• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 6
  • 3
  • 1
  • 1
  • 1
  • Tagged with
  • 14
  • 14
  • 8
  • 6
  • 6
  • 6
  • 5
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 2
  • 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

Adrenomedullin and natriuretic peptides in cardiac hypertrophy:regulation of gene expression and interactions with angiotensin II

Luodonpää, M. (Marja) 01 December 2004 (has links)
Abstract The heart responds to increased hemodynamic stress by increased cardiac myocyte size, enhanced protein synthesis and altered gene expression. Regulation of hypertrophic adaptation involves a number of neural and hormonal factors, which act on the cardiovascular system. The aim of the present study was to elucidate the regulation of gene expression of natriuretic peptides and adrenomedullin (AM) in cardiac overload in vivo. Furthermore, the interactions of AM and angiotensin II (Ang II) in cardiac function and development of left ventricular hypertrophy were studied both in vivo and in vitro. The effects of cardiac hypertrophy on the regulation of natriuretic peptides (atrial natriuretic peptide, ANP and B-type natriuretic peptide, BNP) and AM gene expression were studied during pressure overload in the hearts of two hypertensive rat strains, angiotensinogen-renin transgenic rats and spontaneously hypertensive rats as well as their normotensive control strains. Increased workload resulted in rapid upregulation of both BNP and AM gene expression in all rat strains; the response of AM was, however, augmented in hypertensive rats. Direct left ventricular wall stretch induced AM gene expression in isolated, perfused rat hearts, whereas stretching of cultured cardiac myocytes downregulated AM mRNA levels. In cultured cardiac cells exposed to Ang II, endothelin-1 or the α-agonist phenylephrine, Ang II-induced myocyte hypertrophy was selectively inhibited by AM. In vivo, AM interacted with Ang II in circulation by attenuating the hypertensive effects of Ang II, and in the heart by augmenting the Ang II-induced improvement in cardiac systolic function. However, AM had no direct modulatory effects on Ang II-induced left ventricular hypertrophy. These results show that cardiac wall stretch is a major stimulus for the early induction of AM gene expression in both normal and hypertrophied ventricle, and the response in hypertrophied myocardium is augmented. Furthermore, cardiac non-muscle cells may be involved in mediating effects of direct stretch. In vitro, AM acts as a selective inhibitor of Ang II-induced myocyte hypertrophy, suggesting a cardioprotective role for AM to counteract the local renin-angiotensin system and Ang II in cardiac hypertrophy and heart failure. Circulating AM appears to act mainly as a regulator of vascular tone and cardiac function.
2

LONG-TERM EFFECTS OF ESTROGEN DEFICIENCY ON CARDIAC SYSTOLIC FUNCTION AND HYPERTROPHY FOLLOWING CHRONIC SYMPATHETIC STIMULATION

Avendano, Pamela 01 May 2022 (has links)
Cardiovascular disease (CVD) is the leading cause of death worldwide. Pre-menopausal women have a lower incidence and severity of CVD compared to age-matched men. However, at the onset of menopause, CVD increases. A central feature in patients with CVD is excessive chronic sympathetic stimulation (CSS) of β-adrenergic receptors (β-AR’s). Clinical and animal studies show estrogen deficiency and age exacerbate cardiac β-AR signaling and contractile function. This led to the hypothesis that prolonged estrogen deficiency followed by CSS worsens left ventricular cardiac function and hypertrophy in the aged female heart. Female mice underwent bilateral ovariectomy or SHAM surgery at 2.5 months of age. At 12 months post-ovariectomy, mice were infused with Isoproterenol (400μg/kg/h) via mini-osmotic pumps for three days to induce CSS. This observation demonstrates prolonged estrogen deficiency worsens cardiac function and structure in aged female hearts. Thereby emphasizing the importance of clinical intervention and prevention for CVD in menopausal women.
3

Long-Term Effects of Estrogen Deficiency on Cardiac Systolic Function and Hypertrophy After Chronic Sympathetic Stimulation

Avendano, Pamela, McCustion, Pearl, Singh, Krishna, Foster, Cerrone R. 06 April 2022 (has links)
Cardiovascular disease (CVD) is the leading cause of death worldwide. The risks for women increase at the onset of menopause. A central feature in CVD patients is excessive sympathetic stimulation of beta-adrenergic receptors (β-ARs). Both clinical and animal studies show that estrogen loss and age exacerbate cardiac β-AR signaling and contractile function. We, therefore, examined the hypothesis that prolonged estrogen deficiency followed by chronic sympathetic injury worsens left ventricular cardiac function in the aged female heart. Bilateral ovariectomy (OVX) or SHAM surgery was performed in female mice at 2.5 months of age and infused with Isoproterenol (ISO; 400μg/kg/h) at 12 months (12M) post OVX for 3 days to induce chronic sympathetic stimulation. Transthoracic two-dimensional M-mode echocardiography was used to measure left ventricular (LV) wall thickness and left ventricular end-systolic diameter (LVESD) and left ventricular end-diastolic diameter (LVEDD), percent fractional shortening (%FS), and ejection fraction (EF). Animal body weight was measured to calculate the heart-body ratio, followed by the removal of the heart, left lung, and uterus during euthanasia. Tissue samples were treated with wheat germ agglutinin staining to measure cardiac myocyte cross-sectional area (hypertrophy). Results show that prolonged ovariectomy increased mortality in mice treated with ISO post-ovariectomy (OVX +ISO) compared to the SHAM+ISO group. Echocardiography imaging demonstrated a smaller systolic diameter and increased contractility in the ISO and ISO+OVX groups. OVX, ISO, and ISO+OVX treatment had a significant decrease in LVESD versus SHAM and OVX groups. The LVEDD resulted in a significant decrease with ISO treatment compared to the SHAM group, and no significant difference was observed between the OVX and ISO+OVX groups compared to the SHAM. Percent FS presented a significant increase in cardiac function in OVX, ISO, and ISO+OVX groups compared to the SHAM. There was an increased %FS in the ISO+OVX compared to the OVX group, and no significant difference between the ISO+OVX and ISO treatment groups. Percent EF significantly increased in the OVX, ISO, and ISO+OVX treatment groups from the SHAM and OVX group, and no significant difference between the ISO+OVX and ISO treatment groups. OVX increased left ventricular mass compared to SHAM. While ISO treatment did not increase LV mass ISO+OVX treatment group significantly increased in LV mass when compared to the ISO treatment group. There was no significant difference in the left ventricular mass between the ISO+OVX vs. OVX group. There was no significant difference in cardiac myocyte cross-sectional area in the SHAM, OVX vs ISO groups. There was however a significant increase in myocyte cross-sectional area in the ISO+OVX group compared to OVX treatment and ISO groups. The results presented here show that estrogen loss impairs left ventricular cardiac function and increases remodeling in response to β-AR stimulation and that prolonged estrogen loss may blunt the sympathetic response in the heart. These results highlight the importance of the long-term effects of estrogen loss during menopause in the treatment and management of heart disease.
4

Avaliação ecocardiográfica de coelhos submetidos à infusão contínua de lidocaína sedados com midazolam /

Marques, Ana Elisa Gregui Watanabe January 2019 (has links)
Orientador: Paulo Sergio Patto dos Santos / Resumo: A lidocaína é um fármaco versátil muito utilizado na rotina clínica. No entanto, há poucos estudos que avaliam os seus efeitos sobre o coração. Para esta finalidade, a ecocardiografia transtorácica é uma ferramenta que possibilitava a avaliação das funções sistólica e diastólica em tempo real. Como este estudo, objetivou-se avaliar os efeitos da infusão contínua de lidocaína sobre as funções sistólica e diastólica do ventrículo esquerdo de coelhos hígidos sedados com midazolam. Para tanto, foram utilizados dez coelhos da raça Nova Zelândia, quatro machos e seis fêmeas, com idade de nove meses, pesando 3,2 ± 0,3 kg, sendo todos os animais sedados com midazolam na dose de 1 mg/kg pela via intramuscular e submetidos a dois tratamentos experimentais (controle e lidocaína) com intervalo mínimo de sete dias entre os tratamentos. No tratamento controle (TC) administrou-se solução de cloreto de sódio a 0,9% (0,05 mL/kg) em bolus seguida de infusão contínua na taxa de 5 mL/hora; no tratamento lidocaína (TL) administrou-se primeiramente um bolus de lidocaína a 2% sem vasoconstritor na dose de 1 mg/kg seguido de infusão contínua na taxa de 50 µg/kg/minuto, sendo mantidos os mesmos volumes administrados para ambos os tratamentos. As principais variáveis analisadas foram: frequência cardíaca (FC), pressão arterial média (PAM), índice de resistência vascular periférica (IRVP), índice cardíaco Doppler (ICD), fração de encurtamento (FEC), fração de ejeção (FEJ), velocidade da onda S′ e relaç... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Lidocaine is a versatile drug widely used in clinical practice. However, there are few studies that evaluate its effects on the heart. For this purpose, transthoracic echocardiography is a tool that allows an evaluation of the systematic and diastolic units in real time. The aim of the study was evaluate the effects of continuous rate infusion of lidocaine on systolic and diastolic functions of the left ventricle of healthy rabbits sedated with midazolam. Ten New Zealand rabbits, four males and six females, aged nine months, weighing 3.2 ± 0.3 kg were sedated with midazolam at the dose of 1 mg/kg intramuscularly and submitted to two experimental treatments (control and lidocaine) with a minimum interval of seven days. In the control treatment (CT), 0.9% sodium chloride solution (0.05 mL.kg-1 ) was administered in bolus followed by continuous infusion at a rate of 5 mL.hour-1 ; a 2% lidocaine bolus without vasoconstrictor at the dose of 1 mg.kg-1 followed by continuous infusion at the rate of 50 μg.kg-1 .minute-1 was first given in lidocaine treatment (LT). The main variables analyzed were: heart rate (HR), mean arterial pressure (MAP), peripheral vascular resistance index (PVR), Doppler cardiac index (DCI), shortening fraction (FEC), ejection fraction (EFJ), velocity of the wave S 'and relation E'/A'. All parameters were evaluated before the onset of the bolus (MB) and 20, 40 and 60 minutes after the start of continuous rate infusion (M20, M40 and M60). The studied variables ... (Complete abstract click electronic access below) / Mestre
5

Ecocardiografia convencional e speckle tracking bidimensional em cães saudáveis anestesiados com sevofluorano e submetidos a infusão contínua de nalbufina /

Marques, Marcel Gambin January 2020 (has links)
Orientador: Paulo Sergio Patto dos Santos / Resumo: A nalbufina é um opioide agonista-antagonista com propriedades analgésicas adequadas e poucos efeitos depressores no sistema respiratório. Sua utilização na medicina veterinária é limitada pois muitos veterinários desconhecem suas vantagens. Além disso, seus efeitos na função cardíaca são pouco estudados. Portanto, com o estudo objetivou-se avaliar os efeitos da infusão contínua de nalbufina na função sistólica e diastólica do ventrículo esquerdo em cães saudáveis anestesiados com sevofluorano. Foram utilizados dezoito cães fêmeas de diversas raças ou sem raça definida, com idade média de 2 ± 1 anos e peso médio de 9,9 ± 3,8 kg. Os cães foram aleatoriamente submetidos a dois grupos denominados: nalbufina (GN) e controle (GC), com nove animais para cada grupo. Os animais foram induzidos e mantidos sob anestesia com sevofluorano (2V%). No GN foi administrado bolus intravenoso de nalbufina (0,3 mg/kg), seguido de infusão continua (0,4 mg/kg/h). O GC recebeu solução salina (NaCl 0,9%), em volumes idênticos em bolus e infusão ao GN. As variáveis ecocardiográficas de função sistólica e diastólica e os parâmetros hemodinâmicas foram determinadas no momento basal (antes do bolus) e 20, 40, 60 e 80 minutos após o início da infusão contínua. Não houve diferença entre os grupos para os parâmetros de função sistólica e diastólica ventricular esquerda derivados da ecocardiografia convencional e speckle tracking bidimensional. Do mesmo modo, as variáveis hemodinâmicas não apresentaram dife... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Nalbuphine is an agonist-antagonist opioid with adequate analgesic properties and few depressant effects on the respiratory system. Its use in veterinary medicine is limited due to the unknown of its effects on cardiac function. The aim of this study was to assess the effects of a continuous rate infusion (CRI) of nalbuphine on left ventricular systolic and diastolic function of healthy sevoflurane-anesthetized dogs. Were used eighteen mixed-breed bitches ageging 2 ± 1 years and weighing 9.9 ± 3.8 kg. Dogs were randomly assigned to one of two groups: nalbuphine (GN, n=9); and control (GC, n=9). Anesthesia was induced and maintained with sevoflurane (2V%) followed by an intravenous (IV) bolus of nalbuphine (0.3 mg/kg) or 0.9% NaCl at equal volume, then CRI of nalbuphine (0.4 mg/kg/h) or 0.9% NaCl at equal infusion rate. Echocardiographic and hemodynamic variables were determined at baseline and 20, 40, 60 and 80 minutes following start of CRI. No differences were found between groups for left ventricular systolic and diastolic variables obtained through conventional echocardiography and two-dimensional speckle tracking. Likewise, hemodynamic variables did not differ between groups. The E′/A′ ratio significantly increased at 20 minutes compared to baseline only in GN. Nalbuphine given at a CRI does not influence left ventricular systolic and diastolic function in healthy sevoflurane-anesthetized dogs. / Doutor
6

Avaliação ecocardiográfica dos índices de função sistólica e diastólica de cães com cardiomiopatia dilatada idiopática submetidos ao tratamento com carvedilol / Echocardiographic evaluation of systolic and diastolic parameters of dogs with dilated cardiomyopathy treated with carvedilol

Soares, Elaine Cristina 13 January 2006 (has links)
A cardiomiopatia dilatada idiopática (CMD) é a segunda cardiopatia mais prevalente na espécie canina, acometendo principalmente raças grandes e gigantes, bem como o Cocker Spaniel. É uma doença que possui alta letalidade, além de comprometer substancialmente a qualidade de vida do animal. O diagnóstico definitivo é realizado por meio da ecocardiografia, onde se observam dilatação das cavidades cardíacas, mais freqüentemente do ventrículo e átrio esquerdos, e diminuição da função sistólica. Estudos realizados em seres humanos com CMD mostram que, além da sistólica, a função diastólica está comprometida, e que a análise do fluxo transmitral, importante para a detecção de alterações de relaxamento e/ou distensibilidade tem importante valor prognóstico para a sobrevida e evolução dos sintomas. O tratamento da CMD tradicionalmente baseia-se na utilização de digitálicos, diuréticos, e vasodilatadores. Contudo, nos últimos anos, visto a importância da ativação do sistema nervoso simpático sobre a fisiopatologia desta doença, os β-bloqueadores têm sido empregados. Muitos trabalhos mostram que estes fármacos melhoram a função sistólica e/ou diastólica do ventrículo esquerdo, e com isso aumentam a sobrevida e diminuindo a progressão dos sintomas. Estudaram-se 45 cães com cardiomiopatia dilatada, que foram divididos em dois grupos (A e B). O grupo A (n=25) recebeu o tratamento convencional, ou seja, digitálicos, diuréticos e vasodilatadores, e o grupo B (n=20) recebeu estes mesmos medicamentos acrescidos do carvedilol, um β-bloqueador de terceira geração. Os animais foram submetidos aos exames clínico e ecocardiográfico antes e após três, 13, 26 e 52 semanas do início do tratamento ou até o óbito. Não foram observadas diferenças nos valores dos índices de função sistólica e diastólica entre os grupos. Verificou-se que o grupo tratado com carvedilol apresentou maior tempo médio de sobrevida, porém esta diferença não foi estatisticamente significante. Quanto aos sintomas (classe funcional), observou-se que o grupo tratado com carvedilol apresentou evolução mais favorável, com maior número de animais classificados como "sintomas leves" após três meses de tratamento. Assim, embora o carvedilol tenha se mostrado benéfico, principalmente com relação aos sintomas, não se pode correlacionar esta melhora à ação do fármaco sobre as funções sistólica e diastólica / Dilated Cardiomyopathy (DCM) is the second more common heart disease in dogs, wherein large and giant breeds, as well as Cockers Spaniels, are predisposed. Such disease has a high mortality rate besides reducing the quality of life of the affected animals. The definitive diagnosis is based upon echocardiography which is characterized by dilation of cardiac chambers, mainly the left ones, and by reduced systolic function. Human medicine studies have reported that the diastolic dysfunction also plays an important role; so, an abnormal transmitral flow pattern, which represents the ventricular diastolic filling, has a great prognostic value in terms of survival and symptoms status (heart failure functional class) The management of DCM traditionally consists of digitalis, diuretics and vasodilators, however, in the late years, some attention has being paid to the importance of the sympathetic nervous system on the pathophysiology of this disorder; being so, β-blockers have been included in the therapy. Many authors have reported that these drugs improve the left ventricle systolic and diastolic function, and so they increase the survival rate and reduce the symptoms progression. Forty-five dogs with idiopathic dilated cardiomyopathy, divided into two groups (A and B), were studied. The group A (n=25) consisted of dogs that were put on the traditional therapy (digitalis, diuretics and vasodilators) and the group B (n=20) included those who were treated with all these drugs plus carvedilol, a third generation β-blocker. The animals went through clinical and echocardiographic assesment before and 3, 13, 26 and 52 weeks after starting the treatment or until death. The variables of systolic and diastolic function were not statistically different between the two groups. The median survival time of the dogs treated with carvedilol was higher, but the difference was not statistically significant. Concerning to the symptoms (heart failure funcional class), dogs who were put on carvedilol had a better progression, as more of them were classified as "mild symptoms" after three months of therapy. In conclusion, despite the beneficial effects of carvedilol on the symptoms, these can not be correlate with the systolic and diastolic functions
7

Avaliação ecocardiográfica dos índices de função sistólica e diastólica de cães com cardiomiopatia dilatada idiopática submetidos ao tratamento com carvedilol / Echocardiographic evaluation of systolic and diastolic parameters of dogs with dilated cardiomyopathy treated with carvedilol

Elaine Cristina Soares 13 January 2006 (has links)
A cardiomiopatia dilatada idiopática (CMD) é a segunda cardiopatia mais prevalente na espécie canina, acometendo principalmente raças grandes e gigantes, bem como o Cocker Spaniel. É uma doença que possui alta letalidade, além de comprometer substancialmente a qualidade de vida do animal. O diagnóstico definitivo é realizado por meio da ecocardiografia, onde se observam dilatação das cavidades cardíacas, mais freqüentemente do ventrículo e átrio esquerdos, e diminuição da função sistólica. Estudos realizados em seres humanos com CMD mostram que, além da sistólica, a função diastólica está comprometida, e que a análise do fluxo transmitral, importante para a detecção de alterações de relaxamento e/ou distensibilidade tem importante valor prognóstico para a sobrevida e evolução dos sintomas. O tratamento da CMD tradicionalmente baseia-se na utilização de digitálicos, diuréticos, e vasodilatadores. Contudo, nos últimos anos, visto a importância da ativação do sistema nervoso simpático sobre a fisiopatologia desta doença, os β-bloqueadores têm sido empregados. Muitos trabalhos mostram que estes fármacos melhoram a função sistólica e/ou diastólica do ventrículo esquerdo, e com isso aumentam a sobrevida e diminuindo a progressão dos sintomas. Estudaram-se 45 cães com cardiomiopatia dilatada, que foram divididos em dois grupos (A e B). O grupo A (n=25) recebeu o tratamento convencional, ou seja, digitálicos, diuréticos e vasodilatadores, e o grupo B (n=20) recebeu estes mesmos medicamentos acrescidos do carvedilol, um β-bloqueador de terceira geração. Os animais foram submetidos aos exames clínico e ecocardiográfico antes e após três, 13, 26 e 52 semanas do início do tratamento ou até o óbito. Não foram observadas diferenças nos valores dos índices de função sistólica e diastólica entre os grupos. Verificou-se que o grupo tratado com carvedilol apresentou maior tempo médio de sobrevida, porém esta diferença não foi estatisticamente significante. Quanto aos sintomas (classe funcional), observou-se que o grupo tratado com carvedilol apresentou evolução mais favorável, com maior número de animais classificados como "sintomas leves" após três meses de tratamento. Assim, embora o carvedilol tenha se mostrado benéfico, principalmente com relação aos sintomas, não se pode correlacionar esta melhora à ação do fármaco sobre as funções sistólica e diastólica / Dilated Cardiomyopathy (DCM) is the second more common heart disease in dogs, wherein large and giant breeds, as well as Cockers Spaniels, are predisposed. Such disease has a high mortality rate besides reducing the quality of life of the affected animals. The definitive diagnosis is based upon echocardiography which is characterized by dilation of cardiac chambers, mainly the left ones, and by reduced systolic function. Human medicine studies have reported that the diastolic dysfunction also plays an important role; so, an abnormal transmitral flow pattern, which represents the ventricular diastolic filling, has a great prognostic value in terms of survival and symptoms status (heart failure functional class) The management of DCM traditionally consists of digitalis, diuretics and vasodilators, however, in the late years, some attention has being paid to the importance of the sympathetic nervous system on the pathophysiology of this disorder; being so, β-blockers have been included in the therapy. Many authors have reported that these drugs improve the left ventricle systolic and diastolic function, and so they increase the survival rate and reduce the symptoms progression. Forty-five dogs with idiopathic dilated cardiomyopathy, divided into two groups (A and B), were studied. The group A (n=25) consisted of dogs that were put on the traditional therapy (digitalis, diuretics and vasodilators) and the group B (n=20) included those who were treated with all these drugs plus carvedilol, a third generation β-blocker. The animals went through clinical and echocardiographic assesment before and 3, 13, 26 and 52 weeks after starting the treatment or until death. The variables of systolic and diastolic function were not statistically different between the two groups. The median survival time of the dogs treated with carvedilol was higher, but the difference was not statistically significant. Concerning to the symptoms (heart failure funcional class), dogs who were put on carvedilol had a better progression, as more of them were classified as "mild symptoms" after three months of therapy. In conclusion, despite the beneficial effects of carvedilol on the symptoms, these can not be correlate with the systolic and diastolic functions
8

Analyse échocardiographique des déformations myocardiques en speckle tracking / Myocardial deformations analysis by speckle tracking echocardiography

Réant, Patricia 15 December 2009 (has links)
L’analyse de la fonction systolique en échocardiographie représente un challenge majeur depuis une vingtaine d’années dans le but d’améliorer la détection et la quantification des anomalies de la contraction myocardique. L’analyse des déformations myocardiques consiste à étudier le pourcentage d’étirement ou de raccourcissement myocardiques au cours du cycle cardiaque. Après le grand pas en avant dans ce domaine, consécutif à l’avènement du Doppler tissulaire il y a un quinzaine d’années, ces 4 dernières années ont vu naître une nouvelle technique d’analyse bidimensionnelle des déformations, porteuse de grands espoirs car s’affranchissant de la limitation liée à l’angle d’incidence Doppler et basée sur le suivi des marqueurs acoustiques de la paroi myocardique : le « speckle tracking echocardiography » ou « 2D strain ». Cette thèse rapporte tout d’abord une série de travaux orientés sur la validation de ce nouvel outil. Nous avons ensuite appliqué expérimentalement cette technique pour évaluer sa capacité à détecter l’ischémie myocardique lors d’un examen de stress sous dobutamine en comparaison à l’analyse de perfusion myocardique en échographie de contraste. Enfin, nous exposons plusieurs expériences cliniques qui témoignent de quelques applications potentielles de cette technique dans la prise en charge des patients porteurs de cardiopathies diverses : myocardiopathie hypertrophique, fibrillation auriculaire paroxystique et recherche de viabilité sous faibles doses de dobutamine chez les patients porteurs d’une cardiopathie ischémique. / For 20 years, analysis of systolic myocardial function by echocardiography is a major challenge to improve the detection and the quantification of myocardial contractility abnormalities. The principle of myocardial deformation analysis consists in evaluating the percentage of myocardial thickening or shortening during the cardiac cycle. After a big step forward with the advent of tissue Doppler imaging for 15 years, the 4 last years have seen the apparition of a new technique of bidimensional analysis, without angle dependency, based on the tracking of the acoustic markers of the myocardial wall, and called « speckle tracking echocardiography » or « 2D strain ». This thesis reports serial studies oriented on the validation of this new tool and on the experimental application of this technique in the detection of myocardial ischemia during pharmacological dobutamine stress echocardiography, in comparison with myocardial perfusion analysis by contrast echocardiography. Finally, we report some clinical experiences using the speckle tracking echocardiography which attest of some clinical potential applications of this technique in the management of the patients with different cardiomyopathies: hypertrophic cardiomyopathy, lone paroxysmal atrial fibrillation, and analysis of myocardial regional deformation during low doses dobutamine infusion to investigate viability in patients with ischemic cardiomyopathy.
9

Sambandet mellan TAPSE och RVs´ vid bedömning av RV:s funktion med ekokardiografi hos hjärtfriska individer : En jämförande studie / The relationship between TAPSE and RVs' when assessing RV function with echocardiography in heart healthy individuals : A comparative study

Wafaa, Hamsho, Hosseinzadeh, Sousan January 2023 (has links)
Högerkammare (RV) har en komplex anatomi, spelar en viktig roll för blodsyresättning och kan påverkas av fler patofysiologiska tillstånd. Utvärdering av RV:s funktion är viktig för överlevnad och har prognostiskt värde vid hjärt-och lungsjukdomar. Transthorakal ekokardiografi (TTE) används för RV:s storlek- och funktionsbedömning. Tricuspid annular plane systolic excursion (TAPSE) och annulus tricuspid peak systolic velocity (RVs´) är två vanliga metoder för bedömning av RV:s funktion. Båda metoderna har bra reproducerbarhet och är enkla att utföra.  Syftet med detta arbete är att utreda interobservatörvariation, sambandet och överensstämmelse mellan TAPSE och RVs´. Studien är en tvärsnittsstudie av 53 friska testpersoner 18-60 åringar. Mätningen baserades på en blind dubbelbestämning av två biomedicinska analytiker studenter. Analysen genomfördes med programmet IBM SPSS Statistics.  Interobservatörvariationsanalys visade ingen signifikant skillnad i mätosäkerheten mellan studenterna, (PTAPSE=0,568 och PRVs´=0,548). Enligt regressionsanalysen hade RVs´ något mindre mätosäkerhet än TAPSE. Ett svagt positivt samband hittades mellan RVs´ och TAPSE och 100% överenstämmelse avseende utfall påvisades, Kappavärdet blev 1. Båda metoderna har bra interobservatörvariation hos oerfarna undersökare. Hos hjärt- och lungfriska ser sambandet svagt positivt ut mellan TAPSE och RVs´. Dock kunde tidigare studier identifiera starkare positivt samband. Skillnaden i resultatet kan bero på erfarenhetsbrist hos studenterna och lågt antal deltagare. / The Right ventricle (RV) has a complex anatomy, plays an important role in blood oxygenation and can be affected by several pathophysiological conditions. Evaluation of RV function has prognostic value in heart and lung diseases. Tricuspid annular plane systolic excursion (TAPSE) and annulus tricuspid peak systolic velocity (RVs´) are two common methods for assessing RV function in Transthoracic echocardiography.  The study aimed to investigate interobserver variation, the correlation and agreement between TAPSE and RVs´. The study is a cross-sectional study of 53 healthy participants aged 18-60. The measurement was based on a blind double determination by two biomedical analyst students. The analysis was implemented with the program IBM SPSS Statistics. Interobserver variation analysis showed no significant difference between the two students, (PTAPSE =0,568 and PRVs´=0,548). Regression analysis showed RVs´ had slightly less measurement uncertainty than TAPSE. A weak positive correlation was found between RVs´ and TAPSE and 100% agreement regarding outcome was demonstrated, Kappa value was 1. Both methods have good interobserver variation in inexperienced examiners. In people with healthy heart and lungs, the relationship between TAPSE and RVs looks weakly positive. Previous studies identified stronger positive association. Differences in the results may be due to a lack of experience on the part of the students and a low number of participants.
10

Função atrial na miocardiopatia chagásica crônica / Evaluation of atrial function in patients with chronic chagasic cardiomyopathy

Fragata, Claudia da Silva 01 March 2013 (has links)
INTRODUÇÃO: A doença de Chagas tem patogênese não totalmente conhecida. Ao contrário das funções sistólica e diastólica do ventrículo esquerdo, a função do átrio esquerdo carece de informações. OBJETIVOS: Em portadores de doença de Chagas, com ou sem alterações eletrocardiográficas, com ou sem disfunção sistólica de ventrículo esquerdo, verificar se há diferença nos parâmetros de função atrial esquerda e se há correlação entre dados de função de átrio esquerdo e parâmetros ecodopplercardiográficos de função ventricular sistólica e diastólica de ventrículo esquerdo MÉTODOS: 85 indivíduos: 10 controles (GC), 26 na forma indeterminada (GI), 30 com alterações eletrocardiográficas somente (GII) e 19 com disfunção ventricular (GIII), submetidos a ecocardiograma para avaliação da função atrial e das funções sistólicas e diastólicas ventriculares. Para analise estatística foi utilizado teste de Kruskal-Wallis e o coeficiente de Spearman. RESULTADOS: Função de reservatório (FET: fração de esvaziamento total): Houve diferença entre os grupos (p < 0,0001), média menor no GIII comparado ao GC (p = 0,003), ao GI (p < 0,001) e GII (p < 0,001), sem diferença entre GC, GI e GII. Fluxo de veias pulmonares: na onda S houve diferença entre os grupos (p = 0,003), média menor no GIII comparada ao GC (p = 0,01). Função de conduto (FEP: fração de esvaziamento passivo): houve diferença entre os grupos (p = 0,004), média menor no GIII, sem significância estatística comparando entre os grupos (GIII e GC, p = 0,06, GI e GII, p = 0,06, e GII e GIII, p = 0,07). Função de bomba propulsora (FEA: fração de esvaziamento ativo): houve diferença entre os grupos (p = 0,0001), média menor no GIII comparado ao GC (p = 0,05), ao GI (p < 0,0001) e ao GII (p = 0,002). Correlações: E/e\'média e FET: fraca correlação negativa (r = - 0,263; p = 0,02), moderada correlação negativa no GIII (r = - 0,58; p = 0,02). E/e\'média e FEP: não houve correlação (r = - 0,09; p = 0,44). E/e\'média e FEA: moderada correlação negativa (r = -0,36; p = 0,002) e no GIII (r = - 0,57; p = 0,04). e\'média e FET: moderada correlação positiva (r = 0,53; p < 0,0001). e\'média e FEP: moderada correlação positiva (r = 0,49; p < 0,0001). e\'média e FEA: moderada correlação positiva (r = 0,39; p = 0,001). Fração de ejeção do VE e FET: moderada correlação positiva (r = 0,35; p = 0,003) e no GIII (r = 0,52; p = 0,04). Fração de ejeção do VE e FEP: moderada correlação positiva (r = 0,42; p < 0,0001). Fração de ejeção do VE e FEA: moderada correlação positiva (r = 0,35; p = 0,003). CONCLUSÕES: Em pacientes com miocardiopatia chagásica com disfunção sistólica de ventrículo esquerdo, houve comprometimento das funções de reservatório, de conduto e bomba propulsora do átrio esquerdo e aqueles com função sistólica normal não apresentaram alterações nessas funções / BACKGROUND: Chagas disease (CD) pathogenesis is not fully known. Unlike the systolic and diastolic function of the left ventricle, the left atrial function still lacks information. OBJECTIVES: The aim of this study was to observe differences in patients with CD regarding the parameters of left atrial function and correlate them with Doppler echocardiographic parameters CASUISTIC AND METHODS: 85 subjects: 10 controls (GC), 26 in the indeterminate form (GI), 30 with ECG changes and normal left systolic function (GII) and 19 with left ventricular dysfunction (GIII) underwent echocardiography to assess left atrial and ventricular systolic and diastolic functions RESULTS: Reservoir function (TEF: total emptying fraction): there was a difference between groups (p <0.0001), lower mean in GIII compared to CG (p = 0.003), GI (p <0.001) and GII (p <0.001) with no difference between GC, GI and GII. Pulmonary veins flow: the S wave was no difference between groups (p = 0.003), lower mean in GIII compared to the CG (p = 0.01). Conduit function (PEF: passive emptying fraction): there was a difference between groups (p = 0.004), lower mean in GIII, without statistical significance between groups (GIII and GC, p = 0.06, GI and GII, p = 0.06, and GII and GIII, p = 0.07). Pump function (AEF: active emptying fraction): there was a difference between groups (p = 0.0001), lower mean in GIII compared to CG (p = 0.05), GI (p <0.0001) and GII (p = 0.002). Correlations: E/e\'mean and TEF: weak negative correlation (r = - 0.263, p = 0.02), moderate negative correlation in GIII (r = - 0.58, p = 0.02). E/e\'mean and PEF: no correlation (r = - 0.09, p = 0.44). E/e\'mean and AEF: moderate negative correlation (r = -0.36, p = 0.002) and GIII (r = - 0.57, p = 0.04). e\'mean and TEF: moderate positive correlation (r = 0.53, p <0.0001). e\'mean and PEF: moderate positive correlation (r = 0.49, p <0.0001). e\'mean and AEF: moderate positive correlation (r = 0.39, p = 0.001). LV ejection fraction and TEF: moderate positive correlation (r = 0.35, p = 0.003) and GIII (r = 0.52, p = 0.04). LV ejection fraction and PEF: moderate positive correlation (r = 0.42, p <0.0001). LV ejection fraction and AEF: moderate positive correlation (r = 0.35, p = 0.003). CONCLUSIONS: In patients with Chagas\' cardiomyopathy with left ventricular systolic dysfunction, there was impairment of the functions of reservoirs, conduit and pump of the left atrium

Page generated in 0.0761 seconds