Microsurgical arterial anastomosis in young and adult rats: an evolutive and comparative study

Purpose: To evaluate the caliber of an arterial micro-anastomosis in the young growing animal using a continuous suture technique. Additionally, late morphological changes and blood flows distal to the anastomosis were evaluated. Methods: Seventy-four Wistar rats were submitted to laparotomy to access the aorta for blood flow measurement. The aorta was sectioned using microsurgery technique and an end-to-end anastomosis with continuous suture. After a period of six months to one year, the anastomosis was checked. Results: Regarding the size of the aortas, comparing the pre- and postoperative values, there was an increase of 13.33% in adult animals and 25% in young animals, without any difference in the blood flows. Conclusions: The arteries of young rats show signs of growth at the site of the anastomosis performed with continuous suture.

Research Progress on Vector Flow Imaging of Cardiac Ultrasound / 中国医疗器械杂志

Echocardiogram is vital for the diagnosis of cardiac disease. The heart has complex hemodynamics requiring an advanced ultrasound imaging mode. Cardiac ultrasound vector flow imaging is capable of measuring the actual magnitude and direction of the blood flow velocity, obtaining the quantitative parameters of hemodynamics, and then providing more information for clinical research and diagnosis. This study mainly reviewed several different vector flow imaging techniques for cardiac flow and presented the implementation difficulties, and proposed a diverging wave based high frame rate cardiac ultrasound vector flow imaging. The study discussed the limitation of current ultrasound technology used in the cardiac flow measurement, analyzed and demonstrated the specific reasons for these implementation difficulties and the potential future development.

Signal Conversion and Isolation Processing Technology Used in the Cerebrovascular Stroke Detector / 中国医疗器械杂志

By using Doppler sensor and pressure sensor, the cerebrovascular stroke detector can be used to measure the blood flow velocity and blood pressure of the carotid artery. In this study, a variety of signal conversion and isolation processing techniques are proposed for processing and feature extraction of the output signals from the sensors. Finally, effective signal output waveforms that can be used to evaluate the cerebrovascular hemodynamics index (CVHI) are obtained, and the sound signal outputs that can reflect the change characteristics of blood flow velocity and blood pressure signals are generated, which realizes the application functional requirements of the detector.

Effect of lower limb amputation level on aortic hemodynamics: a numerical study / 生物医学工程学杂志

It has been found that the incidence of cardiovascular disease in patients with lower limb amputation is significantly higher than that in normal individuals, but the relationship between lower limb amputation and the episodes of cardiovascular disease has not been studied from the perspective of hemodynamics. In this paper, numerical simulation was used to study the effects of amputation on aortic hemodynamics by changing peripheral impedance and capacitance. The final results showed that after amputation, the aortic blood pressure increased, the time averaged wall shear stress of the infrarenal abdominal aorta decreased and the oscillatory shear index of the left and right sides was asymmetrically distributed, while the time averaged wall shear stress of the iliac artery decreased and the oscillatory shear index increased. The changes above were more significant with the increase of amputation level, which will result in a higher incidence of atherosclerosis and abdominal aortic aneurysm. These findings preliminarily revealed the influence of lower limb amputation on the occurrence of cardiovascular diseases, and provided theoretical guidance for the design of rehabilitation training and the optimization of cardiovascular diseases treatment.

Research on inversion method of intravascular blood flow velocity based on convolutional neural network / 生物医学工程学杂志

Blood velocity inversion based on magnetoelectric effect is helpful for the development of daily monitoring of vascular stenosis, but the accuracy of blood velocity inversion and imaging resolution still need to be improved. Therefore, a convolutional neural network (CNN) based inversion imaging method for intravascular blood flow velocity was proposed in this paper. Firstly, unsupervised learning CNN is constructed to extract weight matrix representation information to preprocess voltage data. Then the preprocessing results are input to supervised learning CNN, and the blood flow velocity value is output by nonlinear mapping. Finally, angiographic images are obtained. In this paper, the validity of the proposed method is verified by constructing data set. The results show that the correlation coefficients of blood velocity inversion in vessel location and stenosis test are 0.884 4 and 0.972 1, respectively. The above research shows that the proposed method can effectively reduce the information loss during the inversion process and improve the inversion accuracy and imaging resolution, which is expected to assist clinical diagnosis.

Quantitative analysis of the effect of contact pressure on the reflection characteristics of radial pressure wave / 生物医学工程学杂志

The radial artery pulse wave contains a wealth of physiological and pathological information about the human body, and non-invasive studies of the radial artery pulse wave can assess arterial vascular elasticity in different age groups.The piezoelectric pulse wave transducers were used to non-invasively acquire radial artery pulse waves at different contact pressures in young and middle-aged and elderly populations. The radial artery waveforms were decomposed using a triangular blood flow model fitting method to obtain forward and reflected waves and calculate reflection parameters. Finally a correlation analysis and regression analysis of the contact pressure Psensor with the reflection parameters was carried out. The results showed that the reflection parameters RM, RI and Rd had a strong negative correlation with Psensor in both types of subjects, and the correlation coefficients and slopes of the regression curves were significantly different between the two types of subjects (P<0.05). Based on the results of this study, excessive contact pressure on the transducer should be avoided when detecting radial artery reflection waves in clinical practice. The results also show that the magnitude of the slope of the regression curve between the reflection parameters and the transducer contact pressure may be a potentially useful indicator for quantifying the elastic properties of the vessel.

Deslocamento linear longitudinal do ventrículo esquerdo comparado ao strain longitudinal global por ressonância magnética cardiovascular / Left ventricular longitudinal linear displacement versus global longitudinal strain on cardiovascular magnetic resonance

Introdução: A função sistodiastólica do ventrículo esquerdo é prognóstica nas doenças cardiovasculares e pode ser avaliada por strain longitudinal global por meio de ecocardiografia e de ressonância magnética cardíaca. O strain longitudinal global pela ressonância magnética cardíaca exige a utilização de software de alto custo. O deslocamento linear longitudinal do ventrículo esquerdo pode ser uma alternativa simples e barata ao strain longitudinal global, porém eles não foram ainda comparados sistematicamente. Objetivo: Comparar o deslocamento linear longitudinal com o strain longitudinal global e fração de ejeção do ventrículo esquerdo em valvopatas aórticos e controles. Métodos: Incluímos 44 participantes (26 valvopatas aórticos/19 controles). O strain longitudinal global utilizou software específico (Circle Cardiovascular Imaging 42) e o deslocamento linear longitudinal apenas medidas lineares de distância entre a base e o ápex do ventrículo esquerdo, gerando deslocamento máximo, velocidade máxima no início da diástole, velocidade na diástase e a relação entre velocidade na diástase e velocidade máxima no início da diástole. Resultados: Deslocamento máximo e velocidade máxima no início da diástole correlacionaram-se com strain longitudinal global (r=0,69 e r=0,65 respectivamente) e com a fração de ejeção do ventrículo esquerdo (r=0,47 e r=0,57, p<0,001 para ambos). Deslocamento máximo e velocidade máxima no início da diástole apresentaram área sob a curva Característica de Operação do Receptor de 0,88 e 0,91 e, no melhor ponto de corte (-0,13 e 0,66), sensibilidade de 72,43% e 57,14% e especificidade 80,65% e 87,10%, respectivamente, quando comparados ao strain longitudinal global. Utilizando a fração de ejeção do ventrículo esquerdo como referência, foram obtidos 0,70 e 0,82, e, no melhor ponto de corte (-0,11 e 0,61), sensibilidade de 75,00% e 50,00% e especificidade 72,97% e 78,38%, respectivamente. Conclusão: O deslocamento linear longitudinal foi semelhante ao strain longitudinal global. O deslocamento máximo derivado do deslocamento linear longitudinal foi o melhor parâmetro na sístole, enquanto a velocidade máxima no início da diástole foi o melhor na diástole, o que possibilita a avaliação da função diastólica pela ressonância magnética cardíaca na rotina clínica de forma rápida e sem custo adicional.(AU)

Background: Left ventricular (LV) systolic diastolic function is prognostic in cardiovascular diseases and can be assessed via global longitudinal strain (GLS) on echocardiography and cardiac magnetic resonance (CMR). However, GLS by CMR requires the use of expensive software. Longitudinal linear displacement (LLD) may be a simple and inexpensive alternative to GLS, but the two have not been systematically compared. Objective: To compare LLD with GLS and LV ejection fraction (LVEF) in aortic valve disease patients and controls. Methods: We included 44 participants (26 with aortic valve disease, 19 controls). GLS was determined using CVI42 software (Circle Cardiovascular Imaging), while the LLD linear measurements of the distance between the base/apex of the LV included maximum displacement (MD), maximum velocity in early diastole (MVED), atrioventricular junction velocity in diastasis (VDS), and VDS/MVED ratio. Results: DM and MVED were correlated with GLS (r=0.69 and r=0.65, respectively) and LVEF (r=0.47 and r=0.57, p<0.001 for both). DM and MVED showed areas under the receiver operating characteristic curve (AUC) of 0.88 and 0.91, and at the best cut-off point (-0.13 and 0.66), sensitivities of 72.43% and 57.14% and specificities of 80.65% and 87.10%, respectively, compared to GLS. Using LVEF as a reference, we obtained AUC of 0.70 and 0.82, and at the best cut-off point (-0.11 and 0.61), sensitivities of 75.00% and 50.00% and specificities of 72.97% and 78.38%, respectively. Conclusion: LLD demonstrated similar performance to that of GLS. MD derived from LLD was the best parameter during systole, while MVED was the best during diastole. Our findings demonstrate the routine, quick, and inexpensive assessment of diastolic function on CMR.(AU)

Carotid doppler ultrasonography in patients with co-existing type 2 diabetes mellitus and hypertension in Nigeria

Background:The co-existence of diabetes mellitus (DM) and hypertension (HTN) has been rising globally with subclinical atherosclerotic complications. These vascular changes can be detected using carotid ultrasonography. Objectives: To determine and compare the carotid arterial structural wall changes and blood flow velocities of adults with co-existing DM and HTN with age-and sex-matched non-diabetic, non-hypertensive controls. Methods: A cross-sectional comparative study of 300 participants comprising 200 adults with co-existing DM and HTN and 100 age-and sex-matched controls was done. Their carotid arteries were examined bilaterally for plaques, carotid intima media thickness (CIMT) and flow velocities ­peak systolic velocity (PSV), end diastolic velocity (EDV), pulsatility index (PI) and resistive index (RI) using 4­12MHz linear array transducer. Visceral obesity and serum lipids were also assessed. Results: The mean age of the subjects was 56.13 ± 6.93 years; they comprised 38% males and 62% females. The subjects' CIMT was statistically significantly higher (p = 0.001) with a three-fold mean increase (45.5%) compared to the controls (13.7%). Lower flow velocities but higher indices were also observed in the subjects. Strong and significant correlations were observed between EDV and PI r =-0.663, p=>0.001), EDV and RI (r = -0.661, p=>0.001) and PI and RI (r =0.988, p= >0.001)among the subjects. Conclusion: Significant reduction in flow velocities with increased CIMT may be an early indication of subclinical atherosclerosis. Therefore, carotid ultrasonography should be mandatory in individuals at risk for early detection and possible prevention of atherosclerotic complications.

Doppler de arteria umbilical en fetos con síndrome de Down / Umbilical artery Doppler in fetuses with Down syndrome

INTRODUCCIÓN: La aneuploidía más común entre los recién nacidos vivos es el síndrome de Down (SD). En estos niños el crecimiento está disminuido, con una frecuencia del 25% de restricción del crecimiento intrauterino, pero no se ha establecido el papel de la insuficiencia placentaria. El objetivo es estudiar la resistencia placentaria a través del Doppler de arteria umbilical con índice de pulsatilidad (IP) y el tiempo medio de desaceleración (t/2), y el posible efecto de la insuficiencia placentaria en fetos con SD. MÉTODO: Se realizó Doppler en la arteria umbilical en 78 fetos con SD, se midieron el IP y el t/2, y se compararon los resultados con los pesos de nacimiento. RESULTADOS: Se estudiaron 78 fetos con SD con 214 mediciones Doppler. El t/2 y el IP estaban alterados en el 71,5% y el 65% de las mediciones, respectivamente. La incidencia de t/2 alterado aumenta con la edad gestacional desde un 28,6% a las 15-20 semanas hasta un 89,3% sobre las 36 semanas (p < 0,01); cifras similares se observan para el IP. La clasificación de los pesos fue: 64% adecuados, 12% grandes y 24% pequeños para la edad gestacional. La última medición de t/2 antes del parto era normal en el 17% y estaba alterada en el 83%. En el caso del IP, los valores fueron normales en el 27% y anormales en el 73%. El peso de nacimiento, la edad gestacional y el porcentaje de niños adecuados para la edad gestacional eran significativamente mayores en el grupo con Doppler normal que en el grupo con Doppler alterado. El z-score del t/2 estaba marcadamente alterado (−2.23), pero el del peso de nacimiento solo estaba algo disminuido (−0,39). La mortalidad perinatal fue del 10%, significativamente mayor cuando el flujo diastólico era ausente o reverso. CONCLUSIONES: El estudio demuestra que los fetos con SD tienen una alta incidencia de alteración del Doppler umbilical para el IP y el t/2, lo cual sugiere una insuficiencia placentaria grave. Este deterioro parece iniciarse hacia el final del segundo trimestre y aumenta con la edad gestacional. Sin embargo, en estos fetos, la insuficiencia placentaria produce una ligera caída en el crecimiento fetal. Como hipótesis general pensamos que en los fetos con SD hay datos claros de insuficiencia placentaria, pero habría algún factor que les protegería de una restricción grave del crecimiento.

INTRODUCTION: The most common aneuploidy in live newborns is Down syndrome (DS), in these children growth is decreased, with a frequency of 25-36% of fetal growth restriction (FGR); however, it is not established the role of placental insufficiency. The objective is to study the Doppler of the umbilical artery with pulsatility index (PI) and half peak systolic velocity (hPSV) deceleration time and the possible role of placental insufficiency in fetuses with DS. METHOD: Doppler was performed in fetuses with DS, the umbilical artery and IP and hPSV were measured, and the results were compared with birth weights. RESULTS: 78 fetuses with DS were studied with 214 Doppler measurements. hPSV and the IP were altered in 71.5% and 65% of the measurements; the incidence of abnormal hPSV increases with gestational age from 28.6% between 15 to 20 weeks, to 89.3% over 36 weeks (p < 0.01), similar figures are observed with respect to the PI. The weight classification was: 24% of FGR, 12% of great for age and 64% of adequate for gestational age (AGA). The last measurement of hPSV before delivery was normal in 17% of the fetuses and was abnormal in 83%, in the case of PI the normal and abnormal values were 27 and 73%, respectively. Birth weight, gestational age, and the percentage of AGA children were significantly higher in the normal Doppler group than in the abnormal Doppler group. The hPSV z-score was markedly altered (−2.23), but the birth weight z-score is slightly decreased (−0.39). Perinatal mortality is 10% and is significantly higher when diastolic flow is absent or reverse. CONCLUSIONS: The study shows that DS fetuses have a high incidence of abnormal umbilical Doppler measured with IP and hPSV, which suggests severe placental insufficiency, this deterioration seems to start towards the end of the second trimester and increases with gestational age. However, in these fetuses, placental insufficiency causes a discrete drop in fetal growth. As a general hypothesis, we think that there is clear evidence of placental insufficiency in fetuses with DS, but there would be some factor that would protect these fetuses from severe growth restriction.

Meias elásticas de compressão graduada como medida profilática de tromboembolismo venoso e edema de membros inferiores desencadeados por viagens aéreas: uma revisão sistemática de ensaios clínicos / Graduated compression stockings as a prophylactic measure in venous thromboembolism and edema of lower limbs triggered by air travel: a systematic review of clinical trials

Resumo Com o aumento da duração e frequência das viagens aéreas, observou-se um aumento da prevalência de tromboembolismo venoso nos passageiros. Este estudo avaliou a eficácia do uso de meias elásticas de compressão graduada para a prevenção de tromboembolismo venoso desencadeado por viagens aéreas com duração maior que 3 horas de voo. Trata-se de uma revisão sistemática de ensaios clínicos. A qualidade metodológica dos estudos e o nível de evidência científica foram avaliados pelo Consolidated Standards of Reporting Trials e Grading of Recommendations Assessment, Development and Evaluation. Foram identificados 34 artigos, entretanto apenas oito atenderam aos critérios de elegibilidade. Os desfechos incidência de tromboembolismo venoso e edema foram avaliados em 2.022 e 1.311 passageiros, respectivamente. Os estudos demonstraram evidências de alta qualidade para a prevenção de edema e de moderada qualidade para a redução da incidência de tromboembolismo venoso com o uso de meias elásticas de compressão graduada durante viagens aéreas.

Abstract The increase in duration and frequency of flights has led to an increase in the prevalence of venous thromboembolism among airline passengers. This study assesses the efficacy of graduated compression stockings for prevention of venous thromboembolism triggered by flights lasting more than 3 hours. The design is a systematic review of clinical trials. The methodological quality of studies and the level of scientific evidence were evaluated using the Consolidated Standards of Reporting Trials and Grading of Recommendations Assessment, Development and Evaluation standards. A total of 34 articles were identified, but only eight met the eligibility criteria. The outcomes incidence of venous thromboembolism and edema were assessed in 2,022 and 1,311 passengers, respectively. The studies presented high quality evidence demonstrating prevention of edema and moderate quality evidence of reduced incidence of venous thromboembolism associated with wearing graduated compression stockings during flights.

Clinical value of TDI combined with 2D-STI on evaluating the microcirculation dysfunction and left ventricular dysfunction in patients with non-obstructive coronary angina / 中华心血管病杂志

Objective: To explore the value of tissue Doppler imaging (TDI) combined with two-dimensional speckle tracking imaging (2D-STI) at rest on evaluating microcirculation dysfunction and left ventricular dysfunction in patients with angina and no obstructive coronary artery disease(ANOCA). Methods: This retrospective study recruited 78 ANOCA patients, who hospitalized in the People's Hospital of Liaoning Province from August 2019 to July 2021. These patients underwent conventional echocardiography examination, including TDI and 2D-STI, to evaluate the left ventricular dysfunction, and adenosine stress echocardiography (SE) to evaluate the coronary flow velocity reserve (CFVR). ANOCA patients were divided into coronary microcirculation dysfunction CMD group (CFVR<2) and control group (CFVR≥2) according to CFVR. Clinical data, routine echocardiographic parameters, TDI parameters including isovolumic contraction time (IVCT), isovolumic relaxation time (IVRT), ejection time (ET), and STI parameters including global longitudinal peak strain (GLS), time to peak (TTP); peak strain dispersion (PSD) were compared between the two groups. Binary logistic regression was used to analyze the risk factors of CMD and the predictive value of each parameter to construct a joint prediction model for the diagnosis of CMD in this patient cohort. Results: The mean age was (55.5±11.2) years, 43 (55%) patients were females in this patient cohort, 38 (49%) patienst were didvided into the CMD group and 40 (51%) into the control group. Age, prevalence of hypertension, diabetes, dyslipidemia, and smokers were significantly higher in the CMD group than in the control group (all P<0.05). Tei index was higher, IVCT and TTP were longer, PSD was higher, ET was shorter, and absolute GLS was lower in the CMD group than in the control group (all P<0.05). The results of logistic regression analysis showed that longer IVCT, higher Tei index, higher time to PSD and lower absolute GLS were the independent risk factors of CMD. The ROC curve revealed that the predicting efficacy on CMD was satisfactiory with the combined predictors: AUC=0.884, sensitivity of 82% and specificity of 80%. Conclusions: TDI combined with 2D-STI is associated with a good diagnostic value on the diagnosis of CMD and left ventricular dysfunction in patients with ANOCA, which provides a feasible non-invasive tool for the diagnosis of CMD and risk stratification of patients with ANOCA.

The relationship between serum ischemia-modified albumin levels and uterine artery doppler parameters in patients with primary dysmenorrhea

Abstract Objective Primary dysmenorrhea occurs due to abnormal levels of prostanoids, uterine contractions, and uterine blood flow. However, the reasons for pain in primary dysmenorrhea have not yet been clarified. We examined the blood flow alterations in patients with primary dysmenorrhea and determined the relationship between ischemia-modified albumin (IMA) levels, as an ischemia indicator, and primary dysmenorrhea. Methods In the present study, 37 patients who had primary dysmenorrhea and were in their luteal and menstrual phase of their menstrual cycles were included. Thirty individuals who had similar demographic characteristics, who were between 18 and 30 years old and did not have gynecologic disease were included as control individuals. Their uterine artery Doppler indices and serum IMA levels were measured. Results Menstrual phase plasma IMA levels were significantly higher than luteal phase IMA levels, both in the patient and in the control groups (p < 0.001). Although the menstrual phase IMA levels of patients were significantly higher than those of controls, luteal phase IMA levels were not significantly different between the two groups. Menstrual uterine artery pulsatility index (PI) and resistance index (RI) of primary dysmenorrhea patients were significantly different when compared with luteal uterine artery PI and RI levels. There was a positive correlation between menstrual phase IMA and uterine artery PI and RI in the primary dysmenorrhea. Conclusion Ischemia plays an important role in the etiology of the pain, which is frequently observed in patients with primary dysmenorrhea. Ischemia-modified albumin levels are considered as an efficient marker to determine the severity of pain and to indicate ischemia in primary dysmenorrhea.

Medição do Fluxo Sanguíneo Coronário em Angiogramas Coronários Convencionais por um Novo Método Baseado na Detecção da Densidade de Contraste. Uma Visão Fisiológica / Coronary Blood Flow Measurement in Conventional Coronary Angiograms by a New Method Based on Contrast Density Detection. A Physiological Insight

Resumo Fundamento O grau de fluxo TIMI e a contagem quadro a quadro TIMI corrigida (CTFC) são métodos amplamente utilizados para avaliar o fluxo sanguíneo coronariano angiográfico. A medição do fluxo sanguíneo coronariano (FSC) na coronariografia (CAG) padrão despertou grande interesse recentemente, tentando combinar o conceito de CTFC com novos métodos para pós-angioplastia e avaliação da síndrome cardíaca X. Além disso, o fluxo coronariano lento é considerado um critério importante para a angina microvascular. Objetivo Explorar uma nova abordagem de medição angiográfica quantitativa do FSC com base na detecção densitométrica de contraste na CAG offline, usando um software acessível para obter uma avaliação mais precisa e confiável do FSC. Métodos Trinta pacientes foram estudados e divididos em 2 grupos: fluxo sanguíneo coronariano normal (FN) e fluxo sanguíneo coronariano lento (FL), de acordo com a definição da CTFC. O MD foi aplicado à amostra do estudo para diferenciar entre FN e FL. A estatística não paramétrica foi usada para avaliar diferenças entre os grupos com p<0,05. Resultados O valor de referência normal do MD obtido para o fluxo sanguíneo coronariano foi de 9 [5-10] quadros. Os grupos FN vs. FL foi comparado e expresso como mediana [intervalo interquartil], para a artéria descendente anterior esquerda: 10 [7-11] vs. 21 [8-33]; p=0,016; artéria circunflexa: 9 [4-13] vs. 14 [11-30]; p=0,012 e artéria coronária direita: 5 [3-11] vs. 13 [8-26]; p=0,009. Conclusão O MD mostrou a viabilidade de medir o fluxo sanguíneo coronariano com precisão, consistência e reprodutibilidade em um angiograma coronariano padrão, mostrando a capacidade adicional de diferenciar FN de FL em pacientes com dor precordial e artérias coronárias normais. (Arq Bras Cardiol. 2020; 115(3):503-512)

Abstract Background TIMI flow grade and corrected TIMI frame count (CTFC) are widely used methods to evaluate angiographic coronary blood flow. Measurement of coronary blood flow (CBF) on standard coronary angiography (CAG) has aroused great interest recently, trying to combine the CTFC concept with new methods for post-angioplasty and for cardiac syndrome X assessment. Additionally, coronary slow flow it is now considered a major criterion for microvascular angina. Objective Explore a new approach of quantitative angiographic measurement of CBF based on densitometric contrast detection in CAG off-line, using an accessible software to obtain a more precise and reliable CBF assessment. Methods Thirty patients were studied and divided in 2 groups, normal coronary blood flow (NF) and slow coronary blood flow (SF), according to CTFC definition. The DM was applied to the study sample to differentiate between NF and SF. Non-parametric statistics was used to assess differences between groups at p<0.05. Results The DM normal reference value obtained for coronary blood flow was 9 [5-10] frames. NF vs SF group were compared and expressed as median [interquartile range], for the left anterior descending: 10 [7-11] vs 21 [8-33];p= 0.016; circumflex: 9 [4-13] vs 14 [11-30]; p= 0.012 and right coronary artery: 5 [3-11] vs 13 [8-26]; p=0.009. Conclusion The DM showed the feasibility of measuring coronary blood flow with precision, consistency and reproducible in a standard coronary angiogram, showing the additional capability to differentiate between NF and SF in chest pain patients with normal coronary arteries. (Arq Bras Cardiol. 2020; 115(3):503-512)

Ocular blood flow and choroidal thickness changes after carotid artery stenting / Alterações no fluxo sanguíneo ocular e na espessura da coroide após stent de artéria carótida

ABSTRACT Purposes: To evaluate changes in ocular blood flow and subfoveal choroidal thickness in patients with symptomatic carotid artery stenosis after carotid artery stenting. Methods: We included 15 men (mean age, 63.6 ± 9.1 years) with symptomatic carotid artery stenosis and 18 healthy volunteers (all men; mean age, 63.7 ± 5.3 years). All participants underwent detailed ophthalmologic examinations including choroidal thickness measurement using enhanced depth-imaging optic coherence tomography. The patients also underwent posterior ciliary artery blood flow measurements using color Doppler ultrasonography before and after carotid artery stenting. Results: Patients lacked ocular ischemic symptoms. Their peak systolic and end-diastolic velocities increased to 10.1 ± 13.1 (p=0.005) and 3.9 ± 6.3 (p=0.064) cm/s, respectively, after the procedure. Subfoveal choroidal thicknesses were significantly thinner in patients with carotid artery stenosis than those in the healthy controls (p=0.01). But during the first week post-procedure, the subfoveal choroidal thicknesses increased significantly (p=0.04). The peak systolic velocities of the posterior ciliary arteries increased significantly after carotid artery stenting (p=0.005). We found a significant negative correlation between the mean increase in peak systolic velocity values after treatment and the mean preprocedural subfoveal choroidal thickness in the study group (p=0.025, r=-0.617). Conclusions: In patients with carotid artery stenosis, the subfoveal choroid is thinner than that in healthy controls. The subfoveal choroidal thickness increases after carotid artery stenting. Carotid artery stenting treatment increases the blood flow to the posterior ciliary artery, and the preprocedural subfoveal choroidal thickness may be a good predictor of the postprocedural peak systolic velocity of the posterior ciliary artery.

RESUMO Objetivos: Avaliar alterações no fluxo sanguíneo ocular e na espessura da coroide subfoveal em pacientes com estenose sintomática da artéria carótida, após implante de stent nessa artéria. Métodos: Foram incluídos 15 homens (idade média de 63,6 ± 9,1 anos) com estenose sintomática da artéria carótida e 18 voluntários saudáveis (todos homens; idade média de 63,7 ± 5,3 anos). Todos os participantes foram submetidos a exames oftalmológicos detalhados, incluindo d medição da espessura da coroide, usando tomografia de coerência óptica com imagem de profundidade aprimorada. Os pacientes também foram submetidos a medidas do fluxo sanguíneo das artérias ciliares posteriores, usando ultrassonografia com Doppler colorido, antes e após o implante do stent na artéria carótida. Resultados: Os pacientes não apresentaram sintomas isquêmicos oculares. O pico de velocidade sistólica e diastólica final aumentou para 10,1 ± 13,1 (p=0,005) e 3,9 ± 6,3 (p=0,064) cm/s, respectivamente, após o procedimento. As espessuras da coroide subfoveais foram significativamente mais finas nos pacientes com estenose da artéria carótida do que nos controles saudáveis (p=0,01). Porém, durante a primeira semana pós-procedimento, as espessuras das coroides subfoveais aumentaram significativamente (p=0,04). O pico de velocidade sistólica das artérias ciliares posteriores aumentou significativamente após o stent na artéria carótida (p=0,005). Encontramos uma correlação negativa significativa entre o aumento médio dos valores máximos de velocidade sistólica após o tratamento e a espessura da coroide subfoveal pré-procedimento média no grupo de estudo (p=0,025, r=-0,617). Conclusões: Em pacientes com estenose da artéria carótida, a coroide subfoveal é mais fina que a dos controles saudáveis. A espessura da coroide subfoveal aumenta após o stent na artéria carótida. O tratamento com stent na artéria carótida aumenta o fluxo sanguíneo para a artéria ciliar posterior, e a espessura coroidal subfoveal pré-procedimento pode ser um bom preditor da velocidade sistólica de pico pós-procedimento da artéria ciliar posterior.

Aortic isthmus doppler velocimetry in fetuses with intrauterine growth restriction: A literature review / Dopplervelocimetria do istmo aórtico em fetos com crescimento intrauterino restrito: Uma revisão da literatura

Abstract Intrauterine growth restriction (IUGR) is associated with poor perinatal prognosis and a higher risk of stillbirth, neonatal death, and cerebral palsy. Its detection and the evaluation of its severity by new Doppler velocimetric parameters, such as aortic isthmus (AoI), are of great relevance for obstetrical practice. The AoI is a vascular segment that represents a point of communication between the right and left fetal circulations. It is considered to be a functional arterial shunt that reflects the relationship between the systemic and cerebral impedances, and has recently been proposed as a tool to detect the status of hemodynamic balance and prognosis of IUGR in fetuses. In the present review, we noticed that in healthy fetuses, the AoI net flow is always antegrade, but in fetuses with IUGR the deterioration of placental function leads to progressive reduction in its flow until it becomes mostly retrograde; this point is associated with a drastic reduction in oxygen delivery to the brain. The more impaired the AoI flow is, the greater is the risk of impairment in the Doppler velocimetry of other vessels; and the alterations of the AoI Doppler seem to precede other indicators of severe hypoxemia. Although there seems to be an association between the presence of retrograde flow in the AoI and the risk of long-term neurologic disability, its role in the prediction of perinatal morbi-mortality remains unclear. The AoI Doppler seems to be a promising tool in the management of fetuses with IUGR, but more studies are needed to investigate its employment in clinical practice.

Resumo O crescimento intrauterino restrito (CIUR) está associado a um prognóstico perinatal adverso, com maior risco de óbito intrauterino e neonatal, bem como de paralisia cerebral. Assim, sua detecção e a determinação de sua gravidade por novos parâmetros Dopplervelocimétricos, como o istmo aórtico (IAo), são de fundamental importância na prática obstétrica. O IAo é um segmento vascular que representa um ponto de comunicação entre os sistemas circulatórios fetais esquerdo e direito. É considerado um shunt arterial funcional, capaz de refletir a relação entre as impedâncias dos circuitos cerebral e sistêmico, e foi proposto como uma ferramenta para detecção do status do equilíbrio hemodinâmico e do prognóstico de fetos com CIUR. Na presente revisão, observou-se que, em fetos saudáveis, o fluxo predominante no IAo é sempre anterógrado; mas em fetos com CIUR a deterioração do estágio de insuficiência placentária acarreta reduções progressivas no fluxo ístmico até este apresentar sentido predominantemente retrógrado e levar a uma drástica redução no aporte de oxigênio ao sistema nervoso central. Quanto mais alterado estiver o fluxo no IAo, maior a chance de haver alteração na Dopplervelocimetria de outros vasos; e as alterações no Doppler do IAo parecem preceder outros indicadores de hipoxemia severa. Embora o fluxo retrógrado no IAo pareça se correlacionar com maior risco de alteração no desenvolvimento neurológico a longo prazo, ainda não está claro o seu papel na predição de morbimortalidade perinatal. O Doppler do IAo parece ser um parâmetro promissor no manejo do CIUR; entretanto, mais estudos são necessários para avaliar seu emprego na prática clínica.

Modelo predictivo de restricción del crecimiento intrauterino usando doppler de arterias uterinas y edad materna / Predictive model of intrauterine growth restriction using uterine artery doppler and maternal age

INTRODUCCIÓN: La restricción del crecimiento intrauterino representa una importante morbimortalidad perinatal y cuya detección es variable según modelos clínicos y características propias en cada población. OBJETIVO: Evaluar si el Doppler de arterias uterinas y la edad materna conforman un modelo clínico con capacidad predictiva de restricción del crecimiento intrauterino en una amplia muestra de población peruana. MATERIALES Y MÉTODOS: Estudio observacional, analítico, de prueba diagnóstica. Participaron 1344 gestantes atendidas en un centro de referencia nacional materno perinatal Nivel III en Perú entre 2010-2018. La muestra fue seleccionada aleatoriamente y dividida en: muestra de entrenamiento y muestra para validación del mejor modelo clínico obtenido. Se usó análisis multivariado, medición de la capacidad diagnóstica y predictiva. RESULTADOS: El modelo clínico formado por el índice de pulsatilidad promedio mayor al percentil 95 de la arteria uterina y la edad materna mayor a 35 años conformo el modelo con el menor indicador de penalidad de Akaike en comparación con los otros modelos clínicos elaborados en el presente estudio, el índice de Youden fue 0.53. El área bajo la curva ROC fue de 0.75. Se obtuvo una sensibilidad de 71.5%, especificidad 72.1%, valor predictivo positivo 65.8%, valor predictivo negativo 91.2%. CONCLUSIONES: El uso del índice de pulsatilidad promedio de la arteria uterina asociado a la edad materna contribuyen a la formación de un modelo para discriminar RCIU; sin embargo, requiere de otros factores que permitan ajustar el modelo para una mayor tasa de detección.

INTRODUCTION: Intrauterine growth restriction represents an important perinatal morbimortality and its detection varies according to clinical models and characteristics of each population. OBJECTIVES: To evaluate if uterine artery Doppler and maternal age conform a clinical model with predictive capacity of intrauterine growth restriction in a wide sample of Peruvian population. MATERIALS AND METHOD: Observational, analytical, diagnostic test study. A total of 1344 pregnant women attended a national maternal perinatal reference center Level III in Peru between 2010-2018. The sample was randomly selected and divided: training sample and validation sample. In the analysis, multivariate analysis and measurement of diagnostic and predictive capabilities were applied. RESULTS: The clinical model formed by the average pulsatility index greater than the 95th percentile of the uterine artery and maternal age greater than 35 years made up the model with the lowest Akaike's penalty indicator compared to the other clinical models developed in the present study, Youden's index was 0.53. The area under the ROC curve 0.75. Sensitivity 71.5%, specificity 72.1%, positive predictive value 65.8%, negative predictive value 91.2%. CONCLUSIONS: The use of the average pulsatility index of the uterine artery associated with maternal age contributes to the formation of a model to discriminate IUGR; however, it requires other factors to adjust the model for a higher detection rate.

Magnetic resonance angiography and transcranial Doppler ultrasound findings in patients with a clinical diagnosis of vertebrobasilar insufficiency

OBJECTIVE: To evaluate the findings of magnetic resonance angiography (MRA) and transcranial Doppler ultrasound (TCD) in patients with a clinical diagnosis of vertebrobasilar insufficiency (VBI). METHOD: From our outpatient neurotology clinic, we selected patients (using the criteria proposed by Grad and Baloh) with a clinical diagnosis of VBI. We excluded patients with any definite cause for vestibular symptoms, a noncontrolled metabolic disease or any contraindication to MRA or TCD. The patients in the study group were sex- and age-matched with subjects who did not have vestibular symptoms (control group). Our final group of patients included 24 patients (study, n=12; control, n=12). RESULTS: The MRA results did not demonstrate significant differences in the findings between our study and control groups. TCD demonstrated that the systolic pulse velocity of the right middle cerebral artery, end diastolic velocity of the basilar artery, pulsatility index (PI) of the left middle cerebral artery, PI of the right middle cerebral artery, and PI of the basilar artery were significantly higher in the study group than in the control group, suggesting abnormalities affecting the microcirculation of patients with a clinical diagnosis of VBI compared with controls. CONCLUSION: MRA failed to reveal abnormalities in patients with a clinical diagnosis of VBI compared with controls. The PI of the basilar artery, measured using TCD, demonstrated high sensitivity (91%) and specificity (91%) for detecting clinically diagnosed VBI.

Development of a New Type of Atherosclerosis Detection Device / 中国医疗器械杂志

This paper describes how to develop a practical new type of atherosclerosis detection device, which can realize real-time measurement and analysis of human atherosclerosis. According to the mechanism of human atherosclerosis, the design objectives of the system are formulated to determine the construction of the platform. The system calculates the pulse wave velocity by measuring the pulse wave of human fingers and toes, adds four blood pressure measurements to the system design, calculates the ankle-brachial index, and comprehensively measures and analyses the degree of human arteriosclerosis.

Progress and Application Status of Arteriosclerosis Detection Methods / 中国医疗器械杂志

The study comprehensively puts forward several detection methods to arteriosclerosis and mainly discusses the method for pulse wave velocity (PWV for short) and ankle brachial index (ABI for short). On the basis of methods mentioned above, a portable system device for arteriosclerosis detection based on non-invasive PWV and limb blood pressure is introduced, and expectations for the subsequent engineering design and development direction are given for reference.