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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

Effects of xanthine oxidase inhibitors in pulmonary hypertension associated with chronic lung disease

Liu Shiu Cheong, Patrick January 2019 (has links)
Chronic lung diseases are often complicated with pulmonary hypertension (PH). This can lead to disability and poor prognosis. Oxidative stress has been implicated in the development of PH and right ventricular hypertrophy (RVH).A possible new way to treat lung disease related pulmonary hypertension is allopurinol (a xanthine oxidase inhibitor) which decreases both uric acid and oxidative stress. We hypothesised that allopurinol could regress RVH in patients with pulmonary hypertension associated with chronic lung disease (PH-CLD).In a double-blind, randomised controlled clinical trial, 72 patients with PH-CLD (93% diagnosed with chronic obstructive pulmonary disease and 17% with interstitial lung disease) were randomised to receive either allopurinol 300 mg twice daily or placebo for twelve months. The primary outcome was the mean change in right ventricular mass (RVM) as assessed by cardiac magnetic resonance imaging (CMRI) at twelve months. The secondary outcomes were the change in other cardiac parameters measured by CMRI, St George's Respiratory Questionnaire, Short Form 36, spirometry and six-minute walk test (6MWT).The mean age was 71 years, the mean FEV1 was 60% with mean resting SaO2 of 96%. After 12 months, there was no significant change in RVM. There were also no significant changes in other cardiac parameters measured on CMRI, quality of life questionnaires, spirometry and 6MWT. Post-hoc subgroup analysis showed that allopurinol reduced RVM (allopurinol -6.16 g vs placebo 0.75 g, p = 0.02) in COPD patients with more severe airflow limitation. Patients with higher NT-proBNP (> 489 pg/ml) had a greater improvement in left ventricular ejection fraction with allopurinol 5.12 vs placebo -1.62, p = 0.02.In summary, allopurinol had no overall impact but reduced RV mass in COPD patients with more severe airflow limitation. Further studies are warranted to assess the longer term impact of allopurinol in more severe COPD.
2

Role of Strain Imaging in Right Heart Disease: A Comprehensive Review

Kannan, Arun, Poongkunran, Chithra, Jayaraj, Mahendran, Janardhanan, Rajesh January 2014 (has links)
Advances in the imaging techniques of the heart have fueled the interest in understanding of right heart pathology. Recently, speckle tracking echocardiography has shown to aid in understanding various right heart diseases and better management. Its role is well established in diagnosing right heart failure, pulmonary artery hypertension, arrhythmogenic right ventricular dysplasia and congenital heart disease. We review the basic mechanics of speckle tracking and analyze its role in various right heart conditions.
3

Avaliação ecocardiográfica da função do ventrículo direito de cães da raça Boxer com cardiomiopatia arritmogênica do ventrículo direito : estudo caso-controle /

Fenerich, Michelli. January 2018 (has links)
Orientador: Aparecido Antonio Camacho / Resumo: A cardiomiopatia arritmogênica do ventrículo direito (CAVD) é uma doença de origem genética, muito prevalente em cães da raça Boxer. Histologicamente ocorre atrofia dos cardiomiócitos do ventrículo direito (VD) e consequente infiltração fibroadiposa, levando ao aparecimento de arritmias ventriculares. Mesmo sendo as alterações miocárdicas microscópicas em sua maioria, estudos recentes têm identificado disfunção contrátil do ventrículo direito, mesmo em estágios iniciais da doença em humanos, tanto por técnicas convencionais de ecocardiografia quanto por técnicas mais avançadas, como no caso do speckle tracking. Por isso, o objetivo deste estudo foi avaliar se há disfunção miocárdica de VD detectável pela ecocardiografia convencional e pela técnica de speckle tracking bidimensional em cães da raça Boxer portadores da CAVD. Para tanto, utilizou-se cães da raça Boxer com idade superior a quatro anos, distribuídos em dois grupos de acordo com o resultado da avaliação Holter (GC: < 50 EVs/24h, n=11 e GD: > 100 EVs/24h, n=11). Os animais foram submetidos a ecocardiografia e avaliou-se diâmetro e comprimento interno do VD em sístole e diástole, encurtamento fracional da área do VD (FAC), excursão sistólica do plano anular da tricúspide (TAPSE), velocidade miocárdica sistólica do ânulo lateral da tricúspide derivada do Doppler tecidual (S’) e deformação (strain) e taxa de deformação (strain rate) longitudinal global da parede livre do VD, derivados da análise por speckle tracking. As... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disease with a high prevalence in Boxer dogs. Histologically, right ventricle (RV) cardiomyocytes’ atrophy occurs, and thus fibrofatty infiltration, triggering ventricular arrhythmias. Although the myocardial changes are mostly microscopic, recent studies in human beings have identified right ventricular systolic dysfunction even in the early stages of ARVC, both by conventional echocardiographic techniques and advanced methods, such as speckle tracking. Therefore, the aim of this study was to investigate if RV myocardial dysfunction is present in Boxers affected by ARVC, evaluated by conventional echocardiography and bidimensional speckle tracking technique. For this purpose, Boxers older than four years were recruited, and based on 24-hour Holter recording were divided in groups: GC:< 50 VPC/24h (n=11), or GD: > 100 VPC/24h (n=11). The following echocardiographic parameters were analyzed: RV internal dimension during systole and diastole; RV fractional area change (FAC); tricuspid annular plane systolic excursion (TAPSE); myocardial systolic velocity of lateral tricuspid annulus (S’), and global longitudinal strain and strain rate. Groups were compared by Student’ t-test or Mann-Whitney test according distribution, and correlation between conventional and speckle tracking echocardiographic variables, as well as number and severity of the ventricular arrhythmias were accomplished by the Pearson test, assumin... (Complete abstract click electronic access below) / Mestre
4

In-vitro disease modelling of arrhythmogenic right ventricular cardiomyopathy using a transgene-free patient-specific induced pluripotent stem cell system

Ayetey, Harold January 2012 (has links)
No description available.
5

Pulmonary Vascular Mechanics in Long-standing Male Endurance Athletes at Rest and During Exercise

Gray, Taylor 26 November 2013 (has links)
This study examined right-ventricular-pulmonary arterial (RV-PA) coupling and pulmonary vascular mechanics during acute exercise in 12 middle-aged men with a long-standing history of endurance training. Subjects underwent simultaneous right-heart catheterization and echocardiography, with measures obtained at steady state heart rates of 100, 130 and 150 beats/min. Subjects were highly trained and displayed RV remodeling of endurance-trained athletes. During exercise at 100 beats/min, systolic, diastolic, and mean pulmonary artery pressure increased significantly from rest, as did pulmonary capillary wedge pressure. The slope of pooled mean pulmonary pressure indexed to cardiac output was 1.436 mmHg⋅min-1⋅L-1 with a distensibility index of 0.112 ± 0.048 mmHg-1. The pulmonary arterial elastance-RV end-systolic elastance ratio (Ea:Ees) decreased from rest to exercise at 130 beats/min (P < 0.01). These results suggest that Ea:Ees becomes favourable for RV function during exercise, indicative of a pulmonary vasculature that is highly distensible and well matched to RV output.
6

Pulmonary Vascular Mechanics in Long-standing Male Endurance Athletes at Rest and During Exercise

Gray, Taylor 26 November 2013 (has links)
This study examined right-ventricular-pulmonary arterial (RV-PA) coupling and pulmonary vascular mechanics during acute exercise in 12 middle-aged men with a long-standing history of endurance training. Subjects underwent simultaneous right-heart catheterization and echocardiography, with measures obtained at steady state heart rates of 100, 130 and 150 beats/min. Subjects were highly trained and displayed RV remodeling of endurance-trained athletes. During exercise at 100 beats/min, systolic, diastolic, and mean pulmonary artery pressure increased significantly from rest, as did pulmonary capillary wedge pressure. The slope of pooled mean pulmonary pressure indexed to cardiac output was 1.436 mmHg⋅min-1⋅L-1 with a distensibility index of 0.112 ± 0.048 mmHg-1. The pulmonary arterial elastance-RV end-systolic elastance ratio (Ea:Ees) decreased from rest to exercise at 130 beats/min (P < 0.01). These results suggest that Ea:Ees becomes favourable for RV function during exercise, indicative of a pulmonary vasculature that is highly distensible and well matched to RV output.
7

Avaliação ecocardiográfica da função do ventrículo direito de cães da raça Boxer com cardiomiopatia arritmogênica do ventrículo direito: estudo caso-controle / Echocardiographic assessment of right ventricular function in Boxer dogs with arrhythmogenic right ventricular cardiomyopathy: case-control study

Fenerich, Michelli 12 April 2018 (has links)
Submitted by Michelli Fenerich (michellifenerich@hotmail.com) on 2018-05-18T01:53:19Z No. of bitstreams: 1 Dissertação Michelli Fenerich FINAL.pdf: 780509 bytes, checksum: 243c644a7b86cf6eae0f835b726c9dea (MD5) / Rejected by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br), reason: Solicitamos que realize correções na submissão seguindo as orientações abaixo: O arquivo PDF submetido ao repositório deve conter o certificado de aprovação (documento obrigatório), favor inserir o mesmo no arquivo PDF e fazer novamente a submissão. Agradecemos a compreensão. on 2018-05-22T11:07:47Z (GMT) / Submitted by Michelli Fenerich (michellifenerich@hotmail.com) on 2018-05-23T00:06:49Z No. of bitstreams: 1 Dissertação Michelli Fenerich.pdf: 839583 bytes, checksum: 4eb04bc52d571c22b951ce3b11e0a705 (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-05-23T16:47:59Z (GMT) No. of bitstreams: 1 fenerich_m_me_jabo.pdf: 839583 bytes, checksum: 4eb04bc52d571c22b951ce3b11e0a705 (MD5) / Made available in DSpace on 2018-05-23T16:47:59Z (GMT). No. of bitstreams: 1 fenerich_m_me_jabo.pdf: 839583 bytes, checksum: 4eb04bc52d571c22b951ce3b11e0a705 (MD5) Previous issue date: 2018-04-12 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A cardiomiopatia arritmogênica do ventrículo direito (CAVD) é uma doença de origem genética, muito prevalente em cães da raça Boxer. Histologicamente ocorre atrofia dos cardiomiócitos do ventrículo direito (VD) e consequente infiltração fibroadiposa, levando ao aparecimento de arritmias ventriculares. Mesmo sendo as alterações miocárdicas microscópicas em sua maioria, estudos recentes têm identificado disfunção contrátil do ventrículo direito, mesmo em estágios iniciais da doença em humanos, tanto por técnicas convencionais de ecocardiografia quanto por técnicas mais avançadas, como no caso do speckle tracking. Por isso, o objetivo deste estudo foi avaliar se há disfunção miocárdica de VD detectável pela ecocardiografia convencional e pela técnica de speckle tracking bidimensional em cães da raça Boxer portadores da CAVD. Para tanto, utilizou-se cães da raça Boxer com idade superior a quatro anos, distribuídos em dois grupos de acordo com o resultado da avaliação Holter (GC: < 50 EVs/24h, n=11 e GD: > 100 EVs/24h, n=11). Os animais foram submetidos a ecocardiografia e avaliou-se diâmetro e comprimento interno do VD em sístole e diástole, encurtamento fracional da área do VD (FAC), excursão sistólica do plano anular da tricúspide (TAPSE), velocidade miocárdica sistólica do ânulo lateral da tricúspide derivada do Doppler tecidual (S’) e deformação (strain) e taxa de deformação (strain rate) longitudinal global da parede livre do VD, derivados da análise por speckle tracking. As variáveis foram comparadas entre os grupos pelo teste t de Student e de Mann-Whitney e a correlação entre variáveis ecocardiográficas convencionais e de speckle tracking e o número e severidade das arritmias pelo teste de correlação de Pearson, com nível de significância de 5%. Os grupos não foram estatisticamente diferentes e não houve correlação entre os dados. Os resultados da pesquisa demonstraram que a ecocardiografia, tanto na avaliação do VD por índices sistólicos convencionais quanto por aqueles derivados da técnica de speckle tracking não foram capazes de detectar disfunção miocárdica do VD em Boxers portadores de CAVD. / Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disease with a high prevalence in Boxer dogs. Histologically, right ventricle (RV) cardiomyocytes’ atrophy occurs, and thus fibrofatty infiltration, triggering ventricular arrhythmias. Although the myocardial changes are mostly microscopic, recent studies in human beings have identified right ventricular systolic dysfunction even in the early stages of ARVC, both by conventional echocardiographic techniques and advanced methods, such as speckle tracking. Therefore, the aim of this study was to investigate if RV myocardial dysfunction is present in Boxers affected by ARVC, evaluated by conventional echocardiography and bidimensional speckle tracking technique. For this purpose, Boxers older than four years were recruited, and based on 24-hour Holter recording were divided in groups: GC:< 50 VPC/24h (n=11), or GD: > 100 VPC/24h (n=11). The following echocardiographic parameters were analyzed: RV internal dimension during systole and diastole; RV fractional area change (FAC); tricuspid annular plane systolic excursion (TAPSE); myocardial systolic velocity of lateral tricuspid annulus (S’), and global longitudinal strain and strain rate. Groups were compared by Student’ t-test or Mann-Whitney test according distribution, and correlation between conventional and speckle tracking echocardiographic variables, as well as number and severity of the ventricular arrhythmias were accomplished by the Pearson test, assuming a level of significance at 5%. Groups were considered similar, and there was no correlation among the evaluated parameters. Our findings suggesting that the echocardiographic evaluation of RV, either by conventional and speckle tracking techniques, were not able to detect systolic myocardial dysfunction in Boxers affected by ARVC. / FAPESP: 16/14800-7
8

Biomechanical and Hemodynamic Measures of Right Ventricular Diastolic Function: Translating Tissue Biomechanics to Clinical Relevance

Jang, Sae, Vanderpool, Rebecca R., Avazmohammadi, Reza, Lapshin, Eugene, Bachman, Timothy N., Sacks, Michael, Simon, Marc A. 12 September 2017 (has links)
Background Right ventricular (RV) diastolic function has been associated with outcomes for patients with pulmonary hypertension; however, the relationship between biomechanics and hemodynamics in the right ventricle has not been studied. Methods and Results Rat models of RV pressure overload were obtained via pulmonary artery banding (PAB; control, n=7; PAB, n=5). At 3 weeks after banding, RV hemodynamics were measured using a conductance catheter. Biaxial mechanical properties of the RV free wall myocardium were obtained to extrapolate longitudinal and circumferential elastic modulus in low and high strain regions (E-1 and E-2, respectively). Hemodynamic analysis revealed significantly increased end-diastolic elastance (E-ed) in PAB (control: 55.1 mm Hg/mL [interquartile range: 44.785.4 mm Hg/mL]; PAB: 146.6 mm Hg/mL [interquartile range: 105.8155.0 mm Hg/mL]; P=0.010). Longitudinal E1 was increased in PAB (control: 7.2 kPa [interquartile range: 6.718.1 kPa]; PAB: 34.2 kPa [interquartile range: 18.144.6 kPa]; P=0.018), whereas there were no significant changes in longitudinal E-2 or circumferential E-1 and E-2. Last, wall stress was calculated from hemodynamic data by modeling the right ventricle as a sphere: (stress = Pressure x radius/2 x thickness Conclusions RV pressure overload in PAB rats resulted in an increase in diastolic myocardial stiffness reflected both hemodynamically, by an increase in E-ed, and biomechanically, by an increase in longitudinal E-1. Modest increases in tissue biomechanical stiffness are associated with large increases in E-ed. Hemodynamic measurements of RV diastolic function can be used to predict biomechanical changes in the myocardium.
9

Echocardiographic Assessment of Right Ventricular Systolic Function in Conscious Healthy Dogs

Visser, Lance Charles 28 August 2014 (has links)
No description available.
10

Pathophysiologie et pathobiologie de la défaillance ventriculaire droite

Dewachter, Céline January 2013 (has links)
Doctorat en Sciences médicales / info:eu-repo/semantics/nonPublished

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