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1.
Radiographics ; : 190148, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32004118

RESUMO

Endomyocardial fibrosis (EMF) affects approximately 12 million persons worldwide and is an important cause of restrictive cardiomyopathy in the developing world, with the highest prevalence reported in sub-Saharan Africa, South Asia, and South America. EMF is characterized by apical filling with fibrotic tissue of one or both ventricles, often associated with thrombus, calcification, and atrioventricular valve regurgitation, leading to typical symptoms of restrictive heart failure. Transthoracic echocardiography (TTE) is the first-line modality for assessment of EMF, basically owing to its widespread availability. However, in recent years cardiac MRI has emerged as a powerful tool for assessment of cardiac morphology and function, with higher accuracy than TTE, along with the unique advantage of being able to provide comprehensive noninvasive tissue characterization. Delayed enhancement (DE) imaging is the cornerstone of cardiac MRI tissue characterization and allows accurate identification of myocardial fibrosis, conveying valuable additional diagnostic and prognostic information. The typical DE pattern in EMF, described as the "double V" sign, consists of a three-layered pattern of normal myocardium, thickened enhanced endomyocardium, and overlying thrombus at the apex of the affected ventricle; it has excellent correlation with histopathologic findings and plays an important role in differentiating EMF from other cardiomyopathies. Conversely, fibrous tissue deposition quantified using DE imaging, when indexed to body surface area, has been shown to be a strong independent predictor of mortality. The aim of this review is to summarize state-of-the-art applications of cardiac MRI for diagnostic and prognostic assessment of patients with suspected or confirmed EMF. Online supplemental material is available for this article. ©RSNA, 2020.

2.
Magn Reson Imaging Clin N Am ; 27(3): 453-463, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31279449

RESUMO

Despite recent advancements in newer biomarkers development and improved imaging techniques, the diagnosis of cardiac amyloidosis (CA) remains a frequent clinical challenge. In this setting, cardiac MR (CMR) imaging has emerged as a powerful tool to assess heart morphology and function, with the unique advantage of noninvasive tissue characterization. This article summarizes the CMR imaging common findings in CA and the latest research in this field, including delayed enhancement, native T1 mapping, and extracellular volume quantification.


Assuntos
Amiloidose/diagnóstico por imagem , Cardiopatias/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Coração/diagnóstico por imagem , Humanos
3.
J Cardiovasc Magn Reson ; 21(1): 1, 2019 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-30612574

RESUMO

BACKGROUND: Phase contrast (PC) cardiovascular magnetic resonance (CMR) is widely employed for flow quantification, but analysis typically requires time consuming manual segmentation which can require human correction. Advances in machine learning have markedly improved automated processing, but have yet to be applied to PC-CMR. This study tested a novel machine learning model for fully automated analysis of PC-CMR aortic flow. METHODS: A machine learning model was designed to track aortic valve borders based on neural network approaches. The model was trained in a derivation cohort encompassing 150 patients who underwent clinical PC-CMR then compared to manual and commercially-available automated segmentation in a prospective validation cohort. Further validation testing was performed in an external cohort acquired from a different site/CMR vendor. RESULTS: Among 190 coronary artery disease patients prospectively undergoing CMR on commercial scanners (84% 1.5T, 16% 3T), machine learning segmentation was uniformly successful, requiring no human intervention: Segmentation time was < 0.01 min/case (1.2 min for entire dataset); manual segmentation required 3.96 ± 0.36 min/case (12.5 h for entire dataset). Correlations between machine learning and manual segmentation-derived flow approached unity (r = 0.99, p < 0.001). Machine learning yielded smaller absolute differences with manual segmentation than did commercial automation (1.85 ± 1.80 vs. 3.33 ± 3.18 mL, p < 0.01): Nearly all (98%) of cases differed by ≤5 mL between machine learning and manual methods. Among patients without advanced mitral regurgitation, machine learning correlated well (r = 0.63, p < 0.001) and yielded small differences with cine-CMR stroke volume (∆ 1.3 ± 17.7 mL, p = 0.36). Among advanced mitral regurgitation patients, machine learning yielded lower stroke volume than did volumetric cine-CMR (∆ 12.6 ± 20.9 mL, p = 0.005), further supporting validity of this method. Among the external validation cohort (n = 80) acquired using a different CMR vendor, the algorithm yielded equivalently small differences (∆ 1.39 ± 1.77 mL, p = 0.4) and high correlations (r = 0.99, p < 0.001) with manual segmentation, including similar results in 20 patients with bicuspid or stenotic aortic valve pathology (∆ 1.71 ± 2.25 mL, p = 0.25). CONCLUSION: Fully automated machine learning PC-CMR segmentation performs robustly for aortic flow quantification - yielding rapid segmentation, small differences with manual segmentation, and identification of differential forward/left ventricular volumetric stroke volume in context of concomitant mitral regurgitation. Findings support use of machine learning for analysis of large scale CMR datasets.


Assuntos
Aorta/diagnóstico por imagem , Valva Aórtica/diagnóstico por imagem , Cardiopatias/diagnóstico por imagem , Hemodinâmica , Aprendizado de Máquina , Imagem Cinética por Ressonância Magnética , Imagem de Perfusão do Miocárdio/métodos , Idoso , Aorta/fisiopatologia , Valva Aórtica/fisiopatologia , Automação , Velocidade do Fluxo Sanguíneo , Feminino , Cardiopatias/fisiopatologia , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudo de Prova de Conceito , Estudos Prospectivos , Reprodutibilidade dos Testes , Estudos Retrospectivos , Estados Unidos
6.
JAMA Cardiol ; 2(2): 190-199, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-27926769

RESUMO

Importance: In Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD), interventions reducing the progression of myocardial disease could affect survival. Objective: To assess the effect of early angiotensin-converting enzyme (ACE) inhibitor therapy in patients with normal left ventricular function on the progression of myocardial fibrosis (MF) identified on cardiovascular magnetic resonance (CMR). Design, Setting, and Participants: A randomized clinical trial conducted in 2 centers included 76 male patients with DMD or BMD undergoing 2 CMR studies with a 2-year interval for ventricular function and MF assessment. In a non-intent-to-treat trial, 42 patients with MF and normal left ventricular ejection fraction (LVEF) were randomized (1:1) to receive or not receive ACE inhibitor therapy. The study was conducted from June 26, 2009, to June 30, 2012. Data analysis was performed from June 30, 2013, to October 3, 2016. Interventions: Randomization (1:1) to receive or not receive ACE inhibitor therapy. Main Outcomes and Measures: Primary outcome was MF progression from baseline to the 2-year CMR study. Results: Of the 76 male patients included in the study, 70 had DMD (92%) and 6 had BMD (8%); mean (SD) age at baseline was 13.1 (4.4) years. Myocardial fibrosis was present in 55 patients (72%) and LV systolic dysfunction was identified in 13 patients (24%). Myocardial fibrosis at baseline was an independent indicator of lower LVEF at follow-up (coefficient [SE], -0.16 [0.07]; P = .03). Among patients with MF and preserved LVEF (42 [55%]), those randomized (21 patients in each arm) to receive ACE inhibitors demonstrated slower MF progression compared with the untreated group (mean [SD] increase of 3.1% [7.4%] vs 10.0% [6.2%] as a percentage of LV mass; P = .001). In multivariate analysis, ACE inhibitor therapy was an independent indicator of decreased MF progression (coefficient [SE], -4.51 [2.11]; P = .04). Patients with MF noted on CMR had a higher probability of cardiovascular events (event rate, 10 of 55 [18.2%] vs 0 of 21 [0%]; log-rank P = .04). Conclusions and Relevance: In this 2-year, follow-up, randomized clinical trial of patients with Duchenne or Becker muscular dystrophy whose LVEF was preserved and MF was present as determined on CMR, ACE inhibitor therapy was associated with significantly slower progression of MF. The presence of MF was associated with worse patient prognosis. Trial Registration: clinicaltrials.org Identifier: NCT02432885.


Assuntos
Cardiomiopatias/etiologia , Distrofia Muscular de Duchenne/complicações , Miocárdio/patologia , Sistema de Registros , Adolescente , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Biópsia , Cardiomiopatias/diagnóstico , Cardiomiopatias/tratamento farmacológico , Cardiomiopatias/fisiopatologia , Criança , Progressão da Doença , Feminino , Fibrose/diagnóstico , Fibrose/tratamento farmacológico , Fibrose/etiologia , Fibrose/fisiopatologia , Seguimentos , Humanos , Imagem Cinética por Ressonância Magnética , Masculino , Distrofia Muscular de Duchenne/diagnóstico , Prognóstico , Estudos Prospectivos , Volume Sistólico/fisiologia
7.
J Am Soc Echocardiogr ; 29(7): 679-88, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27086044

RESUMO

BACKGROUND: Chagas heart disease has a high socioeconomic burden, and any strategy to detect early myocardial damage is welcome. Speckle-tracking echocardiography assesses global and segmental left ventricular (LV) systolic function, yielding values of two-dimensional strain (ε). The aim of this study was to determine if patients with chronic Chagas disease and normal LV ejection fractions present abnormalities in global and segmental LV ε. METHODS: In this prospective study, patients with Chagas disease with no evidence of cardiac involvement (group I; n = 83) or at stage A of the cardiac form (i.e., with changes limited to the electrocardiogram) (group A; n = 42) and 43 control subjects (group C) underwent evaluation of global and segmental LV ε by speckle-tracking echocardiography. A subset of randomly selected patients in group A underwent cardiac magnetic resonance imaging and repeated echocardiography 3.5 ± 0.8 years after the first evaluation. RESULTS: Mean age, chamber dimensions, and LV ejection fraction were similar among the groups. Global longitudinal (group C, -19 ± 2%; group I, -19 ± 2%; group A, -19 ± 2%), circumferential (group C, -19 ± 3%; group I, -20 ± 3%; group A, -19 ± 3%), and radial (group C, 46 ± 10%; group I, 45 ± 13%; group A, 42 ± 14%) LV ε were similar among the groups. Segmental longitudinal, circumferential, and radial LV ε were similar across the studied groups. Seven of 14 patients had areas of fibrosis on cardiac magnetic resonance imaging. Patients with fibrosis had lower global longitudinal (-15 ± 2% vs -18 ± 2%, P = .004), circumferential (-14 ± 2% vs -19 ± 2%, P = .002), and radial LV ε (36 ± 13% vs 54 ± 12%, P = .02) than those without cardiac fibrosis despite similar LV ejection fractions. Patients with fibrosis had lower radial LV ε in the basal inferoseptal wall than patients without cardiac fibrosis (27 ± 17% vs 60 ± 15%, P = .04). CONCLUSIONS: Patients with chronic Chagas disease and normal global and segmental LV systolic function on two-dimensional echocardiography had global and segmental LV ε similar to that of control subjects. However, those in the early stages of the cardiac form and cardiac fibrosis had lower global longitudinal, circumferential, and radial LV ε.


Assuntos
Cardiomiopatia Chagásica/diagnóstico por imagem , Cardiomiopatia Chagásica/epidemiologia , Ecocardiografia/estatística & dados numéricos , Volume Sistólico , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/epidemiologia , Adulto , Brasil/epidemiologia , Comorbidade , Feminino , Humanos , Imagem Cinética por Ressonância Magnética/estatística & dados numéricos , Masculino , Prevalência , Reprodutibilidade dos Testes , Fatores de Risco , Sensibilidade e Especificidade
8.
Arq. bras. cardiol ; 104(2): 159-168, 02/2015. tab, graf
Artigo em Inglês | LILACS | ID: lil-741144

RESUMO

Background: Cardiac magnetic resonance imaging provides detailed anatomical information on infarction. However, few studies have investigated the association of these data with mortality after acute myocardial infarction. Objective: To study the association between data regarding infarct size and anatomy, as obtained from cardiac magnetic resonance imaging after acute myocardial infarction, and long-term mortality. Methods: A total of 1959 reports of “infarct size” were identified in 7119 cardiac magnetic resonance imaging studies, of which 420 had clinical and laboratory confirmation of previous myocardial infarction. The variables studied were the classic risk factors – left ventricular ejection fraction, categorized ventricular function, and location of acute myocardial infarction. Infarct size and acute myocardial infarction extent and transmurality were analyzed alone and together, using the variable named “MET-AMI”. The statistical analysis was carried out using the elastic net regularization, with the Cox model and survival trees. Results: The mean age was 62.3 ± 12 years, and 77.3% were males. During the mean follow-up of 6.4 ± 2.9 years, there were 76 deaths (18.1%). Serum creatinine, diabetes mellitus and previous myocardial infarction were independently associated with mortality. Age was the main explanatory factor. The cardiac magnetic resonance imaging variables independently associated with mortality were transmurality of acute myocardial infarction (p = 0.047), ventricular dysfunction (p = 0.0005) and infarcted size (p = 0.0005); the latter was the main explanatory variable for ischemic heart disease death. The MET-AMI variable was the most strongly associated with risk of ischemic heart disease death (HR: 16.04; 95%CI: 2.64-97.5; p = 0.003). Conclusion: The anatomical data of infarction, obtained from cardiac magnetic resonance imaging after acute myocardial infarction, were independently ...


Fundamento: A ressonância magnética cardíaca fornece informações anatômicas detalhadas do infarto, porém poucos estudos investigaram a associação desses dados com mortalidade pós-infarto agudo do miocárdio. Objetivo: Verificar a associação entre os dados de anatomia e magnitude do infarto, obtidos da ressonância magnética cardíaca pós-infarto agudo do miocárdio, e mortalidade em longo prazo. Métodos: Foram identificados 1.959 laudos com “massa infartada” em 7.119 exames de ressonância magnética cardíaca, dos quais 420 possuíam documentação clínica e laboratorial de infarto agudo do miocárdio prévio. As variáveis estudadas foram os fatores de risco clássicos, fração de ejeção do ventrículo esquerdo, função ventricular categorizada e localização do infarto agudo do miocárdio. Massa infartada, extensão e transmuralidade do infarto agudo do miocárdio foram analisadas de maneira isolada e conjuntamente, pela variável denominada “MET-IAM”. A análise estatística foi feita pelo elastic net regularization, pelo modelo de Cox e por árvores de sobrevida. Resultados: A idade média foi 62,3 ± 12 anos, sendo 77,3% de homens. Durante o seguimento de 6,4 ± 2,9 anos, foram identificados 76 óbitos (18,1%). Creatinina sérica, diabetes melito e infarto agudo do miocárdio prévio demonstraram associação independente com mortalidade. A idade foi o principal fator explicativo. As variáveis da ressonância magnética cardíaca que se associaram de forma independente com a mortalidade foram: transmuralidade do infarto agudo do miocárdio (p = 0,047), disfunção ventricular (p = 0,0005) e massa infartada (p = 0,0005) − sendo essa última a principal variável explicativa para morte por doença isquêmica cardíaca. A variável MET-IAM exibiu a maior associação de risco para morte por doença isquêmica cardíaca (HR: 16,04; IC95%: 2,64-97,5; p = 0,003). Conclusão: Os dados anatômicos do infarto obtidos da ressonância magnética cardíaca pós-infarto ...


Assuntos
Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Imagem por Ressonância Magnética/métodos , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/mortalidade , Causas de Morte , Determinação de Ponto Final , Métodos Epidemiológicos , Infarto do Miocárdio/fisiopatologia , Índice de Gravidade de Doença , Fatores de Tempo , Doenças Vasculares/mortalidade , Doenças Vasculares/fisiopatologia , Disfunção Ventricular Esquerda/fisiopatologia , Função Ventricular Esquerda/fisiologia
9.
Arq Bras Cardiol ; 104(2): 159-68, 2015 Feb.
Artigo em Inglês, Português | MEDLINE | ID: mdl-25424161

RESUMO

BACKGROUND: Cardiac magnetic resonance imaging provides detailed anatomical information on infarction. However, few studies have investigated the association of these data with mortality after acute myocardial infarction. OBJECTIVE: To study the association between data regarding infarct size and anatomy, as obtained from cardiac magnetic resonance imaging after acute myocardial infarction, and long-term mortality. METHODS: A total of 1959 reports of "infarct size" were identified in 7119 cardiac magnetic resonance imaging studies, of which 420 had clinical and laboratory confirmation of previous myocardial infarction. The variables studied were the classic risk factors - left ventricular ejection fraction, categorized ventricular function, and location of acute myocardial infarction. Infarct size and acute myocardial infarction extent and transmurality were analyzed alone and together, using the variable named "MET-AMI". The statistical analysis was carried out using the elastic net regularization, with the Cox model and survival trees. RESULTS: The mean age was 62.3 ± 12 years, and 77.3% were males. During the mean follow-up of 6.4 ± 2.9 years, there were 76 deaths (18.1%). Serum creatinine, diabetes mellitus and previous myocardial infarction were independently associated with mortality. Age was the main explanatory factor. The cardiac magnetic resonance imaging variables independently associated with mortality were transmurality of acute myocardial infarction (p = 0.047), ventricular dysfunction (p = 0.0005) and infarcted size (p = 0.0005); the latter was the main explanatory variable for ischemic heart disease death. The MET-AMI variable was the most strongly associated with risk of ischemic heart disease death (HR: 16.04; 95%CI: 2.64-97.5; p = 0.003). CONCLUSION: The anatomical data of infarction, obtained from cardiac magnetic resonance imaging after acute myocardial infarction, were independently associated with long-term mortality, especially for ischemic heart disease death.


Assuntos
Imagem por Ressonância Magnética/métodos , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/mortalidade , Idoso , Idoso de 80 Anos ou mais , Causas de Morte , Determinação de Ponto Final , Métodos Epidemiológicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/fisiopatologia , Índice de Gravidade de Doença , Fatores de Tempo , Doenças Vasculares/mortalidade , Doenças Vasculares/fisiopatologia , Disfunção Ventricular Esquerda/fisiopatologia , Função Ventricular Esquerda/fisiologia
10.
Arq. bras. cardiol ; 103(6,supl.3): 1-86, 12/2014. tab
Artigo em Português | LILACS | ID: lil-732178
11.
Int J Cardiol ; 177(2): 385-91, 2014 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-25281436

RESUMO

BACKGROUND: Multi-detector computed tomography angiography (MDCTA) is a promising method for risk assessment of patients with acute chest pain. However, its diagnostic performance in higher-risk patients has not been investigated in a large international multicenter trial. Therefore, in the present study we sought to estimate the diagnostic accuracy of MDCTA to detect significant coronary stenosis in patients with acute coronary syndrome (ACS). METHODS: Patients included in the CORE64 study were categorized as suspected-ACS or non-ACS based on clinical data. A 64-row coronary MDCTA was performed before invasive coronary angiography (ICA) and both exams were evaluated by blinded, independent core laboratories. RESULTS: From 371 patients included, 94 were categorized as suspected ACS and 277 as non-ACS. Patient-based analysis showed an area under the receiver-operating-characteristic curve (AUC) for detecting ≥ 50% coronary stenosis of 0.95 (95% CI: 0.88-0.98) in ACS and 0.92 (95% CI: 0.88-0.95) in non-ACS group (P=0.29). The sensitivity, specificity, positive and negative predictive values of MDCTA were 0.90(0.80-0.96), 0.88(0.70-0.98), 0.95(0.87-0.99) and 0.77(0.58-0.90) in suspected ACS patients and 0.87(0.81-0.92), 0.86(0.79-0.92), 0.91(0.85-0.95) and 0.82(0.74-0.89) in non-ACS patients (P NS for all comparisons). The mean calcium scores (CS) were 282 ± 449 in suspected ACS and 435 ± 668 in non-ACS group. The accuracy of CS to detect significant coronary stenosis was only moderate and the absence or minimal coronary artery calcification could not exclude the presence of significant coronary stenosis, particularly in ACS patients. CONCLUSIONS: The diagnostic accuracy of MDCTA to detect significant coronary stenosis is high and comparable for both ACS and non-ACS patients.


Assuntos
Síndrome Coronariana Aguda/diagnóstico por imagem , Doença da Artéria Coronariana/diagnóstico por imagem , Estenose Coronária/diagnóstico por imagem , Internacionalidade , Tomografia Computadorizada Multidetectores/normas , Síndrome Coronariana Aguda/epidemiologia , Idoso , Doença da Artéria Coronariana/epidemiologia , Estenose Coronária/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
13.
Open Cardiovasc Med J ; 8: 26-34, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24847387

RESUMO

INTRODUCTION: In recent years, high-resolution magnetic resonance imaging (MRI) has emerged as a very promising technique for studying atherosclerotic disease in humans. AIM: In the present study we sought to determine whether MRI allowed for the morphological characterization of the coronary vessel wall and atherosclerotic plaques using histopathological assessment as the reference standard. METHODS: The study population consisted of 13 patients who died of acute myocardial infarction and underwent autopsy. The proximal portions of the coronary arteries were excised and were evaluated both by MRI and by histopathology. For each arterial segment, the following parameters were calculated through manual planimetry: 1. total vessel area (TVA); 2. luminal area (LA) and 3. plaque area (PA). RESULTS: A total of 207 coronary artery cross-sections were found to be suitable for analysis by both MRI and histopathology and were included in the final analyses. Both methods demonstrated moderate to good agreement for the quantification of TVA (mean difference = 2.4±2.4 mm(2), 95‰ limits of agreement from -2.4 to +7.2 mm(2); CCC = 0.69, 95‰ CI from 0.63 to 0.75), LA (mean difference = 0.0±1.7 mm(2), 95‰ limits of agreement from -3.3 to + 3.3 mm(2); CCC = 0.84, 95‰ CI from 0.80 to 0.88) and PA (mean difference = 2.4±2.4 mm(2), 95‰ limits of agreement from -2.3 to + 7.1 mm(2); CCC = 0.64, 95‰ CI from 0.58 to 0.71). CONCLUSION: In this ex vivo experimental model we demonstrated good agreement between coronary artery morphometrical measurements obtained by high-resolution MRI and by histopathology.

14.
Arq Bras Cardiol ; 103(6 Suppl 3): 1-86, 2014 Dec.
Artigo em Português | MEDLINE | ID: mdl-25594284
19.
Arq. bras. cardiol ; 99(6): 1149-1155, dez. 2012. graf, tab
Artigo em Português | LILACS | ID: lil-662369

RESUMO

FUNDAMENTO: A ressonância magnética cardíaca é considerada o método padrão-ouro para o cálculo de volumes cardíacos. A bioimpedância transtorácica cardíaca avalia o débito cardíaco. Não há trabalhos que validem essa medida comparada à ressonância. OBJETIVO: Avaliar o desempenho da bioimpedância transtorácica cardíaca no cálculo do débito cardíaco, índice cardíaco e volume sistólico, utilizando a ressonância como padrão-ouro. MÉTODOS: Avaliados 31 pacientes, com média de idade de 56,7 ± 18 anos, sendo 18 (58%) do sexo masculino. Foram excluídos os pacientes cuja indicação para a ressonância magnética cardíaca incluía avaliação sob estresse farmacológico. A correlação entre os métodos foi avaliada pelo coeficiente de Pearson, e a dispersão das diferenças absolutas em relação à média foi demonstrada pelo método de Bland-Altman. A concordância entre os métodos foi realizada pelo coeficiente de correlação intraclasses. RESULTADOS: A média do débito cardíaco pela bioimpedância transtorácica cardíaca e pela ressonância foi, respectivamente, 5,16 ± 0,9 e 5,13 ± 0,9 L/min. Observou-se boa correlação entre os métodos para o débito cardíaco (r = 0,79; p = 0,0001), índice cardíaco (r = 0,74; p = 0,0001) e volume sistólico (r = 0,88; p = 0,0001). A avaliação pelo gráfico de Bland-Altman mostrou pequena dispersão das diferenças em relação à média, com baixa amplitude dos intervalos de concordância. Houve boa concordância entre os dois métodos quando avaliados pelo coeficiente de correlação intraclasses, com coeficientes para débito cardíaco, índice cardíaco e volume sistólico de 0,78, 0,73 e 0,88, respectivamente (p < 0,0001 para todas as comparações). CONCLUSÃO: A bioimpedância transtorácica cardíaca mostrou-se acurada no cálculo do débito cardíaco quando comparada à ressonância magnética cardíaca.


BACKGROUND: Cardiac magnetic resonance imaging is considered the gold-standard method for the calculation of cardiac volumes. Transthoracic impedance cardiography assesses the cardiac output. No studies validating this measurement, in comparison to that obtained by magnetic resonance imaging, are available. OBJECTIVE: To evaluate the performance of transthoracic impedance cardiography in the calculation of the cardiac output, cardiac index and stroke volume using magnetic resonance imaging as the gold-standard. METHODS: 31 patients with a mean age of 56.7 ± 18 years were assessed; of these, 18 (58%) were males. Patients whose indication for magnetic resonance imaging required pharmacologic stress test were excluded. Correlation between methods was assessed using the Pearson's coefficient, and dispersion of absolute differences in relation to the mean was demonstrated using the Bland-Altman's method. Agreement between methods was analyzed using the intraclass correlation coefficient. RESULTS: The mean cardiac output by transthoracic impedance cardiography and by magnetic resonance imaging was 5.16 ± 0.9 and 5.13 ± 0.9 L/min, respectively. Good agreement between methods was observed for cardiac output (r = 0.79; p = 0.0001), cardiac index (r = 0.74; p = 0.0001) and stroke volume (r = 0.88; p = 0.0001). The analysis by the Bland-Altman plot showed low dispersion of differences in relation to the mean, with a low amplitude of agreement intervals. Good agreement between the two methods was observed when analyzed by the intraclass correlation coefficient, with coefficients for cardiac output, cardiac index and stroke volume of 0.78, 0.73 and 0.88, respectively (p < 0.0001 for all comparisons). CONCLUSION: Transthoracic impedance cardiography proved accurate in the calculation of the cardiac output in comparison to cardiac magnetic resonance imaging.


Assuntos
Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Débito Cardíaco/fisiologia , Cardiografia de Impedância/normas , Imagem por Ressonância Magnética/normas , Insuficiência Cardíaca/diagnóstico , Hemodinâmica/fisiologia , Volume Sistólico
20.
Arq Bras Cardiol ; 99(6): 1149-55, 2012 Dec.
Artigo em Inglês, Português | MEDLINE | ID: mdl-23152290

RESUMO

BACKGROUND: Cardiac magnetic resonance imaging is considered the gold-standard method for the calculation of cardiac volumes. Transthoracic impedance cardiography assesses the cardiac output. No studies validating this measurement, in comparison to that obtained by magnetic resonance imaging, are available. OBJECTIVE: To evaluate the performance of transthoracic impedance cardiography in the calculation of the cardiac output, cardiac index and stroke volume using magnetic resonance imaging as the gold-standard. METHODS: 31 patients with a mean age of 56.7 ± 18 years were assessed; of these, 18 (58%) were males. Patients whose indication for magnetic resonance imaging required pharmacologic stress test were excluded. Correlation between methods was assessed using the Pearson's coefficient, and dispersion of absolute differences in relation to the mean was demonstrated using the Bland-Altman's method. Agreement between methods was analyzed using the intraclass correlation coefficient. RESULTS: The mean cardiac output by transthoracic impedance cardiography and by magnetic resonance imaging was 5.16 ± 0.9 and 5.13 ± 0.9 L/min, respectively. Good agreement between methods was observed for cardiac output (r = 0.79; p = 0.0001), cardiac index (r = 0.74; p = 0.0001) and stroke volume (r = 0.88; p = 0.0001). The analysis by the Bland-Altman plot showed low dispersion of differences in relation to the mean, with a low amplitude of agreement intervals. Good agreement between the two methods was observed when analyzed by the intraclass correlation coefficient, with coefficients for cardiac output, cardiac index and stroke volume of 0.78, 0.73 and 0.88, respectively (p < 0.0001 for all comparisons). CONCLUSION: Transthoracic impedance cardiography proved accurate in the calculation of the cardiac output in comparison to cardiac magnetic resonance imaging.


Assuntos
Débito Cardíaco/fisiologia , Cardiografia de Impedância/normas , Imagem por Ressonância Magnética/normas , Adulto , Idoso , Feminino , Insuficiência Cardíaca/diagnóstico , Hemodinâmica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Volume Sistólico
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