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1.
AJNR Am J Neuroradiol ; 42(2): 247-254, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33384294

RESUMO

BACKGROUND AND PURPOSE: Artificial intelligence algorithms have the potential to become an important diagnostic tool to optimize stroke workflow. Viz LVO is a medical product leveraging a convolutional neural network designed to detect large-vessel occlusions on CTA scans and notify the treatment team within minutes via a dedicated mobile application. We aimed to evaluate the detection accuracy of the Viz LVO in real clinical practice at a comprehensive stroke center. MATERIALS AND METHODS: Viz LVO was installed for this study in a comprehensive stroke center. All consecutive head and neck CTAs performed from January 2018 to March 2019 were scanned by the algorithm for detection of large-vessel occlusions. The system results were compared with the formal reports of senior neuroradiologists used as ground truth for the presence of a large-vessel occlusion. RESULTS: A total of 1167 CTAs were included in the study. Of these, 404 were stroke protocols. Seventy-five (6.4%) patients had a large-vessel occlusion as ground truth; 61 were detected by the system. Sensitivity was 0.81, negative predictive value was 0.99, and accuracy was 0.94. In the stroke protocol subgroup, 72 (17.8%) of 404 patients had a large-vessel occlusion, with 59 identified by the system, showing a sensitivity of 0.82, negative predictive value of 0.96, and accuracy of 0.89. CONCLUSIONS: Our experience evaluating Viz LVO shows that the system has the potential for early identification of patients with stroke with large-vessel occlusions, hopefully improving future management and stroke care.


Assuntos
Transtornos Cerebrovasculares/diagnóstico por imagem , Interpretação de Imagem Assistida por Computador/métodos , Aplicativos Móveis , Redes Neurais de Computação , Acidente Vascular Cerebral/diagnóstico por imagem , Idoso , Transtornos Cerebrovasculares/complicações , Angiografia por Tomografia Computadorizada/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Acidente Vascular Cerebral/etiologia
2.
J Hosp Infect ; 65(2): 163-8, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17174448

RESUMO

Following 183 ultrasound examinations, a randomized trial was conducted to compare three procedures for disinfection of probes under routine conditions: dry wiping with a soft, dry, non-sterile paper towel, antiseptic wiping with a towel impregnated with disinfectant spray and dry wiping followed by a 10 min ultraviolet C (UVC) cycle in a disinfection chamber. After ultrasonography, swabs were taken from transducer heads before and after cleaning and streaked onto plates that were then cultured. The number of colonies per plate was counted and organisms identified. The median microbial reduction was 100% for UVC, 98.4% for antiseptic wiping and 87.5% for dry wiping (P<0.001). The percentage of negative specimens was 88% for UVC, 16% for antiseptic wiping and 4% for dry wiping (P<0.0001). Microbial flora was isolated from 12 probes (6.6%) before cleaning, whereas specimens obtained after cleaning contained no pathogens except in one case after antiseptic wiping. UVC disinfection of ultrasound probe may provide a useful method for reducing the bacterial load under routine conditions.


Assuntos
Infecção Hospitalar/prevenção & controle , Desinfecção/métodos , Ultrassonografia/instrumentação , Raios Ultravioleta , Adulto , Idoso , Infecção Hospitalar/microbiologia , Infecção Hospitalar/transmissão , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Ultrassonografia/métodos , Ultrassonografia/normas
3.
Arch Mal Coeur Vaiss ; 99(11): 969-74, 2006 Nov.
Artigo em Francês | MEDLINE | ID: mdl-17181035

RESUMO

Echocardiography of athletes focuses on the left ventricle: in many cases, the interpretation is difficult, showing features of either dilated of hypertrophic cardiomyopathy. Accurate analysis requires careful recording of the left ventricle in the fundamental mode. Diagnostic errors by excess are common: overestimation of the chamber size (inadequate incidence), overestimation of wall thickness (failure to recognise right ventricular bands or false tendons). The body size of the individual must be considered when interpreting the chamber dimensions. The diastolic left ventricular dimension is often < 60 mm but it may attain 70 mm. In these cases, left ventricular function must be accurately determined and shown to be normal, which may prove difficult as the resting left ventricular ejection fraction is physiologically lower in trained athletes. The use of stress echo (exercise left ventricular ejection fraction) and Doppler tissue imaging (left ventricular filling) are often indispensable. Left ventricular wall thickness is rarely > 13 mm. a situation where the possibility of hypertrophic cardiomyopathy has to be assessed. Left atrial dilatation is inconstant and aortic root dilatation is very unusual. The right heart chambers are usually globally dilated and the inferior vena cava may seem abnormally dilated.


Assuntos
Ventrículos do Coração/diagnóstico por imagem , Esportes/fisiologia , Função Ventricular Esquerda/fisiologia , Cardiomiopatia Dilatada/diagnóstico por imagem , Cardiomiopatia Hipertrófica/diagnóstico por imagem , Humanos , Ultrassonografia
4.
Arch Mal Coeur Vaiss ; 99 Spec No 1(1): 7-14, 2006 Jan.
Artigo em Francês | MEDLINE | ID: mdl-16479958

RESUMO

Echocardiography continues to evolve in several directions: on the technical front, various tools are being developed and real time 3D is starting to find a place in routine practice as much as contrast is used unequally depending on the country. On the diagnostic front, certain aspects have been particularly emphasised this year: The key role of quantification of valvulopathies in order to guide management, both at rest and on effort. The place of echocardiography in asynchronism, even if a more consensual strategy is needed to take into account the different approaches. The very good prognostic series on stress echography in the context of myocardial ischaemia. Advances in the evaluation of filling pressures have allowed a better definition of the limits, and have refined the understanding of so-called 'diastolic' cardiac failure. Finally, the role of echography to guide and also evaluate the results of foramen ovale or interatrial communication closure.


Assuntos
Ecocardiografia/tendências , Estimulação Cardíaca Artificial , Meios de Contraste , Ecocardiografia/métodos , Comunicação Interatrial/diagnóstico por imagem , Comunicação Interatrial/cirurgia , Doenças das Valvas Cardíacas/diagnóstico por imagem , Ventrículos do Coração/diagnóstico por imagem , Humanos , Imageamento Tridimensional , Editoração/tendências , Função Ventricular Esquerda
5.
AJNR Am J Neuroradiol ; 42(7): E47, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34016585
6.
Arch Mal Coeur Vaiss ; 98(4): 325-30, 2005 Apr.
Artigo em Francês | MEDLINE | ID: mdl-15881849

RESUMO

Assessment of left ventricular filling pressures is now part of routine echocardiographic examination. It is a semi-quantitative evaluation usually based on analysis of transmitral blood flow. Restrictive type flow associated with poor left ventricular contraction is pathognomonic of increased left ventricular filling pressure: conversely, inversion of the mitral flow velocities is generally reassuring except in the presence of left ventricular hypertrophy. In other cases, it is necessary to complete the analysis with indices of left ventricular relaxation. The authors discuss the advantages of pulsed Doppler tissue imaging at the mitral ring over the propagation velocity in colour M-mode, especially when left ventricular contraction is normal or relatively preserved. In particular, the reproducibility of propagation velocity measurements is poor when the velocities are relatively high (> 50 cm/s) because a small error in measurement at these velocities has large repercussion on the value of the slope. Pulmonary vein flow, reputedly difficult to analyse, may be very valuable. Discordance of the different indices is one of the most difficult daily problems to resolve. However, it is possible to give a reliable "normal filling pressures" or "increased filling pressures" conclusion in over 80% of cases. Echocardiography cannot provide a precise study of diastole and terms such as abnormal relaxation, abnormal compliance or diastolic dysfunction should be avoided.


Assuntos
Ecocardiografia Doppler/métodos , Função Ventricular Esquerda/fisiologia , Humanos , Pressão , Fluxo Sanguíneo Regional
7.
Arch Mal Coeur Vaiss ; 98 Spec No 1: 39-46, 2005 Jan.
Artigo em Francês | MEDLINE | ID: mdl-15714862

RESUMO

What major trends can we single out from the large amount of literature that appeared in 2004? The role of echography in the investigation of asynchronism has most certainly been better defined. Real time 3D echography, now routinely available, has started to gain respect in different pathologies. The place of filling pressure evaluation in patients' management, as much diagnostic as therapeutic, has again been refined. The prognostic contribution of stress echography has been emphasized in particular this year. Despite a still limited routine role, publications regarding contrast techniques have been quite numerous: not only diagnostic contrast echography, but also contrast and pleiotropic gene transfer in the myocardium. The study of coronary reserve via the transthoracic route, possibly assisted with contrast, should become established as a routine technique.


Assuntos
Ecocardiografia , Meios de Contraste , Ecocardiografia/métodos , Ecocardiografia/tendências , Ecocardiografia sob Estresse , Humanos
8.
Hypertension ; 25(4 Pt 1): 651-9, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7721411

RESUMO

The aim of this study was to determine the relationship between the lumen diameter and function of the common carotid artery, a vessel representative of the capacitance portion of the circulation, and the different patterns of left ventricular hypertrophy in uncomplicated essential hypertensive patients. Carotid luminal diastolic cross-sectional area, distensibility, and compliance were derived from measurements by a high-definition echotracking system. Left ventricular dimensions were from echocardiography. The 86 hypertensive patients included 31 who had never been treated (group 1), 31 in whom treatment had been stopped for at least 2 weeks (group 2), and 24 treated patients (group 3). In multivariate analysis of the population as a whole, the following relations were statistically independent of age, blood pressure, gender, and group: Left ventricular end-diastolic volume index was positively correlated to carotid luminal cross-sectional area (r = .46, P < .0001) and compliance (r = .47, P < .0001); left ventricular mean wall thickness and mass-volume ratio were negatively correlated to distensibility (r = -.68, P < .0001; r = -.46, P < .0001, respectively) and compliance (r = -.40, P < .0001; r = -.37; P < .001, respectively); and left ventricular mass index was positively correlated to luminal cross-sectional area (r = .23, P < .02) and negatively to distensibility (r = -.26, P < .01). These results indicate that geometric and functional changes in the common carotid artery accompany geometric changes in the left ventricle. More specifically, they suggest that a reduction in distensibility paralleled cardiac concentric hypertrophy and remodeling, whereas an increase in arterial volume paralleled increased left ventricular cavity size.


Assuntos
Artérias Carótidas/diagnóstico por imagem , Hipertensão/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Adulto , Idoso , Pressão Sanguínea , Ecocardiografia , Feminino , Humanos , Hipertensão/complicações , Hipertrofia Ventricular Esquerda/complicações , Masculino , Pessoa de Meia-Idade , Análise Multivariada
9.
J Hypertens ; 17(6): 817-24, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10459880

RESUMO

OBJECTIVE: To determine whether the decision to treat uncomplicated mild hypertension with drugs, in accordance with the World Health Organization - International Society of Hypertension (WHO/ISH) guidelines based on a series of blood pressure (BP) measurements over 6 months, resulted in the treatment of patients at high risk on the basis of echocardiography. METHODS: One hundred and eighteen patients with mild hypertension (diastolic blood pressure 90-105 mm Hg and/or systolic blood pressure 140-180 mm Hg) were examined by echocardiography at inclusion and followed up for 6 months by a single physician unaware of the echographic results. RESULTS: Drug treatment was given to 48 patients, and 70 remained untreated. Treated patients had higher echographic indices than untreated patients (all P<0.05): left ventricular (LV) mass/body surface area (83.0+/-15.6 versus 75.3+/-14.8 g/m2), inter-ventricular septal thickness (9.7+/-1.7 versus 8.5+/-1.3 mm), LV posterior wall thickness (8.4+/-1.1 versus 7.8+/-1.1 mm), relative wall thickness (0.37+/-0.06 versus 0.34+/-0.06). LV geometry was normal in 98 patients, and 20 had LV concentric remodelling. The 10-year coronary disease risk (Framingham equation) was higher in the 20 patients with concentric remodelling than in those with normal LV geometry (10.4 versus 4.2%; P<0.005). Nine of these 20 patients were still untreated at the end of the 6-month follow-up period. CONCLUSION: Rigorous application of the WHO/ISH clinical guidelines in a group of mild hypertensive patients led to the treatment of patients with slightly higher LV mass and more concentric LV geometry than were found in those not treated. However, a high-risk subgroup, with concentric remodelling, was not identified and left untreated.


Assuntos
Ecocardiografia , Ventrículos do Coração/diagnóstico por imagem , Hipertensão/diagnóstico por imagem , Guias de Prática Clínica como Assunto , Adulto , Anti-Hipertensivos/uso terapêutico , Pressão Sanguínea , Eletrocardiografia , Feminino , Seguimentos , Humanos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/etiologia , Hipertrofia Ventricular Esquerda/prevenção & controle , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Sociedades Médicas , Remodelação Ventricular , Organização Mundial da Saúde
10.
J Hypertens ; 19(11): 2055-61, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11677372

RESUMO

OBJECTIVE: Doppler echocardiography was used to define reference values and determinants of tricuspid regurgitation peak velocity (TRV) in hypertensive patients. A TRV value > 2.5 m/s is the threshold usually defining abnormal right ventricular systolic pressure. DESIGN AND PATIENTS: Doppler echocardiography was performed in 320 consecutive uncomplicated hypertensive patients, without overt pulmonary or heart disease. Doppler echocardiography included LV mass measurement, LV inflow and pulmonary venous flow analysis, LV systolic function and TRV measurements. RESULTS: Among 320 patients, 255 had normal TRV < 2.5 m/s and 65 had elevated TRV > or = 2.5 m/s. Compared with the normal TRV group, the elevated TRV group was older (60 versus 50 years, P < 0.0001), systolic blood pressure was higher (156 versus 151 mmHg, P = 0.02) and antihypertensive therapy was more frequent (68 versus 51%, P = 0.02); indexed LV mass was higher (45.4 versus 40.6 g/m2.7, P = 0.001), pulmonary D wave peak velocity was higher (42 versus 38 cm/s, P = 0.03). In univariate analysis, age was the most predictive variable of TRV (r = 0.36). In multivariate analysis, three variables were independently related to TRV: age, LV mass, pulmonary D wave (multiple r = 0.47). CONCLUSION: In mild hypertension, TRV is independently related to age, and to a lesser extent, to LV morphology and LV filling pressure. In clinical practice, age should be taken into account to interpret TRV.


Assuntos
Pressão Sanguínea , Hipertensão/fisiopatologia , Função Ventricular Direita , Envelhecimento/fisiologia , Velocidade do Fluxo Sanguíneo , Estudos Transversais , Diástole , Ecocardiografia Doppler , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sístole , Insuficiência da Valva Tricúspide/diagnóstico por imagem , Insuficiência da Valva Tricúspide/fisiopatologia
11.
Am J Cardiol ; 77(9): 739-44, 1996 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-8651126

RESUMO

Easily applicable, clinically relevant electrocardiographic criteria are needed to screen large populations for left ventricular (LV) hypertrophy. The aim of this study was to evaluate, in a population of 380 hypertensive patients of both sexes, whether obesity modified the diagnostic performance of Sokolow-Lyon and Cornell voltage criteria by comparing them with echocardiographic evaluations using different indexation methods for LV mass presentation (body surface area and various powers of the height variable). For the population as a whole, Cornell voltage was better correlated to LV mass than was Sokolow-Lyon voltage (r = 0.48 and 0.36, respectively). The poorest performance of Sokolow-Lyon voltage was observed among obese patients (best r = 0.1 and 0.21 in obese women and men, respectively). Sensitivities were assessed at a 95% specificity level. In nonobese patients, using sex-adjusted voltage values (43 and 36 mm in men and women, respectively, for Sokolow-Lyon voltage, and 28 and 25 mm for Cornell voltage), the sensitivities of Cornell voltage and Sokolow-Lyon voltage were similar in men and women (near 22% and 36%, respectively), whatever the indexation method used for LV mass. In obese patients, Cornell voltage sensitivity was similar to that of nonobese patients, whereas Sokolow-Lyon voltage had a much poorer sensitivity (<10%). For simple LV hypertrophy detection criteria, Sokolow-Lyon voltage should be avoided in obese hypertensive patients and replaced by the Cornell voltage criteria, which are not influenced by the presence of obesity.


Assuntos
Eletrocardiografia/métodos , Hipertrofia Ventricular Esquerda/diagnóstico , Obesidade/complicações , Índice de Massa Corporal , Superfície Corporal , Ecocardiografia , Feminino , Humanos , Hipertensão/complicações , Hipertensão/fisiopatologia , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/fisiopatologia , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Obesidade/fisiopatologia , Curva ROC , Sensibilidade e Especificidade , Fatores Sexuais
12.
Am J Cardiol ; 75(7): 498-502, 1995 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-7863997

RESUMO

Left ventricular (LV) hypertrophy is diagnosed on the basis of LV mass measurement at echocardiography. However, various thresholds for defining LV hypertrophy have been published, ranging from 111 to 134 g/m2 and from 100 to 125 g/m2 in men and women, respectively. The aim of our study was to evaluate variations in the prevalence of LV hypertrophy induced by the application of different threshold values among hypertensive subjects. LV mass was calculated in 349 hypertensive patients from an M-mode LV tracing obtained by left parasternal view in 83% and by subcostal view in 17% of patients. The prevalence of LV hypertrophy ranged from 17% to 39%, according to the threshold value applied (from 10% to 47%, and from 19% to 39% in women and men, respectively). As expected, the prevalence of LV hypertrophy in obese patients of both sexes was higher when applying the usual height-indexed threshold (143 and 102 g/m for men and women, respectively) than when applying the usual body surface area-indexed threshold (134 and 110 g/m2 for men and women, respectively). The use of normalized thresholds when comparing different indexation methods (in this case, 145 g/m for men, 120 g/m for women) will minimize these variations in part due to the threshold choice. Considering the clinical and therapeutic implications associated with the presence of LV hypertrophy, better standardization of definitions is needed; this could be based either on better-designed cooperative normality studies or meta-analysis of risk stratification.


Assuntos
Ecocardiografia , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Adulto , Idoso , Estatura , Superfície Corporal , Feminino , Humanos , Hipertensão/complicações , Hipertrofia Ventricular Esquerda/complicações , Masculino , Pessoa de Meia-Idade , Obesidade/complicações
13.
Am J Cardiol ; 72(7): 620-4, 1993 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-8362780

RESUMO

In some patients, left ventricular (LV) mass cannot be evaluated by M-mode echocardiography because the parasternal long-axis view is not available. The aim of this study was to determine whether the subcostal view obtained by M-mode echocardiography under 2-dimensional guidance allows accurate and reproducible LV mass determination. Using the cube formula, LV mass was calculated, from parasternal and subcostal views in 96 subjects: 73 hypertensives and 23 professional bicyclists, covering a wide range of LV dimensions. M-mode tracings were read by 2 experienced echocardiographers and the interobserver variability was evaluated. With use of the subcostal view, the interobserver reproducibility, expressed as observer 1-observer 2, was excellent: -0.3 +/- 1.3 mm for LV diastolic diameter, -0.1 +/- 1.0 mm for ventricular diastolic septal thickness, 0.2 +/- 0.6 mm for diastolic free wall thickness and 0.03 +/- 16.7 g for LV mass. In 96% of cases, the difference in LV mass between the 2 observers did not exceed 30 g. With use of the parasternal and subcostal approaches, LV mass was not statistically different (202.6 +/- 2.2 g and 206.5 +/- 2.0 g, respectively) and the difference was < 52 g (clinically significant threshold) in 91 of 96 cases. It is concluded that, using the cube formula, LV mass calculation based on the subcostal view was accurate and not statistically different from that provided by the usual parasternal approach.


Assuntos
Ciclismo , Ecocardiografia/métodos , Hipertensão/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Adulto , Ecocardiografia/instrumentação , Ecocardiografia/estatística & dados numéricos , Feminino , Ventrículos do Coração/diagnóstico por imagem , Humanos , Hipertensão/epidemiologia , Hipertrofia Ventricular Esquerda/epidemiologia , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes
15.
Am J Cardiol ; 75(7): 425-30, 1995 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-7863983

RESUMO

To test the hypothesis that flow characteristics from pulmonary regurgitation (PR) can predict right ventricular (RV) involvement in patients with inferior wall acute myocardial infarction, we prospectively recorded continuous-wave Doppler tracings and right-sided cardiac hemodynamics in 48 consecutive patients with inferior wall acute myocardial infarction and PR. Right heart hemodynamics enabled the identification of 29 patients with (group 1) and 19 without (group 2) RV involvement. In patients with RV involvement, the pulmonary regurgitant flow pattern was characterized by a rapid rise in flow velocity to a peak level followed by an abrupt deceleration in mid-diastole, whereas in patients without RV involvement, the deceleration in mid-diastole was gradual. The pressure half-time of PR (PHTPR) and the lowest mid-diastolic to peak early diastolic velocity ratio were significantly lower in group 1 than in group 2 (91 +/- 31 vs 214 +/- 57 ms [p < 0.001], 0.35 +/- 0.08 vs 0.59 +/- 0.13 [p < 0.001], respectively). The best diagnostic accuracy (95%) was obtained with cut-off values of PHTPR < or = 150 ms and the lowest mid-diastolic to peak early diastolic velocity ratio < or = 0.5: sensitivity 100%, specificity 89%, positive predictive value 94%, and negative predictive value 100%. Using multiple logistic regression analysis, we found that PHTPR was the strongest predictor of RV involvement. Thus, these parameters, derived from pulmonary regurgitant tracings, are useful in the noninvasive bedside diagnosis of RV infarction.


Assuntos
Ecocardiografia Doppler , Infarto do Miocárdio/diagnóstico por imagem , Infarto do Miocárdio/fisiopatologia , Insuficiência da Valva Pulmonar/diagnóstico por imagem , Insuficiência da Valva Pulmonar/fisiopatologia , Idoso , Feminino , Ventrículos do Coração , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Valor Preditivo dos Testes , Estudos Prospectivos , Insuficiência da Valva Pulmonar/complicações , Disfunção Ventricular Direita/diagnóstico por imagem , Disfunção Ventricular Direita/fisiopatologia
16.
J Am Soc Echocardiogr ; 10(1): 72-3, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9046496

RESUMO

The impact of aging on the systolic artery pressure (SPAP) value is not well known. We selected 134 echocardiographic Doppler examinations considered as normal (presence of a sinus rhythm, absence of chronic obstructive pulmonary disease or pulmonary embolism, normal global or segmental wall motion, no right or left ventricular hypertrophy or dilatation, no significant valvular disease, no pericarditis), with a clearly measurable tricuspid insufficiency allowing us to measure the SPAP with the simplified Bernoulli equation. There was a highly significant (p = 0.0001) correlation (r = 0.47) between SPAP values and the age of the patient. SPAP increased progressively with age from 23 +/- 5 mm Hg between 20 to 29 years old to 32 +/- 6 mm Hg when 80 years old or more. The interpretation of the SPAP should take into account the age.


Assuntos
Envelhecimento/fisiologia , Pressão Sanguínea , Ecocardiografia Doppler , Artéria Pulmonar/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Artéria Pulmonar/diagnóstico por imagem , Insuficiência da Valva Tricúspide/diagnóstico por imagem , Insuficiência da Valva Tricúspide/fisiopatologia
17.
Biorheology ; 28(3-4): 287-99, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1834246

RESUMO

So far, it has been hypothesized that numerical data obtained in steady flow conditions apply to pulsatile flows. In order to study the modifications of the velocity fields due to pulsatility, jets were produced by 8 orifices (with a diameter "D" of 4.4 to 11.3 mm) included in a chamber of 50 mm. The velocity was measured using laser Doppler anemometry with a pulsatile flow ("pf") and compared to the values obtained in steady ("sf"): at maximum velocity, the longitudinal velocity profile is qualitatively similar to this observed in steady flow: it is made of a plateau followed by an hyperbolic velocity decay in the turbulent area. The length of the core ("Lpf") is strongly related to "D" (Lpf = 3.72 D + 5.49, r = .99) and the velocity decay depends on the ratio between the distance "x" from the orifice and "D" (V/Vo = 2.83D/x + 3.46, r = .85, where V is the velocity at "x" and Vo the initial velocity). During the acceleration and the deceleration, the laminar core is disturbed by turbulences. The comparison of "pf" data with "sf" data demonstrated similar diameters at the origin of the jets (Dpf = 0.96 Dsf + .12, r = .99), but significant (p less than .0001) differences both for "L" and "V/Vo": Lpf = .91Lsf + 6.58, r = .97, V/Vopf = .63 V/Vosf + .34, r = .76. Thus, pulsatility modifies velocity fields and the results obtained in steady flow conditions do not apply to pulsatile jets.


Assuntos
Coração/fisiologia , Modelos Cardiovasculares , Fluxo Pulsátil/fisiologia , Animais , Velocidade do Fluxo Sanguíneo/fisiologia , Lasers , Reologia
18.
Arch Mal Coeur Vaiss ; 96 Spec No 5: 43-50, 2003 Jun.
Artigo em Francês | MEDLINE | ID: mdl-12870191

RESUMO

The evaluation and follow up of insufficiency are matters of "routine" echography. The relevant parameters allow an evaluation of the contractility of the left ventricle (LV), cardiac output, filling pressures, significance of mitral insufficiency (MI), pulmonary pressures, and volumes, and one of the aims is to be able to offer an exhaustive haemodynamic assessment without unnecessarily prolonging the length of the examination. Calculation of the LV ejection fraction is an unavoidable parameter (it is often the inclusion criterion in large studies), recently "rehabilitated" thanks to harmonic imaging. However, the dependence on this index with respect to load conditions, is in fact a very imperfect reflection of LV contractility. The calculation of systolic ejection volume with Doppler (for example from the outflow chamber diameter and sub aortic flow) is a better reflection of LV performance. In the same manner, analysis of the ascending slope of MI flow during isovolumetric contraction (dp/dt) recorded with continuous Doppler allows a reasonably reliable and simple approach to LV contractility, only slightly dependent on load conditions. Numerous parameters allow a reliable evaluation of LV filling pressures: this always relies on the transmitral flow morphology, which has been better interpreted for several years, possibly coupled with a recording of pulmonary venous flow, or even a colour TM mode recording of LV filling or a pulsed tissular Doppler flow recording at the mitral ring. Analysis of the right side of the heart consists of evaluation of the size of the cavities and quantification of the tricuspid flow. Even if the flow is not laminar, it allows a reliable measurement of the pulmonary pressures (by default, pulmonary flow is determined). TM recording in the inferior vena cava has to be systematic to allow evaluation of the right-sided pressures and volumes. Interpretation of these various parameters allows a subtle haemodynamic evaluation in severe cardiac insufficiency, for which the significance is not only diagnostic, but also prognostic: adverse effect of low LVEF; adverse effect of restrictive mitral flow (E/A ratio > 2 and in particular short E deceleration time less than 150 ms), especially if it is not modified by treatment.


Assuntos
Baixo Débito Cardíaco/diagnóstico por imagem , Ecocardiografia Doppler/métodos , Hemodinâmica , Humanos , Disfunção Ventricular Esquerda/diagnóstico por imagem
19.
Arch Mal Coeur Vaiss ; 91(8): 915-9, 1998 Aug.
Artigo em Francês | MEDLINE | ID: mdl-9749137

RESUMO

OBJECTIVE: To determine if the decision to treat uncomplicated mild hypertension with drugs, in accordance with the WHO/ISH guidelines based on a series of blood pressure (BP) measurements over six months, resulted in the treatment of patients at high risk, on the basis of echocardiography. BACKGROUND: The value of echocardiography in mild hypertension management remains is unclear. METHODS: One hundred and eighteen patients with mild hypertension (90 to 105 mmHg diastolic BP and/or 140 to 180 mmHg systolic BP) were examined by echocardiography at inclusion and followed up for 6 months by a single physician unaware of the echographic results. RESULTS: Drug treatment was given to 48 patients, and 70 remained untreated. Treated patients had higher echographic indices than untreated patients (all p < 0.05): LV mass/body surface area (82.8 +/- 15.9 vs 74.7 +/- 15.0 g/m2), interventricular septal thickness (9.7 +/- 1.7 vs 8.5 +/- 1.3 mm). LV posterior wall thickness (8.4 +/- 1.1 vs 7.8 +/- 1.1 mm), relative wall thickness (0.37 +/- 0.06 vs 0.34 +/- 0.06). Left ventricular (LV) geometry was normal in 98 patients, and 20 had LV concentric remodeling. The 10-year coronary disease risk (Framingham equation) was higher in treated patients than in untreated patients (10.0% vs 6.3%; p < 0.002), and in the 20 patients with concentric remodeling than in those with normal LV geometry (10.4%) vs 4.2%; p < 0.005). Nine of these 20 patients were still untreated at the end of the six-month follow-up period. CONCLUSION: Rigorous application of the WHO-ISH clinical guidelines in a group of mild hypertensive patients, led to the treatment of patients with slightly higher LV mass and more concentric LV geometry than were found in those not treated. However, a high-risk subgroup, with concentric remodeling, was not identified and left untreated.


Assuntos
Ecocardiografia , Hipertensão/terapia , Adulto , Feminino , Ventrículos do Coração/diagnóstico por imagem , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Risco , Função Ventricular Esquerda
20.
Arch Mal Coeur Vaiss ; 91(8): 967-70, 1998 Aug.
Artigo em Francês | MEDLINE | ID: mdl-9749146

RESUMO

OBJECTIVE: To assess the ability of 1993 WHO-ISH recommendations to identify patients who need drug treatment. METHODS: 268 hypertensive patients with suspected mild hypertension were preselected for this study at their first visit at the referral center. 123 were included after a short in-hospital work-up when they fulfilled the 1993 WHO-ISH criteria for mild hypertension (90-105 mmHg diastolic BP and/or 140-180 mmHg systolic BP). Echocardiography was performed in all patients by the same investigator according to ASE convention. The combined 10-year risk of stroke and coronary heart disease was calculated with the Framingham equation. Patients were then followed up for six months by the same physician blinded to echographic results and risk calculations and applying the WHO-ISH guidelines (monthly BP measurement and subjective assessment of risk). Five patients were excluded, for reasons unrelated to the protocol. RESULTS: The decision of drug treatment was taken at the 1st, 2nd, 3rd, 4th, 5th, 6th monthly visit after work-up in 2, 6, 25, 7, 2 and 6 patients, respectively. Among these 118 patients, 48 patients (29 male, 19 female) were eventually treated and 70 (49 male, 30 female) remained untreated. BP s at preselection and on a day of work-up were similar in both groups. Patients in whom drug treatment was prescribed were older and had higher lef ventricular mass (LVM) than untreated patients, but only 2 of them (all in the treated group) had LVM values above usual thresholds (LVM > 125 g/m2, in men and women). Stroke and coronary risks were both higher in treated than in untreated patients (p < 0.05). The physician using the guidelines decided to treat only 19 of the 38 patients with a 10-year risk < 10% (true positive), whereas she decided to treat with drugs 12 patients among the 44 with a 10-year risk < 5%. CONCLUSION: The difference in LVM between untreated and treated patients support the validity of the WHO-ISH guidelines, but the measurement of LVM did not bring much information for managing the individual patient. Application of these guidelines did not satisfactorily identify high risk patients and could lead to over-treatment of low risk patients.


Assuntos
Hipertensão/prevenção & controle , Guias de Prática Clínica como Assunto , Idoso , Anti-Hipertensivos/uso terapêutico , Doenças Cardiovasculares/epidemiologia , Ecocardiografia , Feminino , Humanos , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Organização Mundial da Saúde
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