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1.
Artigo em Inglês, Russo | MEDLINE | ID: mdl-39169583

RESUMO

BACKGROUND: Highly traumatic surgical correction of craniosynostosis (CS) is usually followed by severe postoperative period and high risk of complications. Surgical stress response (SSR) is an important and often neglected cause of severe early postoperative period. OBJECTIVE: To compare clinical and laboratory parameters of SSR in children who underwent various surgeries for CS. MATERIAL AND METHODS: The study included 63 patients aged 7.02±4.12 months. All ones underwent surgery for CS between October 2021 and June 2022. We analyzed clinical and laboratory markers of SSR, as well as correlation with severity of surgical stress. RESULTS: No surgical complications were observed. There were postoperative complications in 12 (19.0%) cases including febrile fever in 9 (14.3%) patients, severe pain and edematous syndromes with prolonged hospital-stay in 3 (4.8%) cases. Significant correlations were revealed between severity of surgical stress and certain laboratory markers (CRP, ACTH, T3, insulin, HOMA-IR). The last ones characterized SSR severity. Patients with high scores of stress response demonstrated more severe course of early postoperative period. CONCLUSION: Surgical stress scale makes it possible to predict early postoperative period and optimize patient management. Lower severity of surgical stress response following endoscopic interventions is another reason for the wider use of low-traumatic surgical methods in pediatric neurosurgery.


Assuntos
Craniossinostoses , Complicações Pós-Operatórias , Estresse Fisiológico , Humanos , Craniossinostoses/cirurgia , Craniossinostoses/sangue , Lactente , Masculino , Feminino , Complicações Pós-Operatórias/sangue , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/diagnóstico , Estudos Prospectivos , Estresse Fisiológico/fisiologia , Pré-Escolar , Biomarcadores/sangue
2.
Diabetes Res Clin Pract ; 212: 111718, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38796080

RESUMO

BACKGROUND: We compared performance of high 1-hour PG level, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) in predicting type 2 diabetes in a longitudinal community-based cohort of Hong Kong Chinese. METHODS: Between 2001 and 2003, 472 adults aged 18-55 years without diabetes underwent 75-gram oral glucose tolerance test (OGTT). Between 2012 and 2014, progression to diabetes was ascertained by reviewing medical records or repeating OGTT and HbA1c. We defined high 1-hour PG as PG ≥ 8.6 mmol/L at 1-hour. RESULTS: In this cohort, 23.5% had normal glucose tolerance and high 1-hour PG, 10.0% had isolated IGT, 4.2% had isolated IFG. Over 12-year follow-up, 9.3% developed type 2 diabetes. In logistic regression, high 1-hour PG was associated with progression to type 2 diabetes with adjusted odds ratio (95% CI) of 4.20 (1.60, 12.40), independent of IFG, IGT and other clinical variables. Areas under ROC (95% CI) for type 2 diabetes were similar between 1-hour (0.84 [0.78, 0.89], 2-hour (0.79 [0.72, 0.86]) and fasting PG (0.79 [0.71, 0.86]). CONCLUSION: High 1-hour PG identified young Chinese with 5-fold increased risk of type 2 diabetes independent of other intermediate hyperglycaemia status and clinical factors. 1-hour PG is similar to fasting and 2-hour PG in predicting type 2 diabetes.


Assuntos
Glicemia , Diabetes Mellitus Tipo 2 , Teste de Tolerância a Glucose , Humanos , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/diagnóstico , Hong Kong/epidemiologia , Masculino , Adulto , Feminino , Pessoa de Meia-Idade , Glicemia/análise , Glicemia/metabolismo , Intolerância à Glucose/sangue , Intolerância à Glucose/epidemiologia , Intolerância à Glucose/diagnóstico , Adulto Jovem , Adolescente , Jejum/sangue , Povo Asiático/estatística & dados numéricos , Progressão da Doença , População do Leste Asiático
3.
Circulation ; 103(22): 2724-30, 2001 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-11390344

RESUMO

BACKGROUND: Controversy continues as to whether adenosine or dobutamine is the superior pharmacological stress agent for myocardial contrast echocardiography (MCE). METHODS AND RESULTS: We compared real-time MCE refilling curves and wall thickening during adenosine and dobutamine stress in 14 open-chest dogs with left anterior descending and left circumflex coronary artery stenoses that reduced hyperemia by 40% to 60% and 70% to 90% (mild and severe non-flow-limiting stenosis, NFLS) and resting flow by 10% to 30% and 35% to 50% (mild and severe flow-limiting stenosis, FLS). MCE was performed with low-energy imaging during Optison infusion. After high-energy bubble destruction, time-intensity data from risk beds were fitted for an exponential function as y=A(1-e(-)(bt)), from which the rate of intensity increase (b) and maximal plateau intensity (A) were derived. Although severe NFLS and greater stenoses decreased b with both dobutamine and adenosine, with mild NFLS it was reduced in 58% of animals with dobutamine versus 8% with adenosine. The absolute decrease in b, however, was greater for adenosine than dobutamine with FLS. The A parameter was decreased with both adenosine and dobutamine only with the most severe FLS. Wall thickening was decreased with dobutamine in 33% of animals with severe NFLS and in all animals with any FLS; with adenosine, in all with severe FLS. CONCLUSIONS: Both dobutamine and adenosine significantly reduce MCE refilling rates in the setting of severe stenosis and in the absence of contractile abnormalities. Dobutamine decreases refilling rate and wall thickening at a less reduced flow grade than adenosine, but adenosine produces a greater magnitude of change than dobutamine.


Assuntos
Adenosina , Doença das Coronárias/diagnóstico por imagem , Dobutamina , Ecocardiografia , Adenosina/farmacologia , Animais , Circulação Coronária/efeitos dos fármacos , Doença das Coronárias/diagnóstico , Doença das Coronárias/fisiopatologia , Dobutamina/farmacologia , Cães , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/patologia , Ventrículos do Coração/fisiopatologia , Hemodinâmica/efeitos dos fármacos , Reprodutibilidade dos Testes , Estresse Fisiológico/fisiopatologia
4.
J Am Coll Cardiol ; 3(4): 992-8, 1984 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-6546768

RESUMO

Intravenous injection of a variety of fluids has been shown to produce right heart contrast by ultrasound, but the intensity and reproducibility achieved are variable. Thus, a new polysaccharide agent being developed for commercial distribution, SHU-454, was quantitatively compared for intensity and variability with agitated saline solution, indocyanine green, carbon dioxide and hydrogen peroxide. Videodensitometry was used to measure peak and total opacification of the right ventricle after peripheral intravenous contrast administration. One hundred eighty injections were performed in nine closed chest dogs while two-dimensional echograms were recorded. SHU-454 yielded the highest peak (p less than 0.001) and total (p less than 0.005) intensity values when compared with the standard agents. In addition, SHU-454 yielded the lowest coefficient of variation between injections (p less than 0.04) in producing this contrast effect. There were no biologically significant changes in heart rate, blood pressure or arterial blood gases during injection of any of the substances used. A newly developed agent, SHU-454, is superior to standard agents in the ability to reliably produce right heart contrast after venous injection in dogs.


Assuntos
Meios de Contraste , Coração/fisiopatologia , Hemodinâmica/efeitos dos fármacos , Polissacarídeos , Animais , Meios de Contraste/efeitos adversos , Meios de Contraste/farmacologia , Densitometria/métodos , Cães , Ecocardiografia/métodos , Injeções Intravenosas , Polissacarídeos/efeitos adversos , Polissacarídeos/farmacologia
5.
J Am Coll Cardiol ; 5(6): 1369-76, 1985 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3998318

RESUMO

No data exist regarding the ability of magnetic resonance imaging to assess cardiac size and performance in human beings. Therefore, measurements of cardiac dimensions by magnetic resonance imaging were compared with those obtained by two-dimensional echocardiography in 21 normal subjects. Magnetic resonance transverse cardiac sections were obtained during electrocardiographic gating using a spin echo pulse sequence. In normal subjects, magnetic resonance imaging yielded a range of values for cardiac dimensions having a similar standard deviation as that of two-dimensional echocardiography. Diastolic measurements of the aorta, left atrium, left ventricle and septum obtained by magnetic resonance imaging correlated well with those obtained by two-dimensional echocardiography (r = 0.82, 0.78, 0.81 and 0.75, respectively). The correlation coefficient of r = 0.35 observed for the posterior wall thickness was not surprising in view of the narrow range of normal values. Only a general correlation (r = 0.53) existed for the right ventricular diastolic dimension; this was probably related to the difficulty in obtaining representative measurements due to the complex geometry of this chamber. Failure of systolic dimension measurements by magnetic resonance imaging to correlate with those obtained by echocardiography is probably related to limitations of electrocardiographic gating, especially of determining the exact end-systolic frame. Although technically complex at present, magnetic resonance imaging does provide an additional noninvasive technique for measurement of cardiac size.


Assuntos
Ecocardiografia , Coração/anatomia & histologia , Espectroscopia de Ressonância Magnética , Adulto , Aorta/anatomia & histologia , Aorta/fisiologia , Função Atrial , Diástole , Eletrocardiografia , Feminino , Coração/fisiologia , Átrios do Coração/anatomia & histologia , Septos Cardíacos/anatomia & histologia , Septos Cardíacos/fisiologia , Ventrículos do Coração/anatomia & histologia , Humanos , Masculino , Pessoa de Meia-Idade , Sístole , Função Ventricular
6.
J Am Coll Cardiol ; 3(4): 999-1004, 1984 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-6368645

RESUMO

In previous studies, indicator-dilution curves obtained by videodensitometry of contrast two-dimensional echocardiograms have shown close correlation with measurements of blood flow in vitro. In this study the technique was extended and contrast indicator-dilution curves obtained in vivo were correlated with simultaneous cardiac output measurements determined by thermodilution in eight dogs. Two-dimensional echocardiograms of the left ventricle were performed with the transducer on the myocardium during left atrial-pulmonary vein injection of 10 cc of a 1 X 10(-4) concentration of 30 mu diameter microballoons. A total of 148 injections were performed at 37 levels of cardiac output (1.70 to 7.90 liters/min) induced by alterations of left ventricular preload, isoproterenol and propranolol. Indicator-dilution curves were obtained from recordings of the analog signal of a linear videodensitometer focused on the left ventricle. Linear regression analysis between total area of the indicator-dilution curves and cardiac output yielded correlation coefficients (r) of 0.77 to 0.96 (mean 0.90) for individual dogs, and 0.65 for all cardiac output determinations in all dogs. Analysis of indicator-dilution curve area by the forward triangle-exponential decay method yielded enhanced individual coefficients of 0.90 to 0.97 (mean 0.94) with cardiac output and 0.61 for the group of animals. It is concluded that echographic indicator-dilution curves obtained from uniform size microballoons and videodensitometry may be obtained in vivo and correlate with cardiac output measurements.


Assuntos
Débito Cardíaco , Ecocardiografia/métodos , Coração/fisiopatologia , Animais , Meios de Contraste , Densitometria/métodos , Cães , Técnicas de Diluição do Indicador , Análise de Regressão , Termodiluição , Gravação em Vídeo
7.
J Am Coll Cardiol ; 3(4): 1013-8, 1984 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-6707338

RESUMO

Fifteen patients (median age 8.5 years) with fixed right ventricular outflow tract obstruction were evaluated by two-dimensional echocardiographically directed continuous wave Doppler ultrasound within 24 hours of cardiac catheterization. Pulmonary artery blood velocity measurements were determined from a real time spectral display of pulmonary artery flow profile and converted to pressure drop utilizing a modified Bernoulli equation. Use of both parasternal and subcostal imaging permitted more accurate detection of maximal flow velocity than did use of either approach alone. Gradients estimated from Doppler recordings correlated well with those measured at cardiac catheterization (correlation coefficient = 0.95, standard error of the estimate = 7.9 mm Hg) with a trend to slight underestimation of gradient in more severe obstruction. In three patients with combined valvular and subvalvular stenosis and one patient with right ventricular outlet obstruction due totally to a ventricular septal aneurysm, Doppler estimation of gradient provided an accurate assessment of total right ventricular-pulmonary artery gradient. Thus, continuous wave Doppler ultrasound combined with two-dimensional echocardiography provides a reliable noninvasive method of estimating pressure gradient in patients with right ventricular outflow tract obstruction.


Assuntos
Pressão Sanguínea , Ecocardiografia/métodos , Comunicação Interventricular/fisiopatologia , Estenose da Valva Pulmonar/fisiopatologia , Ultrassonografia , Adolescente , Adulto , Velocidade do Fluxo Sanguíneo , Criança , Pré-Escolar , Humanos , Lactente , Circulação Pulmonar
8.
J Am Coll Cardiol ; 13(7): 1622-8, 1989 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2723275

RESUMO

Opacification of the left heart chambers after venous injection of echo contrast agents with transpulmonary capabilities has been difficult to achieve because of a lack of availability of a biodegradable nontoxic agent that produces uniformly small microbubbles. SHU-508 is a new saccharide echo contrast agent that produces bubble sizes from 2 to 8 microns in diameter, capable of traversing the pulmonary capillary bed and resulting in left heart contrast. The echo intensity produced by this agent was compared with that of agitated saline solution, indocyanine green and SHU-454 (another experimental saccharide agent for right-sided contrast) during 136 injections in eight dogs. Videotaped two-dimensional echographic images were digitized and analyzed with the use of videodensitometry for peak right and left ventricular intensity, pulmonary transit times and time of persistence of contrast. The highest right ventricular intensity value (3,594 +/- 1,393) was achieved with SHU-508 (p less than 0.05 compared with the other agents). The right ventricular contrast seen with SHU-508 also persisted for a longer period (22.8 +/- 12 s) than with the standard agents (p less than 0.001). Left ventricular contrast with SHU-508 was visually evident in all 42 injections, whereas the peak left ventricular intensity was 35% as bright as that produced in the right ventricle by the same agent. Peak left ventricular intensity values from SHU-508 were compared with those from agitated saline solution injected from the pulmonary capillary wedge position in four dogs. SHU-508 produced brighter left ventricular intensity (1,281 +/- 607) compared with that obtained with the saline-wedge technique (p les than 0.002).(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Meios de Contraste , Ecocardiografia , Polissacarídeos , Animais , Densitometria/métodos , Cães , Verde de Indocianina , Masculino , Cloreto de Sódio
9.
J Am Coll Cardiol ; 2(2): 305-11, 1983 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-6223063

RESUMO

The accuracy of electrocardiography, M-mode echocardiography and two-dimensional echocardiography in predicting left ventricular hypertrophy was compared in 50 patients who came to autopsy within 6 months after the studies were performed. Several methods for determining left ventricular hypertrophy were examined for each of the three techniques. M-mode echocardiography was technically adequate to evaluate the presence or absence of left ventricular hypertrophy more often than either electrocardiography or two-dimensional echocardiography. Measurements from M-mode echocardiography also correlated best with autopsy measurements. Both echocardiographic techniques had a higher sensitivity than electrocardiographic criteria in diagnosing left ventricular hypertrophy. Two-dimensional echocardiography was not shown to improve the M-mode assessment of left ventricular hypertrophy. In an attempt to simplify both M-mode left ventricular mass calculations and the diagnosis of left ventricular hypertrophy for the clinician, a left ventricular mass nomogram was constructed, enabling quick insertion of standard M-mode echocardiographic measurements.


Assuntos
Cardiomegalia/diagnóstico , Ecocardiografia , Eletrocardiografia , Adulto , Idoso , Autopsia , Cardiomegalia/patologia , Ecocardiografia/métodos , Humanos , Pessoa de Meia-Idade , Miocárdio/patologia
10.
J Am Coll Cardiol ; 16(6): 1387-92, 1990 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2229791

RESUMO

The objective of this study was to evaluate the effect of alterations in preload induced by lower body negative pressure on Doppler transmitral filling patterns. Echocardiograms and Doppler recordings were performed in 18 normal young men (aged 23 to 32 years) during various levels of lower body negative pressure (0, -20 and -50 mm Hg). Lower body negative pressure induced a reduction in diastolic velocity integral (from 12.17 +/- 0.79 to 8.42 +/- 0.71 cm, p = 0.0067) and consequently left ventricular diastolic diameter (from 5.11 +/- 0.09 to 4.45 +/- 0.1 cm, p less than 0.0001). There was a significant reflex increase in heart rate from 59.9 +/- 1.9 to 77.1 +/- 2.4 beats/min (p less than 0.0001), but blood pressure was unchanged. This reduction in preload altered Doppler transmittral filling patterns as follows: 1) peak early velocity (E) decreased from 59.2 +/- 3.8 to 39.1 +/- 1.7 cm/s (p less than 0.0001); 2) atrial filing velocity (A) was unchanged (35.58 +/- 1.5 to 33.52 +/- 1.4 cm/s, p = 0.517); 3) E/A ratio decreased from 1.7 +/- 0.13 to 1.19 +/- 0.08 (p = 0.0087); 4) mean acceleration (from 482 +/- 37 to 390 +/- 27 cm/s2, p = 0.03) and mean deceleration (from 327 +/- 31 to 169 +/- 21 cm/s2, p less than 0.001) of the early filling wave were significantly reduced; and 5) peak acceleration (from 907 +/- 42 to 829 +/- 29 cm/s2) and peak deceleration (from 771 +/- 94 to 547 +/- 76 cm/s2) also decreased, but not significantly.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Circulação Coronária/fisiologia , Diástole , Ecocardiografia Doppler , Pressão Negativa da Região Corporal Inferior , Função Ventricular Esquerda/fisiologia , Adulto , Velocidade do Fluxo Sanguíneo , Pressão Sanguínea/fisiologia , Diástole/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Masculino , Valores de Referência
11.
J Am Coll Cardiol ; 6(6): 1306-14, 1985 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3905918

RESUMO

The purpose of this study was to use a canine preparation of experimental aortic stenosis to compare estimates of pressure gradient derived from continuous wave Doppler ultrasound with gradients measured directly by catheterization. Aortic stenosis was created in six mongrel dogs by placing an elastic band around the aorta. Eighty-eight different pressure gradients, ranging from 5 to 160 mm Hg, were produced by variable tightening of the aortic band. Pressure gradients were measured by micromanometer-tipped catheters placed in the left ventricle and aorta. Doppler spectral signals were simultaneously obtained using a 2.0 MHz nonimaging transducer placed directly on the surface of the ascending aorta. Doppler and pressure recordings were analyzed using a custom-designed software program to measure maximal instantaneous, mean and peak to peak gradients, as well as ejection and acceleration times. Maximal instantaneous Doppler gradient showed an excellent linear correlation with maximal instantaneous catheterization gradient (r = 0.98, SEE = 5.3 mm Hg). The correlation of Doppler-estimated maximal gradient to peak to peak catheterization gradient was also linear (r = 0.97, SEE = 6.2 mm Hg) but resulted in a systematic overestimation of pressure drop (mean overestimation = 9.0 mm Hg). Measurement of the Doppler gradient at mid-systole resulted in a more accurate correlation with the peak to peak catheterization gradient (r = 0.98, SEE = 6.1 mm Hg) and eliminated the problem of overestimation.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Estenose da Valva Aórtica/diagnóstico , Ultrassonografia , Animais , Cateterismo Cardíaco , Cães , Modelos Biológicos , Pressão
12.
J Am Coll Cardiol ; 10(1): 125-34, 1987 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-3298357

RESUMO

Time-intensity curves can be obtained from contrast echocardiography of the left ventricle. The purposes of this study were: 1) to verify whether these curves conform to the basic principles of indicator-dilution theory; and 2) to derive indexes of left ventricular ejection fraction from curve analysis. In seven closed chest dogs, 31 doses of the polysaccharide agent SHU-454 were injected into the left ventricular cavity during apical four chamber two-dimensional echocardiography. Data were obtained at different levels of ejection fraction, which were induced by changes in preload, afterload and contractility, and measured by single plane Simpson's rule analysis of digital subtraction left ventriculograms. In a subset of two dogs, eight incremental doses (from 1 to 8 ml) of SHU were injected in the basal state. Contrast echocardiograms were digitized off-line, the mean gray level/pixel of a region of interest inside the left ventricular cavity was measured, and the average value for three systolic frames of each beat was used to obtain time-intensity curves. A good correlation was observed between the peak of the time-intensity curve and the quantity of contrast injected (correlation coefficient r = 0.91 by a logarithmic fit). The echo intensities observed in each animal were subsequently transformed in quantity of contrast according to these functions and their natural logarithm was calculated both with and without background subtraction. All curves relating time and the natural logarithm of the corrected intensity exhibited a descending rectilinear portion (washout) in which the correlation was very good (r = 0.97 +/- 0.02 = mean +/- SD) and which was not significantly affected by background subtraction. The validity of this fit was also unaffected by heart rate (55 to 158 beats/min) and angiographic ejection fraction (22 to 74%), and only minimally influenced by duration of contrast washout (3.3 to 14.6 seconds). Ejection fraction was calculated by an algorithm derived from indicator-dilution theory: ejection fraction = [1 - e(-bd)] X 100, where b = slope of the curve and d = cardiac cycle duration. Linear regression analysis between values of ejection fraction derived by angiography and contrast echo yielded r = 0.73. A second index, based on b and d, was derived by multiple regression analysis. Linear regression analysis of this index and angiographic ejection fraction yielded a correlation of r = 0.87.(ABSTRACT TRUNCATED AT 400 WORDS)


Assuntos
Ecocardiografia , Técnicas de Diluição do Indicador , Volume Sistólico , Animais , Cães , Frequência Cardíaca , Estatística como Assunto , Fatores de Tempo
13.
Am J Cardiol ; 65(1): 78-83, 1990 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-2294685

RESUMO

Isometric exercise produces well-defined hemodynamic changes in normal and diseased states. However, the effect of isometrics on the degree of valvular regurgitation recorded by color Doppler flow imaging (CDFI) has not been reported. CDFI was therefore used to evaluate changes in valvular regurgitation in 34 patients, mean age 53 +/- 16 years. Data were collected for 43 regurgitant lesions including 20 cases of aortic regurgitation and 23 cases of mitral regurgitation. Isometrics produced a significant increase in heart rate (71 to 83 beats/min) and blood pressure (132/64 to 153/70 mm Hg) in all patients (p less than 0.0001). Regurgitant jet area by CDFI increased significantly in both aortic regurgitation (4.5 to 6.2 cm2, p less than 0.0001) and mitral regurgitation (6.2 to 8.2 cm2, p less than 0.001). Patients taking concurrent vasodilator or angiotensin-converting enzyme inhibitor therapy had similar responses to those not receiving long-term therapy. Thus, CDFI detects an increase in aortic and mitral regurgitant jet area induced by isometric exertion. The change in CDFI jet area with handgrip demonstrates the influence of loading conditions on the size of a regurgitant jet area, and suggests that isometric exertion may increase the magnitude of mitral and aortic regurgitation.


Assuntos
Insuficiência da Valva Aórtica/fisiopatologia , Ecocardiografia Doppler , Exercício Físico/fisiologia , Insuficiência da Valva Mitral/fisiopatologia , Insuficiência da Valva Aórtica/diagnóstico , Pressão Sanguínea/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência da Valva Mitral/diagnóstico
14.
Am J Cardiol ; 84(9): 1137-40, A11, 1999 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-10569688

RESUMO

To demonstrate the feasibility and quantify the intensity of right ventricular (RV) myocardial opacification by myocardial contrast echocardiography (MCE), we analyzed MCE produced by intravenous injection of 0.15 ml/kg of QW7437 in 8 closed-chest dogs. MCE could produce visual opacification of the RV wall similar in time course to that of the left ventricular wall, and the data supported the potential role of MCE in evaluating RV hypertrophy, contraction, and perfusion abnormalities.


Assuntos
Meios de Contraste , Ecocardiografia , Fluorocarbonos , Ventrículos do Coração/diagnóstico por imagem , Aumento da Imagem , Animais , Circulação Coronária/fisiologia , Cães , Hipertrofia Ventricular Direita/diagnóstico por imagem , Contração Miocárdica/fisiologia
15.
J Am Soc Echocardiogr ; 5(6): 569-76, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1466881

RESUMO

Standard two-dimensional echocardiographic image planes are defined by anatomic landmarks and assumptions regarding their orientation when these landmarks are visualized. However, variations of anatomy and technique may invalidate these assumptions and thus limit reproducibility and accuracy of cardiac dimensions recorded from these views. To overcome this problem, we have developed a three-dimensional echocardiograph consisting of a real-time scanner, three-dimensional spatial locater, and personal computer. This system displays the line of intersection of a real-time image and an orthogonal reference image and may be used to assess actual image orientation during standardized two-dimensional imaging when the line-of-intersection display is not observed by the operator. Three hundred forty standard images were assessed from 85 examinations by 11 echocardiographers. Twenty-four percent of the unguided standard images were optimally positioned within +/- 5 mm and +/- 15 degrees of the standard. Of the optimal images, two thirds were parasternal long-axis views. A subsequent study with three-dimensional echocardiography and line-of-intersection guidance of image positioning showed 80% of the guided images to be optimally positioned, a threefold improvement (p < 0.001). Two-dimensional echocardiography does not achieve reasonably consistent optimal positioning of standard imaging views, suggesting that measurements taken from these views are likely to be suboptimal. Three-dimensional echocardiography that uses line-of-intersection guidance improves image positioning threefold and should therefore improve the accuracy and reproducibility of quantitative echocardiographic measurements derived from these images.


Assuntos
Ecocardiografia/métodos , Processamento de Imagem Assistida por Computador , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
16.
J Am Soc Echocardiogr ; 14(10): 1010-9, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11593206

RESUMO

Real-time myocardial contrast echo (MCE) provides the potential to assess myocardial blood flow from time-intensity refilling curves after high-energy bubble destruction. This study validated the accuracy of this approach and the effect of specific examination variables and instrument settings on results. The effects of examination depth and angle as well as dynamic range, pulse repetition frequency, and line density were assessed with the use of in vitro incremental flow rates produced in an in vitro tissue phantom. In vivo recordings of real-time imaging with an infusion of a contrast agent (Optison) were obtained in 7 open-chest dogs with graded left anterior descending artery stenosis at baseline and during adenosine hyperemia, and were compared with flow probe measurements. After bubble destruction, time-intensity data were fitted to an exponential function, and the rate of intensity increase (b) and peak plateau intensity (A) were derived from refilling curves. In vivo real-time values for b, but not A, correlated closely with flow probe measures (r = 0.93). A similar correlation for b was observed in vitro (r = 0.98). The correlation between flow rate and b was influenced by several examination variables, including depth, angle, and instrument settings. Real-time MCE provides accurate quantification of coronary flow by assessing the rate of microbubble refilling. However, this parameter may be affected by several examination and instrument variables. Therefore, real-time MCE refilling measures are best applied by comparing baseline values with those of stress studies.


Assuntos
Circulação Coronária , Estenose Coronária/diagnóstico por imagem , Estenose Coronária/fisiopatologia , Ecocardiografia , Animais , Velocidade do Fluxo Sanguíneo , Cães , Ecocardiografia/métodos , Técnicas In Vitro , Análise de Regressão , Reprodutibilidade dos Testes , Fatores de Tempo
17.
Clin Exp Rheumatol ; 17(3): 321-6, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10410265

RESUMO

The Quebec Task Force (QTF) on Whiplash Associated Disorders (WAD)--1995--sent a clear message that we need to re-evaluate the basis for our treatment strategies, and in particular place more emphasis on research to better define these strategies. Judging by many of the clinical strategies currently in use, the Task Force recommendations seem to have been largely ignored three years later. A further compelling reason to re-evaluate our current practices at this time is the finding of much more rapid recovery rates in some cultures, even with little or no therapy. This commentary is a frank consideration of the therapeutic community's responsibility to not only help solve the dilemma of whiplash, but also avoid contributing to the problem. We thus explore a new biopsychosocial model of whiplash, considering the effects of symptom expectation, amplification, and attribution in chronic pain reporting. Based on that model we propose a treatment strategy, and conclude that such strategies provide the only viable approach to this medicolegal and social dilemma.


Assuntos
Traumatismos em Chicotada , Doença Crônica , Humanos , Modelos Biológicos , Cervicalgia , Educação de Pacientes como Assunto , Papel do Doente , Traumatismos em Chicotada/epidemiologia , Traumatismos em Chicotada/psicologia , Traumatismos em Chicotada/terapia
18.
Med Hypotheses ; 56(1): 77-84, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11133259

RESUMO

There are many controversial disability syndromes, representing medicolegal and social dilemmas for a variety of medical disciplines. Health care professionals are at a loss to cure these patients, and judges and disability review boards struggle to be fair while at the same time trying to understand the basis and appropriateness of the ever-growing claims of disability. We review these disability syndromes, examining the basis for their existence, their mechanism, and how these patients can better be understood in a constructive and helpful manner. In doing so, we emphasize the sick role, illness behavior, secondary and tertiary gain, and somatization.


Assuntos
Pessoas com Deficiência , Dor/fisiopatologia , Doença Crônica , Controle de Acesso , Humanos
19.
Med Hypotheses ; 57(4): 459-64, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11601869

RESUMO

Since the introduction of the concept of tertiary gain by Dansak in 1973, there has been little further publication or research on this topic. Yet, tertiary gain is often the subject of debate amongst physicians, therapists, insurers, the media, and even at times the general public. Much of the controversy of disability syndromes and the health and economic burden they present has focused on secondary gain and illness behaviour. The role of tertiary gain in illness behaviour is likely also relevant, and a model of tertiary gain is needed to begin further understanding the implications of this phenomenon for patients and those who treat them. This article introduces a phraseology for tertiary gain, and models the effects of tertiary gain on illness behaviour and the interactions of secondary and tertiary gain in the setting of disability syndromes.


Assuntos
Pessoas com Deficiência/psicologia , Papel do Doente , Humanos
20.
Med Hypotheses ; 57(1): 68-75, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11421629

RESUMO

There are many controversial disability syndromes, representing medicolegal and social dilemmas for a variety of medical disciplines. While illness behavior and sick role phenomena are often invoked to explain many of these syndromes, the extent to which such phenomena are under volitional control has not been thoroughly explored. The volitional control of illness behavior has important treatment implications, and may explain why cognitive therapy can be effective in these patients. Further understanding of the relevance of cognitive theory to illness behavior, the sick role, secondary gain, and disability may render even more effective cognitive therapy approaches. This review explores the consciousness states, the role of each state in information processing (in this case processing illness information), the automaticity and hence volitional state of each level of information processing, and the likelihood that illness behavior in disability syndromes is volitional. The cognitive model of these syndromes considers the interaction of automaticity, volition, and illness behavior and likely has numerous clinical, social, and legal applications.


Assuntos
Cognição , Pessoas com Deficiência/psicologia , Modelos Teóricos , Papel do Doente , Humanos
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