aortic elastic properties by transesophageal strain echocardiography after repair of coarctation of the aorta.
No full textBackground: Increased arterial stiffness may participate in the genesis of hypertension and persistent increases in left ventricular mass after surgical correction of coarctation of the aorta (CoA). The purpose of the present study was to assess the aortic elastic properties using tissue Doppler imaging (TDI) and strain echocardiography in patients (pts) after coartectomy.
Methods: Transesophageal echocardiography with TDI and strain capabilities (Toshiba corp, Tokyo, Japan) was performed in 10 pts aged 12-39 years who had repair of CoA and residual aortic narrowing <30% and who were not hypertensive at rest. 11 age- and sex-matched subjects with no signs of heart disease were selected as normal controls (CTR). Aortic transverse sections were measured at the level of the proximal, distal and coarctation segments. Transverse aortic stiffness was measured by the elastic modulus (Ep) and stiffness index beta () using previously reported formulas. TDI wall velocities during systole (Sw), early relaxation (Ew) and atrial systole (Aw) were measured in transverse views in both groups. Using dedicated software peak systolic strain (ps ) was measured from the resultant deformation curves in the same views.
Results: In the coartectomy pts there was a significant increase of Ep (47.66.5 vs 21.82.9 kPa, p<0.001) and (4.112.51 vs 2.280.65, p<0.005) at the level of the proximal and coarctation segments compared with CTR. At the same level Sw velocities were significantly decreased compared with CTR (4.10.8cm/sec vs 6.90.9cm/sec, p<0.001). There was a significant decrease of ps in the coartectomy pts compared with CTR in the proximal and coarctation segments (71.4% vs 232.5%, p<0.0001). Univariate correlations in the coartectomy group showed significant relationships of and Sw velocities (r=-0.66, p<0.01) and and ps (r=-0.78, p<0.001)
Conclusion: Thus, pts with CoA have increased proximal aortic stiffness and reduced wall velocities and wall strain even after successful repair
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Assessment of right ventricular function by tissue Doppler imaging in patients with chronic obstructive pulmonary disease
No full textBackground. The evaluation of right ventricular function is clinically useful in patients with chronic obstructive pulmonary disease (COPD because the presence of right ventricular failure has prognostic implications. All invasive and non invasive techniques evaluating right ventricular performance have important limitations due to right ventricular complex geometry. The introduction of Doppler measurement of myocardial wall velocities (tissue Doppler imaging, TDI) and the recently developed strain rate (SR) imaging technique have made possible a more adequate assessment of global and regional systolic and diastolic right ventricular function. Our purpose was: 1) to compare TDI/SR parameters with conventional indices evaluating right ventricular function; 2) to assess the correlation among TDI/SR parameters and respiratory function tests . Methods. Twenty-nine patients (age 5313 years) with chronic obstructive pulmonary disease were included in the study. 15 patients had pulmonary artery pressure >35mmHg (group I), 14 patients had pulmonary artery pressure <35mmHg (group II). Sixteen age- and gender-matched healthy subjects who had normal cardiac findings served as controls (group III). Right ventricular ejection fraction (EF), fractional shortening (FS), and tricuspid flow filling parameters (E/A ratio, DT) were determined. Offline analysis of the myocardial velocity data sets was performed using dedicated software (Aplio, Toshiba Corp.). Velocity and strain traces from right ventricular free wall at 3 levels (basal, mid cavity, and apical) were processed from the same wall site in the apical 4-chamber view. Diastolic TDI values (Ew, Aw), peak systolic strain and systolic and diastolic strain rate values were determined. Echocardiographic parameters were evaluated after the respiratory function tests were performed ( FEV1= forced expiratory volume in one second; FEV1/VC = forced expiratory volume in one second / vital capacity; DLCO = single-breath diffusion capacity of the lung for carbon monoxide; DLCO/VA = carbon monoxide diffusion capacity per unit of alveolar volume ) . Results. Measurements of TDI/SR parameters were rapidly obtained with a low inter- and intra-observer variability. Ew/Aw ratio at apical and mid level was lower in Group I and II than in Group III (p<0.005). Peak systolic strain and systolic and diastolic strain rate at apical and mid level were lower in Group I and II than in Group III (p<0.001). Right ventricular EF, FS, E/A ratio, and DT were not different among the three groups. No correlation was found between EF, FS, E/A ratio, DT, and respiratory function tests. A highly significant relationship was shown between peak systolic strain at mid level and DLCO/VA (r=0.67, p<0.001) and peak systolic strain at mid level and FEV1/VC (r=0.69, p<0.001). Conclusion. Thus in COPD patients TDI/SR parameters can determine right ventricular dysfunction that is not shown by conventional echocardiographic indices and is correlated with respiratory function tests
Assessment of right ventricular dysfunction by strain Doppler echocardiography in patients with scleroderma
No full textBackground. Scleroderma is an autoimmune disease that can affect left and right heart function directly through inflammation and fibrosis and indirectly through systemic and pulmonary arterial hypertension. Pulmonary hypertension related to scleroderma is associated with high morbidity and mortality as well as poorer response to therapy. The introduction of Tissue Doppler Imaging (TDI) and Strain Rate Imaging (SRI) techniques have made possible a more adequate assessment of global and regional systolic and diastolic right ventricular function. Our purpose was: 1) to compare TDI/SRI parameters with conventional echocardiographic indices evaluating right ventricular function; 2) to assess the correlation among TDI/SRI parameters and pulmonary artery pressure.
Methods . Twenty-seven patients with scleroderma were studied. 14 patients had pulmonary artery pressure >35mmHg (group I), 13 patients had pulmonary artery pressure <35mmHg (group II). Fifteen healthy subjects who had normal cardiac findings served as controls (group III). Right ventricular ejection fraction (EF), fractional shortening (FS), and tricuspid flow filling parameters (E/A ratio, DT) were determined. Offline analysis of the myocardial velocity data sets was performed using dedicated software. Velocity and strain traces from right ventricular free wall at 3 levels (basal, mid cavity, and apical) were processed from the same wall site in the apical 4-chamber view. Systolic (Sw) and diastolic (Ew, Aw) TDI values, peak systolic strain and systolic and diastolic strain rate values were determined.
Results. Ew/Aw ratio at basal and mid level was lower in Group I and II than in Group III (p<0.005). No significant difference in Ew/Aw ratios was shown between Group I and II. Peak systolic strain and systolic and diastolic strain rate at basal and mid level were lower in Group I than in Group II (p<0.005) and in Group I and II compared to Group III (p<0.001). Right ventricular EF, FS, E/A ratio, and DT were not different among the three groups. No correlation was found between EF, FS, E/A ratio, DT, and pulmonary artery pressure. A significant correlation was also obtained between peak systolic strain rate at basal FW site and pulmonary artery systolic pressure (r=0.69, p<0.005).
Conclusion. In scleroderma patients TDI/SRI parameters can determine right ventricular dysfunction that is not shown by conventional echocardiographic indices and is correlated with pulmonary artery pressur
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