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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Development of a method for calculation of cardiac output using Doppler ultrasound

Diggikar, Amit. January 1999 (has links)
Thesis (M.S.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains viii, 91 p. : ill. (some col.) Includes abstract. Includes bibliographical references (p. 67-69).
2

Determinants of left ventricular mass as measured by Doppler echocardiography in pre-adolescents

Peralta-Huertas, Jose. January 1900 (has links)
Thesis (M.S.)--Brock University, 2005. / Includes bibliographical references (leaves 63-83). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.
3

Determinants of left ventricular mass as measured by Doppler echocardiography in pre-adolescents

Peralta-Huertas, Jose. January 1900 (has links)
Thesis (M.S.)--Brock University, 2005. / Includes bibliographical references (leaves 63-83).
4

Influência do sistema cardiorrespiratório na capacidade funcional de exercício em gestantes com pré-eclâmpsia

Silva, Evelise Guimarães da [UNESP] 27 August 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:35:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-27Bitstream added on 2014-06-13T19:25:00Z : No. of bitstreams: 1 silva_eg_dr_botfm.pdf: 959345 bytes, checksum: 6ef2475219297629c565247c6d4f26c2 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Financiadora de Estudos e Projetos (FINEP) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Avaliar o sistema cardiorrespiratório e sua influência na capacidade funcional de exercício em gestantes com pré-eclâmpsia. Estudo transversal com 50 gestantes portadoras de pré-eclâmpsia e 50 gestantes normotensas, estimado pelo tamanho amostral. Foi realizado espirometria, dopplerecocardiografia e teste de caminhada de seis minutos. Na análise estatística foi usado o teste t e Mann-Whitney para as variáveis com distribuição simétrica e assimétrica, respectivamente, e regressão múltipla linear. As variáveis espirométricas mostraram redução significativa da capacidade vital forçada (L) [3,35 (2,95; 3,74) ν 3,62 (3,31; 3,88) p=0,012], do volume expirado forçado no primeiro segundo (L) [2,85 (2,58; 3,16) ν 3,06 (2,83; 3,27) p=0,034] e da capacidade vital lenta (L) [3,34 (2,87; 3,91) ν 3,65 (3,32; 4,07) p=0,039], no grupo pré-eclâmpsia comparado com o grupo controle, respectivamente. Os valores do diâmetro sistólico (cm) [2,90 (2,7; 3) ν 2,7(2,65; 2,9) p=0,048] e diastólico do ventrículo esquerdo (cm) [4,8 (4,7; 5) ν 4,7 (4,55; 4,8) p=0,016], índice de massa do ventrículo esquerdo (g/m2,7) [48,65 (45,27; 52,12) ν 34,34 (31,57; 38,05) p<0,001], espessura relativa da parede ventricular esquerda (cm) [0,40 (0,38; 0,45) ν 0,34 (0,34; 0,35) p<0,001], volume sistólico (mL) [62,4 (58,57; 67,66) ν 58,19 (55,24; 63,18) p=0,014], tempo de relaxamento isovolumétrico do ventrículo esquerdo (ms) [88 (80; 92) ν 80 (76;84) p<0,001], tempo de desaceleração da onda E (ms) [196 (192;208) ν 192 (188;196) p=0,002] e onda A (cm/s) [64 (54;75) ν 49 (54;54) p<0,001] foram estatisticamente maiores no grupo préeclâmpsia que no controle. Enquanto que a razão E/A foi significativamente menor no grupo pré-eclâmpsia [1,40 (1,21; 1,63) ν 1,72 (1,55; 1,94) p<0,001]. A distância percorrida (m) no teste de caminhada de seis minutos foi significativamente menor... / To evaluate the cardio respiratory system and its influence on the functional exercise capacity of pregnant women with preeclampsia. Cross-sectional trial on 50 pregnant women with preeclampsia and 50 normotensive pregnant women, estimated by sample size. Spirometry, Doppler echocardiography and the six-minute walk test were performed. In statistical analysis, the t test and the Mann-Whitney test were respectively used for variables with symmetrical and asymmetrical distribution, in addition to multiple linear regression. Results: The spirometric variables showed significant reduction in forced vital capacity (L) 3.35 (2.95; 3.74) 3.62 (3.31; 3.88) p=0.012 , in forced expired volume in the first second (L) 2.85 (2.58; 3.16) 3.06 (2.83; 3.27) p=0.034 and in slow vital capacity (L) 3.34 (2.87; 3.91) 3.65 (3.32; 4.07) p=0.039 as compared to the control group, respectively. The values for systolic (cm) 2.90 (2.7; 3) 2.7(2.65; 2.9) p=0.048 and diastolic diameter of the left ventricle (cm) 4.8 (4.7; 5) 4.7 (4.55; 4.8) p=0.016 , mass index of the left ventricle (g/m2,7) 48.65 (45.27; 52.12) 34.34 (31.57; 38.05) p<0.001 , relative thickness of the left ventricular wall (cm) 0.40 (0.38; 0.45) 0.34 (0.34; 0.35) p<0.001 , systolic volume (mL) 62.4 (58.57; 67.66) 58.19 (55.24; 63.18) p=0.014 , isovolumetric relaxation time of the left ventricle (ms) 88 (80;92) 80 (76;84) p<0.001 , deceleration time of the E wave (ms) 196 (192;208) 192 (188;196) p=0.002 and the A wave (cm/s) 64 (54;75) 49 (54;54) p<0.001 were statistically larger in the preeclampsia group than in control while the E/A ratio was significantly smaller in the preeclampsia group 1.40 (1.21; 1.63) 1.72 (1.55; 1.94) p<0.001 . The distance walked (m) in the six-minute walk test was significantly smaller in the preeclampsia group (465± 61) than in the control group (534± 44) p<0.001. Linear multiple regression showed that, in the presence... (Complete abstract click electronic access below)
5

Influência do sistema cardiorrespiratório na capacidade funcional de exercício em gestantes com pré-eclâmpsia /

Silva, Evelise Guimarães da. January 2010 (has links)
Resumo: Avaliar o sistema cardiorrespiratório e sua influência na capacidade funcional de exercício em gestantes com pré-eclâmpsia. Estudo transversal com 50 gestantes portadoras de pré-eclâmpsia e 50 gestantes normotensas, estimado pelo tamanho amostral. Foi realizado espirometria, dopplerecocardiografia e teste de caminhada de seis minutos. Na análise estatística foi usado o teste t e Mann-Whitney para as variáveis com distribuição simétrica e assimétrica, respectivamente, e regressão múltipla linear. As variáveis espirométricas mostraram redução significativa da capacidade vital forçada (L) [3,35 (2,95; 3,74) ν 3,62 (3,31; 3,88) p=0,012], do volume expirado forçado no primeiro segundo (L) [2,85 (2,58; 3,16) ν 3,06 (2,83; 3,27) p=0,034] e da capacidade vital lenta (L) [3,34 (2,87; 3,91) ν 3,65 (3,32; 4,07) p=0,039], no grupo pré-eclâmpsia comparado com o grupo controle, respectivamente. Os valores do diâmetro sistólico (cm) [2,90 (2,7; 3) ν 2,7(2,65; 2,9) p=0,048] e diastólico do ventrículo esquerdo (cm) [4,8 (4,7; 5) ν 4,7 (4,55; 4,8) p=0,016], índice de massa do ventrículo esquerdo (g/m2,7) [48,65 (45,27; 52,12) ν 34,34 (31,57; 38,05) p<0,001], espessura relativa da parede ventricular esquerda (cm) [0,40 (0,38; 0,45) ν 0,34 (0,34; 0,35) p<0,001], volume sistólico (mL) [62,4 (58,57; 67,66) ν 58,19 (55,24; 63,18) p=0,014], tempo de relaxamento isovolumétrico do ventrículo esquerdo (ms) [88 (80; 92) ν 80 (76;84) p<0,001], tempo de desaceleração da onda E (ms) [196 (192;208) ν 192 (188;196) p=0,002] e onda A (cm/s) [64 (54;75) ν 49 (54;54) p<0,001] foram estatisticamente maiores no grupo préeclâmpsia que no controle. Enquanto que a razão E/A foi significativamente menor no grupo pré-eclâmpsia [1,40 (1,21; 1,63) ν 1,72 (1,55; 1,94) p<0,001]. A distância percorrida (m) no teste de caminhada de seis minutos foi significativamente menor... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: To evaluate the cardio respiratory system and its influence on the functional exercise capacity of pregnant women with preeclampsia. Cross-sectional trial on 50 pregnant women with preeclampsia and 50 normotensive pregnant women, estimated by sample size. Spirometry, Doppler echocardiography and the six-minute walk test were performed. In statistical analysis, the t test and the Mann-Whitney test were respectively used for variables with symmetrical and asymmetrical distribution, in addition to multiple linear regression. Results: The spirometric variables showed significant reduction in forced vital capacity (L) 3.35 (2.95; 3.74) 3.62 (3.31; 3.88) p=0.012 , in forced expired volume in the first second (L) 2.85 (2.58; 3.16) 3.06 (2.83; 3.27) p=0.034 and in slow vital capacity (L) 3.34 (2.87; 3.91) 3.65 (3.32; 4.07) p=0.039 as compared to the control group, respectively. The values for systolic (cm) 2.90 (2.7; 3) 2.7(2.65; 2.9) p=0.048 and diastolic diameter of the left ventricle (cm) 4.8 (4.7; 5) 4.7 (4.55; 4.8) p=0.016 , mass index of the left ventricle (g/m2,7) 48.65 (45.27; 52.12) 34.34 (31.57; 38.05) p<0.001 , relative thickness of the left ventricular wall (cm) 0.40 (0.38; 0.45) 0.34 (0.34; 0.35) p<0.001 , systolic volume (mL) 62.4 (58.57; 67.66) 58.19 (55.24; 63.18) p=0.014 , isovolumetric relaxation time of the left ventricle (ms) 88 (80;92) 80 (76;84) p<0.001 , deceleration time of the E wave (ms) 196 (192;208) 192 (188;196) p=0.002 and the A wave (cm/s) 64 (54;75) 49 (54;54) p<0.001 were statistically larger in the preeclampsia group than in control while the E/A ratio was significantly smaller in the preeclampsia group 1.40 (1.21; 1.63) 1.72 (1.55; 1.94) p<0.001 . The distance walked (m) in the six-minute walk test was significantly smaller in the preeclampsia group (465± 61) than in the control group (534± 44) p<0.001. Linear multiple regression showed that, in the presence... (Complete abstract click electronic access below) / Orientador: José Carlos Peraçoli / Coorientador: Beatriz Bojikian Matsubara / Coorientador: Irma de Godoy / Banca: Victor Zuniga Dourado / Banca: Audrey Borghi e Silva / Banca: Vera Therezinha Medeiros Borges / Banca: Silméia Garcia Zanatti Bazan / Doutor
6

Left atrial function in health and disease

Henein, Mark January 2012 (has links)
The Objectives of this thesis are: 1) To study possible atrial interaction in patients with right and left ventricular outflow tract obstruction due to significant pulmonary (PS) and aortic valve stenosis (AS), respectively. 2) To assess left atrial (LA) intrinsic myocardial function and its relationship to indirect measures of left ventricular (LV) filling pressures in patients with paroxysmal atrial fibrillation (PAF). 3) To test the hypothesis that the LA function is affected in patients with pulmonary arterial hypertension (PAH). 4) To test the hypothesis that raised LA pressure as shown by pulmonary capillary wedge pressure (PCWP) correlates with severity of LA intrinsic systolic function. We conducted 4 studies to achieve the objective sabove. Study I Methods: We studied 41 PS patients (age 36±10 year) and 41 AS patients (age 35 ± 12 year) and compared them with 27 controls (age 30 ± 7 year). RV and LV filling were recorded by conventional PW Doppler. Biventricular segmental function was studied using the PW tissue Doppler imaging (TDI) and M mode techniques. Results: The 2 patient groups had similar degree of ventricular outflow tract obstruction. In the pressureoverloaded ventricle, global systolic function was preserved but long axis function was impaired.Patients had higher peak late filling (Awave)and TDI late diastolic (a’) velocities recorded in the disease free ventricles despite having similar peak early filling velocities (E wave), E wave deceleration time and E/e’ ratios were not different from controls (p&gt;0.05 for all). The accentuation of atrial activity (A wave) was moderately correlated with the degree of contra lateral ventricular outflow tract obstruction (p&lt;0.001 for both). Conclusion: In the pressure overloaded ventricle long axis function is more sensitive than global function in revealing myocardial dysfunction. The increased contra lateral atrial systolic activity suggests an evidence for atrial interaction in the form of ‘Cross Talk’. Study II Methods: Twentyfive PAF patients (age 68±7 year, 10 males) with Doppler signs of raised filling pressures were studied using speckle tracking echocardiography and compared with 21 controls. LA segmental longitudinal strain (S), strain rate (SR) and myocardial velocities during atrial systole were measured as were LA longitudinal and transverse diameters. Markers of LV filling pressures were E/A andE/e’. Results: LA longitudinal diameter was larger in patients (5.5±0.6 vs. 4.8±0.6cm,p&lt;0.01) and global LAS and SR were reduced (p&lt;0.05 for both) and correlated with E/A (r=0.52 and r=0.43, p&lt;0.05 for both). LA segmental S and SR were uniformly reduced compared with controls (p&lt;0.05 for all) and also correlated with E/A (p&lt;0.05 for all). LA myocardial velocities (TDI) were highest at the annular level and lowest at the rear in both patients and controls (p&lt;0.01 for all), with the absolute values at each level not different between groups. Myocardial velocities negatively correlated with E/A at the annular level only in patients (septal: r=0.52; lateral: r=0.62, p&lt;0.01 for both). Conclusion: In PAF patients, LA systolic function is suppressed and is directly related to the raised filling pressures. While intrinsic global and segmental function can reproducibly be studied by S and SR, myocardial velocities reflect only regional motion. These findings provide a sound explanation to the known beneficial effect of vasodilators in PAF patients. Study III Methods: We studied LA size and reservoir function in 35 patients (age 63 ± 15 years, 16 male) with idiopathic PAH using speckle tracking echocardiography who also underwent right heart catheterization simultaneously to assess pulmonary artery systolic pressure, and compared them with 27 age and gender normal controls. Results: In PAH patients, LA longitudinal diameter was not different from controls but transverse diameter was reduced (3.0 ± 0.6 vs. 3.7 ± 0.5cm, p&lt;0.001). LA lateral wall strain rate (SR) during LV systole (atrial reservoir function was reduced at annular (p&lt;0.001) and mid cavity (p&lt;0.01) levels as were septal segments (p&lt;0.03, for both) compared to controls. Opposite to controls, the two LA walls responded differently to right heart pressures. Lateral SR inversely correlated with pulmonary artery systolic pressure (PASP) (annular: r=0.45, p&lt;0.005 and midcavity: r=0.43, p&lt;0.01), but not with right atrial pressure (RAP). In contrast, septal SR inversely correlated with RAP (annular: r=0.39, p=0.02 and midcavity: r=0.38, p=0.03) but not with PASP. Conclusion: In patients with PAH, LA reservoir function is significantly impaired showing reduced myocardial strain rate properties. In addition,segmental function differs in their response to raised right heart pressures with the septal wall related to right atrial pressure and lateral wall related to the PASP. These findings suggest an evidence for atrial interaction in PAH, which is likely to have significant impact on LV performance. Study IV Methods: We studied 46 patients, mean age 61 ± 13 years, 17 males, of various etiologies with exertional breathlessness who underwent right heart catheterization and simultaneous transthoracic Doppler echocardiography using spectral, tissue Doppler and speckle tracking echocardiography techniques for assessing LA structure and function. Results: PCWP correlated with direct measurements of LA structure and function: LA volume (r= 0.43, p&lt;0.01), LA global systolic strain rate (r=0.79, p&lt;0.001) and to a lesser extent with LA systolic filling fraction (r=0.52, p&lt;0.001). PCWP also correlated with indirect measures of LA pressure: LV E/A (r=0.66, p&lt;0.001), E wave deceleration time (r=0.54, p&lt;0.001), lateral E/e’ (r=0.49, p&lt;0.001) and LV isovolumic relaxation time (r=0.36, p&lt;0.01). LA strain rate was 78% sensitive and 84% specific in identifying patients with PCWP&gt;15 mmHg, having accurately predicted PCWP in 63% of the cases. Conclusion: PCWP correlates with LA intrinsic systolic function and to a much lesser degree with indirect Doppler measures of raised LV filling pressures. These findings should have significant clinical implications in identifying breathless patients with raised LA pressure.
7

Determinants of left ventricular filling dynamics: alteration in the Doppler-derived transmitral filling profile with progressive impairment of cardiac function in a dog preparation

HAYASHI, H., YOKOTA, M., IWASE, M., NOMURA, H., OGAWA, S., MIYAGUCHI, K. 06 1900 (has links)
名古屋大学博士学位論文 学位の種類 : 医学博士(論文) 学位授与年月日:平成4年7月20日 宮口和彦氏の博士論文として提出された
8

Using tissue Doppler imaging during exercise to assess ventricular function and wall motion in childhood survivors of acute lymphoblastic leukemia

De Souza, Astrid-Marie. January 1900 (has links)
Thesis (M.S.)--University of British Columbia, 2005. / Includes bibliographical references (leaves 33-41). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.
9

Using tissue Doppler imaging during exercise to assess ventricular function and wall motion in childhood survivors of acute lymphoblastic leukemia

De Souza, Astrid-Marie. January 2005 (has links)
Thesis (M. Sc.)--University of British Columbia, 2005. / Includes bibliographical references (leaves 33-41).
10

Association of metabolic and hemodynamic variables during exercise in children.

Hicks, Richard Wayne. January 1987 (has links)
Three investigations were conducted using pulsed Doppler echocardiography (PDE) and oxygen consumption to non-invasively determine the relationship between hemodynamic and metabolic variables from rest through submaximal and maximal exercise in early adolescent males. In the first study, interinvestigator and day-to-day variability of cardiac output measurements at rest and during exercise determined by PDE were analyzed in six junior high school age boys. Four Doppler-derived variables (cardiac output, cardiac index, stroke volume, and stroke index) were not different when calculated by independent investigators and showed the same interinvestigator variability from rest through submaximal and maximal exercise as has been reported at rest in previous validation studies. There was a slight but statistically significant increase in the absolute values of the above hemodynamic variables and simultaneously collected metabolic variables during a second identical test conducted approximately nine days later. A faster adjustment to increasing workrates in the second test could explain this latter finding since supine cycle ergometry is not as familiar an activity as more frequently used modes of exercise testing. It is concluded that hemodynamic measurements using PDE exhibit the same acceptable variability throughout exercise as has been previously demonstrated at rest. In the second study, PDE was used to determine rapid serial measurements of cardiac output during a rapid loading supine cycle ergometer exercise test in twenty-two junior high school age boys. These measurements were compared to simultaneoulsy determined measurements of oxygen consumption. Cardiac output adjusted faster to each new workrate than oxygen consumption. Further analysis of these responses revealed that increases in heart rate (as opposed to stroke volume) were responsible for this rapid adjustment. It is concluded that there is an uncoupling and recoupling of these normally closely related hemodynamic and metabolic variables during the transitional periods between increasing levels of steady-state supine exercise. In the final study, gradual loading and rapid loading supine cycle ergometer protocols were compared in fifteen junior high school age boys. Maximal metabolic measurements and heart rate from each test were not different. Maximal PDE-derived measurements of cardiac output, cardiac index, stroke volume, and stroke index were slightly, but significantly, higher in the gradual loading protocol. It is concluded that a more complete adjustment of cardiac output (reflected by stroke volume) to maximal supine exercise occurs in a more gradual loading protocol than in a rapid loading protocol.

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