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1.
BMC Cancer ; 20(1): 550, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32539683

RESUMO

BACKGROUND: Regarding the longer-term recurrence rate the optimal activity for the remnant thyroid ablation in patients with differentiated thyroid cancer (DTC) is discussed controversially. For the short-term ablation success rate up to 12 months there are already several meta-analyses. In this study we performed the first meta-analysis regarding the longer-term recurrence rate after radioactive 131-I administration. METHODS: We conducted an electronic search using PubMed/MEDLINE, EMBASE and the Cochrane Library. All randomized controlled trials (RCTs) assessed the recurrence rate after radioactive iodine ablation in patients with DTC, with a follow-up of at least two years were selected. Statistics were performed by using Review Manager version 5.3 and Stata software. RESULTS: Four RCTs were included in the study, involving 1501 patients. There was no indication for heterogeneity (I2 = 0%) and publication bias. The recurrence rate among patients who had a low dose 131-iodine ablation was not higher than for a high dose activity (odds ratio (OR) 0.93 [95% confidence interval (CI) 0.53-1.63]; P = 0.79). The mean follow-up time was between 4.25 and 10 years. The subgroup analysis regarding the TSH stimulated thyroglobulin values (< 10 ng/mL versus < 2 ng/mL versus ≤1 ng/mL) showed no influence on recurrence rate. CONCLUSIONS: For the first time we showed that the longer-term, at least 2-year follow-up, recurrence rate among patients who had 131-iodine ablation with 1.1 GBq was not higher than with 3.7 GBq.


Assuntos
Radioisótopos do Iodo/administração & dosagem , Recidiva Local de Neoplasia/epidemiologia , Compostos Radiofarmacêuticos/administração & dosagem , Neoplasias da Glândula Tireoide/terapia , Relação Dose-Resposta à Radiação , Seguimentos , Humanos , Recidiva Local de Neoplasia/prevenção & controle , Radioterapia Adjuvante/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Glândula Tireoide/patologia , Glândula Tireoide/efeitos da radiação , Glândula Tireoide/cirurgia , Neoplasias da Glândula Tireoide/patologia , Tireoidectomia , Fatores de Tempo , Resultado do Tratamento
2.
BMC Cardiovasc Disord ; 16(1): 205, 2016 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-27793097

RESUMO

BACKGROUND: Fabry disease is characterized by a progressive deposition of sphingolipids in different organ systems, whereby cardiac involvement leads to death. We hypothesize that lysosomal storage of sphingolipids in the heart as occurring in Fabry disease does not reflect in higher cardiac lipid concentrations detectable by 1H magnetic resonance spectroscopy (MRS) at 3 Tesla. METHODS: Myocardial lipid content was quantified in vivo by 1H-MRS in 30 patients (12 male, 18 female; 18 patients treated with enzyme replacement therapy) with genetically proven Fabry disease and in 30 healthy controls. The study protocol combined 1H-MRS with cardiac cine imaging and LGE MRI in a single examination. RESULTS: Myocardial lipid content was not significantly elevated in Fabry disease (p = 0.225). Left ventricular (LV) mass was significantly higher in patients suffering from Fabry disease compared to controls (p = 0.019). Comparison of patients without signs of myocardial fibrosis in MRI (LGE negative; n = 12) to patients with signs of fibrosis (LGE positive; n = 18) revealed similar myocardial lipid content in both groups (p > 0.05), while the latter showed a trend towards elevated LV mass (p = 0.076). CONCLUSIONS: This study demonstrates the potential of lipid metabolic investigation embedded in a comprehensive examination of cardiac morphology and function in Fabry disease. There was no evidence that lysosomal storage of sphingolipids influences cardiac lipid content as measured by 1H-MRS. Finally, the authors share the opinion that a comprehensive cardiac examination including three subsections (LGE; 1H-MRS; T1 mapping), could hold the highest potential for the final assessment of early and late myocardial changes in Fabry disease.


Assuntos
Cardiomiopatias/metabolismo , Doença de Fabry/diagnóstico , Imagem Cinética por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Miocárdio/metabolismo , Esfingolipídeos/metabolismo , Adolescente , Adulto , Idoso , Cardiomiopatias/diagnóstico , Cardiomiopatias/etiologia , Doença de Fabry/complicações , Doença de Fabry/metabolismo , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Fatores de Tempo , Função Ventricular Esquerda , Adulto Jovem
3.
Herz ; 40(2): 240-9, 2015 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-23942734

RESUMO

The visual echocardiographic evaluation of left ventricular (LV) systolic function can be cumbersome, especially in patients with poor image quality. This review describes several alternative echocardiographic methods to determine LV systolic function: endocardial border delineation by contrast agents, mitral annular plane systolic excursion, mitral annular velocity derived from tissue Doppler, myocardial performance index, mitral regurgitation derived LV dP/dtMax and estimation of cardiac output by Doppler echocardiography. The review introduces the respective methods along with the presentation of suitable measurements, clinical implications and methodological limitations.


Assuntos
Algoritmos , Ecocardiografia Doppler/métodos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Volume Sistólico , Disfunção Ventricular Esquerda/diagnóstico por imagem , Meios de Contraste , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
4.
Herz ; 40 Suppl 1: 85-90, 2015 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-24848865

RESUMO

Friedreich's ataxia is a rare hereditary disease and although the gene defect has already been identified as a deficiency of the mitochondrial protein frataxin, the pathophysiology is still unknown. Although a multisystem disorder organ involvement is predominantly neurological. Besides the characteristic features of spinocerebellar ataxia the heart is frequently also affected. Cardiac involvement typically manifests as hypertrophic cardiomyopathy, which can progress to heart failure and death. So far most research has focused on the neurological aspects and cardiac involvement in Friedreich's ataxia has not been systematically investigated. Thus, a better understanding of the progression of the cardiomyopathy, cardiac complications and long-term cardiac outcome is warranted. Although no specific treatment is available general cardiac therapeutic options for cardiomyopathy should be considered. The current review focuses on clinical and diagnostic features of cardiomyopathy and discusses potential therapeutic developments for Friedreich's ataxia.


Assuntos
Cardiomiopatia Hipertrófica/etiologia , Cardiomiopatia Hipertrófica/fisiopatologia , Ataxia de Friedreich/complicações , Ataxia de Friedreich/fisiopatologia , Humanos , Modelos Cardiovasculares , Fatores de Risco
5.
J Intern Med ; 274(4): 331-41, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23586858

RESUMO

OBJECTIVE: The long-term effects of enzyme-replacement therapy (ERT) in Fabry disease are unknown. Thus, the aim of this study was to determine whether ERT in patients with advanced Fabry disease affects progression towards 'hard' clinical end-points in comparison with the natural course of the disease. METHODS: A total of 40 patients with genetically proven Fabry disease (mean age 40 ± 9 years; n = 9 women) were treated prospectively with ERT for 6 years. In addition, 40 subjects from the Fabry Registry, matched for age, sex, chronic kidney disease stage and previous transient ischaemic attack (TIA), served as a comparison group. The main outcome was a composite of stroke, end-stage renal disease (ESRD) and death. Secondary outcomes included changes in myocardial left ventricular (LV) wall thickness and replacement fibrosis, change in glomerular filtration rate (GFR), new TIA and change in neuropathic pain. RESULTS: During a median follow-up of 6.0 years (bottom and top quartiles: 5.1, 7.2), 15 events occurred in 13 patients (n = 7 deaths, n = 4 cases of ESRD and n = 4 strokes). Sudden death occurred (n = 6) only in patients with documented ventricular tachycardia and myocardial replacement fibrosis. The annual progression of myocardial LV fibrosis in the entire cohort was 0.6 ± 0.7%. As a result, posterior end-diastolic wall thinning was observed (baseline, 13.2 ± 2.0 mm; follow-up, 11.4 ± 2.1 mm; P < 0.01). GFR decreased by 2.3 ± 4.6 mL min(-1) per year. Three patients experienced a TIA. The major clinical symptom was neuropathic pain (n = 37), and this symptom improved in 25 patients. The event rate was not different between the ERT group and the untreated (natural history) group of the Fabry Registry. CONCLUSION: Despite ERT, clinically meaningful events including sudden cardiac death continue to develop in patients with advanced Fabry disease.


Assuntos
Morte Súbita Cardíaca , Terapia de Reposição de Enzimas , Doença de Fabry/tratamento farmacológico , Isoenzimas/uso terapêutico , Falência Renal Crônica/diagnóstico , Acidente Vascular Cerebral/diagnóstico , alfa-Galactosidase/uso terapêutico , Adulto , Estudos de Coortes , Progressão da Doença , Doença de Fabry/diagnóstico , Feminino , Taxa de Filtração Glomerular , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Tempo , Resultado do Tratamento
6.
Herz ; 38(1): 42-7, 2013 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-23188160

RESUMO

The term diabetic cardiomyopathy was initially introduced in the 1980s when evidence was found that diabetes leads to a distinct cardiomyopathy, independent of coronary artery disease or hypertension. The detection of diabetic cardiomyopathy using echocardiography is challenging because no pathognomonic signs exist; however, it is the merit especially of the newer echocardiographic techniques, such as deformation imaging, that it is now possible to describe the morphology and function of diabetic hearts. Unfortunately, no long-term echocardiography studies are available describing disease progression in detail. Therefore, staging and differential diagnosis of diabetic cardiomyopathy remains challenging. This review tries to fill this gap by presenting a possible echocardiographic staging algorithm. Early stages of diabetic cardiomyopathy are marked by a deterioration of longitudinal systolic function and a compensative elevated radial function. Diastolic dysfunction is another early sign. When the disease progresses the functional deterioration is accompanied by morphological changes, such as left ventricular concentric hypertrophy and fibrosis. End stage disease is characterized by reduced ejection fraction and ventricular dilatation. Very late stage can mimic dilative cardiomyopathy.


Assuntos
Cardiomiopatias Diabéticas/diagnóstico por imagem , Ecocardiografia/métodos , Volume Sistólico , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/etiologia , Cardiomiopatias Diabéticas/complicações , Humanos
7.
Herz ; 38(1): 18-25, 2013 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-23324920

RESUMO

Diastolic heart failure, also known as heart failure with preserved left ventricular ejection fraction (HF-pEF), is responsible for approximately 50 % of all heart failure cases. According to current guidelines the diagnosis HF-pEF requires three criteria: (1) signs or symptoms of heart failure, (2) presence of a normal left ventricular ejection fraction and (3) evidence of diastolic dysfunction. Echocardiography is the diagnostic modality of choice, especially after ruling out other causes of dyspnea, such as pulmonary diseases, heart rhythm disturbances and volume overload. Important echocardiographic parameters for the assessment of diastolic function are atrial dimensions, myocardial mass, mitral inflow pattern, pulmonary vein flow, propagation velocity of mitral inflow and the tissue Doppler of the mitral annulus. Nevertheless, a complete echocardiographic examination should be performed in every patient with heart failure. In general, diastolic dysfunction is frequently associated with increased atrial diameter and left ventricular hypertrophy. In advanced stages pulmonary hypertension can be present. A robust method for evaluation of systolic function in patients with diastolic dysfunction is crucial. The mitral inflow pattern provides various parameters to describe diastolic function (E/A ratio, deceleration time, isovolumetric relaxation time). In case of difficulties to separate a normal from a pseudonormal mitral inflow pattern the Valsalva maneuver can be used. Another valuable parameter for this differentiation is the duration of the backward flow in the pulmonary veins in contrast to forward flow over the mitral valve. Tachycardia or atrial fibrillation is a major problem for grading of diastolic function; however, in patients with atrial fibrillation E/e' is a well-established parameter. In summary, this review provides a detailed overview and discussion of the established and newer echocardiography techniques for the evaluation of diastolic function and provides an algorithm for the assessment of diastolic dysfunction in everyday routine.


Assuntos
Ecocardiografia/métodos , Insuficiência Cardíaca Diastólica/complicações , Insuficiência Cardíaca Diastólica/diagnóstico por imagem , Aumento da Imagem/métodos , Volume Sistólico , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/etiologia , Ecocardiografia/tendências , Humanos
8.
Herz ; 38(3): 261-8, 2013 May.
Artigo em Alemão | MEDLINE | ID: mdl-22736038

RESUMO

Low gradient aortic stenoses (AS) represent a special challenge for physicians with respect to an exact diagnosis and optimal therapy. The difficulty lies in the estimation of the severity of AS which is decisive for subsequent treatment and the prognosis. Low flow and low gradient can be due to systolic or diastolic dysfunction by high-grade as well as by medium-grade AS and be of non-valvular origin. The latter group is to be interpreted as pseudoaortic stenosis as long as the low flow can successfully be raised by interventional means. However, only patients in the first group can be expected to profit from valve replacement and for patients in the second group the accompanying diseases must be the focus of therapeutic treatment. Therefore, according to recent European surveys up to 30% of patients with severe AS are undertreated due to false estimation of the severity of stenosis and perioperative risk stratification. Furthermore, follow-up investigations have shown that patients with low flow/low gradient stenosis and borderline-normal ejection fraction (EF) are in an advanced stage of the disease because they have often developed a severe reduction in longitudinal myocardial function and in addition have pronounced myocardial replacement fibrosis due to cardiac remodelling despite a preserved EF. Therefore, aortic valve area, mean pressure gradient and EF alone cannot be taken into consideration for the management of patients with severe AS but a comprehensive assessment of the hemodynamics, such as stroke volume, special functional parameters as well as individual clinical appearance is essential for precise diagnostic and therapeutic decision making.


Assuntos
Estenose da Valva Aórtica/diagnóstico , Estenose da Valva Aórtica/cirurgia , Tomada de Decisões , Índice de Gravidade de Doença , Disfunção Ventricular Esquerda/diagnóstico , Disfunção Ventricular Esquerda/cirurgia , Estenose da Valva Aórtica/complicações , Diagnóstico Diferencial , Humanos , Disfunção Ventricular Esquerda/etiologia
9.
Internist (Berl) ; 54(1): 121-2, 124-30, 2013 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-23250563

RESUMO

Fabry's disease is an X-chromosome linked lysosomal storage disorder with α-galactosidase A deficiency and subsequent multiple organ involvement. An early and common symptom also in later stages of the disease is pain. This pain depends on various precipitating factors and can severely compromise the quality of life. So-called Fabry crises can lead to the necessity for intensive care treatment. The pain can be classified as predominantly neuropathic and is difficult to treat. In addition, medication has to be adjusted to concomitant cardiac and renal involvement in Fabry's disease. This review gives guidance for pain therapy in Fabry's disease based on the available evidence and on experience.


Assuntos
Analgésicos/uso terapêutico , Doença de Fabry/complicações , Doença de Fabry/terapia , Neuralgia/etiologia , Neuralgia/terapia , Doença de Fabry/diagnóstico , Humanos , Neuralgia/diagnóstico
10.
Herz ; 36(8): 713-23, 2011 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-21246178

RESUMO

Left ventricular hypertrophy is a non-specific physiological or maladaptive cardiac response to a large array of stimuli mediated by exercise and numerous cardiac and systemic diseases. The precise characterization and quantification of left ventricular hypertrophy may allow a more timely diagnosis of the underlying condition. The clinical reference standard to assess left ventricular hypertrophy is echocardiography, but a comprehensive description of how to approach this frequent finding in clinical practice is lacking. The current review systematically describes the typical echocardiographic patterns of important types of cardiac hypertrophy using both established and advanced imaging modalities. In hypertrophic obstructive cardiomyopathy a markedly reduced regional systolic function is found in the prominent thickened septum, whereas in essential arterial hypertension a typical concentric left ventricular hypertrophy with a less prominent basal septal bulge is present. The echocardiographic characteristics of cardiac amyloidosis are ventricular hypertrophy with sparkling granular myocardial texture and a small epicardial effusion. In addition, the strain rate curve for longitudinal function shows a typically reduced function which reaches maximum already in early systole. The typical feature of Friedreich cardiomyopathy is concentric left ventricular hypertrophy and sparkling granular texture with preserved regional systolic function. In Fabry cardiomyopathy a prominent papillary muscle is presented and a typical strain rate curve can be extracted from the basal lateral wall, indicating replacement fibrosis. Prominent hypertrabecularisation (ratio of non-compacted to compacted myocardium >2) in the apical and mid left ventricular segments is typical for non-compaction cardiomyopathy. Knowledge of these typical echocardiographic features enables the cardiologist to distinguish between the different hypertrophic entities, thus paving the way to early diagnosis.


Assuntos
Ecocardiografia/métodos , Técnicas de Imagem por Elasticidade/métodos , Hipertrofia Ventricular Esquerda/classificação , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Humanos
11.
Hand Surg Rehabil ; 40(4): 472-476, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33744483

RESUMO

Traditionally, the angle between the intersecting central axes (lateral projection intersecting central axes - LCA) of the proximal and distal fragments of metacarpal fractures is measured on radiographs. We recommend using the angle between the intersecting dorsal tangent lines instead (lateral projection intersecting dorsal tangent lines - LDT). We analyzed radiographs of 25 fractures of the fifth metacarpal bone shaft in three planes. Intraclass correlation coefficients (ICC) were used to estimate inter-rater and intra-rater reliability. Mean palmar tilt was 35.6° ± 12.5° according to LCA and 27.6° ± 12.0° according to LDT. There were no differences during repeated measurements. Intra-rater reliability was high: ICC (95% CI) for LDT was 0.82 (0.74-0.88) and for LCA it was 0.71 (0.51-0.83). Mean values of palmar tilt using LCA exceeded those using LDT by 8.0° ± 7.7° (p < 0.001). Only LDT measurements provided comparable results between all raters. In conclusion, we demonstrated the feasibility and reliability of intersecting dorsal tangent lines for measuring palmar tilt in fifth metacarpal fractures as an alternative to the commonly used angle between the intersecting central axes.


Assuntos
Fraturas Ósseas , Traumatismos da Mão , Ossos Metacarpais , Fraturas Ósseas/diagnóstico por imagem , Humanos , Ossos Metacarpais/diagnóstico por imagem , Ossos Metacarpais/lesões , Radiografia , Reprodutibilidade dos Testes
12.
Radiologe ; 50(6): 541-7, 2010 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-20521022

RESUMO

Aortic valve disease shows a rising incidence with the increasing mean age of Western populations. The detection of hemodynamic parameters, which transcends the mere assessment of valve morphology, has an important future potential concerning classification of the severity of disease. MRI allows a non-invasive and a spatially flexible view of the aortic valve and the adjacent anatomic region, left ventricular outflow tract (LVOT) and ascending aorta. Moreover, the technique allows the determination of functional hemodynamic parameters, such as flow velocities and effective orifice areas. The new approach of a serial systolic planimetry velocity-encoded MRI sequence (VENC-MRI) facilitates the sizing of blood-filled cardiac structures with the registration of changes in magnitude during systole. Additionally, the subvalvular VENC-MRI measurements improve the clinically important exact determination of the LVOT area with respect to its specific eccentric configuration and its systolic deformity.


Assuntos
Algoritmos , Insuficiência da Valva Aórtica/diagnóstico , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
14.
Internist (Berl) ; 50(2): 225-9, 2009 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-19183921

RESUMO

Cardiac amyloidosis represents a prognostically relevant comorbidity in multiple myeloma. We report the case of a patient in whom severe heart failure symptoms as a consequence of cardiac AL-amyloidosis resolved after tandem high-dose melphalan therapy followed by autologous blood-stem cell transplantation. Partial regression of cardiac amyloid deposits and improvement of cardiac function were objectified.


Assuntos
Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/etiologia , Mieloma Múltiplo/complicações , Mieloma Múltiplo/diagnóstico , Insuficiência Cardíaca/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/terapia
15.
Eur J Clin Invest ; 38(3): 191-6, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18257782

RESUMO

BACKGROUND: Signs and symptoms of classic Fabry disease manifest itself on the skin (angiokeratoma), the nervous system (acroparaesthesia), the heart (restrictive cardiomyopathy) and a variety of other organs. MATERIALS AND METHODS: Diagnosis of Fabry disease was confirmed by genetic tests in a cohort of 100 patients and a standardized examination programme was performed in all patients. We were puzzled when applying well-established and textbook-anchored signs and symptoms to our patients. RESULTS: Among the 47 male and 53 female patients (mean age 41 +/- 16 years) with genetically proven disease, the Fabry-type vascular skin lesions were without hyperkeratotic aspect and keratomas were virtually absent. The peripheral neuropathic pain found in all male patients was not compatible with the wording 'acro' and 'paraesthesia', suggesting a different pathophysiological mechanism. Upon echocardiographic examination, patients mainly revealed diastolic relaxation abnormalities of the heart and only one patient had a restrictive cardiac pattern. CONCLUSIONS: Our findings suggest that some terms used to describe signs and symptoms of Fabry disease are historically derived and do not comply with state-of-the-art examination. We propose to replace the term 'angiokeratoma' with 'angioma', the term 'acroparaesthesia' with 'neuropathic pain' and the term 'restrictive cardiomyopathy' with 'cardiac hypertrophic storage disease'. As most of the physicians are not familiar with Fabry disease, terms used in the past might prevent the correct diagnosis of a potentially treatable disease.


Assuntos
Angioceratoma/diagnóstico , Doenças Cardiovasculares/diagnóstico , Doença de Fabry/diagnóstico , Parestesia/diagnóstico , Adulto , Estudos de Coortes , Diagnóstico Diferencial , Ecocardiografia Doppler , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dermatopatias/patologia , Terminologia como Assunto
16.
Eur J Echocardiogr ; 9(6): 831-2, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18492655

RESUMO

A 47-year-old woman was referred with increasing dyspnoea and neuropathic pain. During echocardiography, she showed the typical signs for a Fabry cardiomyopathy: global left ventricular function was normal with an ejection fraction of 65%. She had a concentric left ventricular hypertrophy with very prominent papillary muscles. In addition, the magnetic resonance tomography showed regional late enhancement in the postero-lateral wall which is the typical location of fibrosis in Fabry patients. She suffered from a genetically proven Fabry disease, and interestingly her family name is Mrs Fabry. Thus summarized, Mrs Fabry with a confirmed Fabry disease presented with a typically Fabry cardiomyopathy.


Assuntos
Doença de Fabry/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Aforismos e Provérbios como Assunto , Dispneia/etiologia , Doença de Fabry/complicações , Feminino , Humanos , Hipertrofia Ventricular Esquerda/etiologia , Pessoa de Meia-Idade , Dor/etiologia , Sensibilidade e Especificidade , Ultrassonografia
18.
Circulation ; 104(9): 1059-65, 2001 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-11524402

RESUMO

BACKGROUND: We sought to investigate ultrasonic strain rate and strain as new indices to quantify the contractile reserve of stunned myocardium during dobutamine infusion. METHODS AND RESULTS: Stunning of the left ventricular posterior wall was induced in 9 closed-chest pigs after 30 minutes of severe hypoperfusion followed by 60 minutes of reperfusion of the left circumflex coronary artery territory. A second group of 7 animals had no coronary occlusion and served as normal controls. An incremental dobutamine infusion protocol was used in both groups. Changes in regional radial function were monitored by use of ultrasound-derived maximal systolic radial strain rate (SR) and systolic strain (epsilon). In the control group, dobutamine induced an increase in both SR and maximal dP/dt, which correlated linearly (r=0.85). Conversely, epsilon values increased at low doses of dobutamine (2.5 to 5 microg. kg(-1). min(-1)) but decreased during higher infusion rates (10 to 20 microg. kg(-1). min(-1)). During circumflex hypoperfusion, SR and epsilon of the posterior wall decreased from 5.0+/-0.3 s(-1) and 63+/-6% to 2.9+/-0.3 s(-1) and 27+/-4%, respectively (P<0.01). After 60 minutes of reperfusion, SR and epsilon failed to fully resume because of stunning, averaging 3.6+/-0.2 s(-1) and 35+/-3%, respectively (P=0.12 versus ischemia, P<0.05 versus baseline). During dobutamine infusion, SR increased at 5 microg. kg(-1). min(-1) and exceeded baseline values at 20 microg. kg(-1). min(-1) (P<0.05), whereas epsilon increased only at high doses and remained below baseline levels (P<0.05). CONCLUSIONS: The changes in regional function of stunned myocardium during inotropic stimulation could be characterized by use of ultrasonic deformation parameters. During dobutamine infusion, strain-rate values quantified the contractile reserve better than strain values.


Assuntos
Ecocardiografia , Contração Miocárdica/fisiologia , Miocárdio Atordoado/diagnóstico por imagem , Animais , Cardiotônicos , Dobutamina , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Hemodinâmica/fisiologia , Masculino , Miocárdio Atordoado/fisiopatologia , Análise de Regressão , Suínos
19.
Cardiovasc Res ; 39(2): 401-12, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9798525

RESUMO

OBJECTIVE: The long-term effects and mechanisms of early started angiotensin converting enzyme (ACE) inhibition post myocardial infarction (MI) are not well understood. Chronic effects of early ACE inhibition on hemodynamics, left ventricular diastolic wall stress and remodeling were, therefore, compared to that of angiotensin AT1-receptor subtype blockade in rats with experimental myocardial infarction. The contribution of bradykinin potentiation to both ACE inhibitor and angiotensin AT1-receptor subtype blockade was assessed by cotreatment of rats with a bradykinin B2-receptor antagonist. METHODS: MI was produced by coronary artery ligation in adult male Wistar rats. The ACE inhibitor, quinapril (6 mg/kg per day), or the angiotensin AT1-receptor subtype blocker, losartan (10 mg/kg per day), administered by gavage, and the bradykinin B2-receptor antagonist, Hoe-140 (500 micrograms/kg per day s.c.), administered either alone or in combination with quinapril or losartan, were started 30 min after MI and continued for eight weeks. RESULTS: Quinapril and losartan reduced left ventricular end-diastolic pressure and global left ventricular diastolic wall stress only in rats with large MI. Pressure volume curves showed a rightward shift in proportion to MI size that was not prevented by quinapril or losartan treatment. Only the ACE inhibitor reduced left ventricular weight and this effect was prevented by cotreatment with the bradykinin antagonist. Baseline and peak cardiac index and stroke volume index, as determined using an electromagnetic flowmeter before and after an acute intravenous volume load, were restored by quinapril, whereas losartan had no effects. CONCLUSION: Treatments starting 30 min after coronary artery ligation, with either quinapril or losartan, reduced preload only in rats with large MI. Despite this unloading of the heart, structural dilatation was not prevented by this early treatment. Only quinapril improved cardiac performance and reduced left ventricular weight and this effect was abolished by cotreatment with Hoe-140, suggesting an angiotensin II blockade-independent, but bradykinin potentiation-dependent, mechanism.


Assuntos
Angiotensina I , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Isoquinolinas/uso terapêutico , Losartan/uso terapêutico , Infarto do Miocárdio/tratamento farmacológico , Tetra-Hidroisoquinolinas , Antagonistas Adrenérgicos beta/farmacologia , Análise de Variância , Angiotensina I/farmacologia , Animais , Bradicinina/análogos & derivados , Bradicinina/metabolismo , Bradicinina/farmacologia , Antagonistas dos Receptores da Bradicinina , Relação Dose-Resposta a Droga , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Hemodinâmica/efeitos dos fármacos , Hipertrofia Ventricular Esquerda/prevenção & controle , Masculino , Infarto do Miocárdio/metabolismo , Tamanho do Órgão/efeitos dos fármacos , Quinapril , Ratos , Ratos Wistar
20.
Ultrasound Med Biol ; 27(8): 1087-97, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11527595

RESUMO

Strain rate (SR) and strain (epsilon) have been proposed as new ultrasound (US) indices for quantifying regional wall deformation, and can be measured from color Doppler myocardial data by determining the local spatial velocity gradient. The aim of this study was to define normal regional SR/epsilon values for both radial and longitudinal myocardial deformation. SR/epsilon profiles were obtained from 40 healthy volunteers. For radial deformation, posterior left ventricular (LV) wall SR/epsilon were calculated. For longitudinal, they were determined for basal, mid- and apical segments of the 1. septum; 2. lateral, 3. posterior and 4. anterior LV walls and for the 5. right ventricular (RV) lateral wall. SR/epsilon values describing radial deformation were higher than the corresponding SR/epsilon values obtained for longitudinal deformation. Longitudinal SR/epsilon were homogeneous throughout the septum and all LV walls. This was in contrast to the normal base-apex velocity gradient. The RV segmental SR/epsilon values were higher than those obtained from the corresponding LV wall and inhomogeneous (higher in the apical segments). SR/epsilon imaging appears to be a robust technique for quantifying regional myocardial deformation.


Assuntos
Ecocardiografia Doppler em Cores , Contração Miocárdica , Adulto , Diástole , Feminino , Frequência Cardíaca , Humanos , Masculino , Reprodutibilidade dos Testes , Função Ventricular Esquerda , Função Ventricular Direita
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