Comparison of Change in the Pulsatility Index before and after Ventriculoperitoneal Shunt Surgery in Adult Patients with Hydrocephalus.

BACKGROUND AND AIM: In hydrocephalus patients, after ventriculoperitoneal (VP) shunt, decrease in pulsatility index (PI) correlates with decrease in ventricle size. Also, increase in PI is noted in obstructed or malfunctioning VP shunts. However, previous studies were either done in infants and children or included patients of all age groups. Our aim was to compare PI before and after successful VP shunt surgery in adult patients and also the trend of transcranial Doppler (TCD) parameters for 3 days after surgery. MATERIALS AND METHODS: A prospective, observational study was done in 20 adult patients undergoing VP shunt. Clinical features, vitals, Evans index, and TCD parameters were noted in the preoperative period. A computed tomography (CT) head was repeated 4-6 h after surgery, and the position of ventricular end of shunt was confirmed and Evans index was calculated. The vitals and TCD parameters were noted at same time and for the next 2 days. Repeated measures analysis of variance (ANOVA) and paired t-test were uses for statistical analysis. RESULTS: A total of 18 patients were included for statistical analysis. The mean preoperative PI was 1.19 ± 0.24 and the postoperative PI after surgery was 0.97 ± 0.17, 0.97 ± 0.23, and 0.94 ± 0.21 (P = 0.0039) on postoperative day (POD) 1 (POD1), POD2, and POD3, respectively. The mean preoperative value of Evans index was 0.37 ± 0.06 and there was statistically significant (P = < 0.001) reduction to 0.33 ± 0.07 after VP shunt surgery. The change in PI and change in Evans index were found to be positively correlated (r = 0.34 and P = 0.0013). CONCLUSIONS: The decrease in PI after VP shunt surgery correlates with decrease in ventricular size. Any increase in PI in the postoperative period should raise the suspicion of malfunctioning of VP shunt.

Prediction of cerebral infarction after bypass surgery in adult moyamoya disease: using pulsatility index on TCD.

BACKGROUND: At present, the most effective treatment for symptomatic moyamoya disease (MMD) is surgery. However, the high incidence of postoperative complications is a serious problem plaguing the surgical treatment of MMD, especially the acute cerebral infarction. Decreased cerebrovascular reserve is an independent risk factor for ischemic infarction, and the pulsatility index (PI) of transcranial Doppler (TCD) is a common intuitive index for evaluating intracranial vascular compliance. However, the relationship between PI and the occurrence of ischemic stroke after operation is unclear. OBJECTIVE: To explore whether the PI in the middle cerebral artery (MCA) could serve as a potential predictor for the occurrence of ischemic infarction after bypass surgery in MMD. METHODS: We performed a retrospective analysis of data from 71 patients who underwent combined revascularization surgery, including superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis and encephalo-duro-myo-synangiosis (EDMS). The patients were divided into two groups according to the median of ipsilateral MCA-PI before operation, low PI group (MCA-PI < 0.614) and high PI group (MCA-PI ≥ 0.614). Univariate and multivariate regression analysis were used to explore risk factors affecting the occurrence of postoperative cerebral infarction. RESULTS: Among the 71 patients with moyamoya disease, 11 patients had cerebral infarction within one week after revascularization. Among them, 10 patients' ipsilateral MCA-PI were less than 0.614, and another one's MCA- PI is higher than 0.614. Univariate analysis showed that the lower ipsilateral MCA-PI (0.448 ± 0.109 vs. 0.637 ± 0.124; P = 0.001) and higher Suzuki stage (P = 0.025) were linked to postoperative cerebral infarction. Multivariate analysis revealed that lower ipsilateral MCA-PI was an independent risk factor for predicting postoperative cerebral infarction (adjusted OR = 14.063; 95% CI = 6.265 ~ 37.308; P = 0.009). CONCLUSIONS: A lower PI in the ipsilateral MCA may predict the cerebral infarction after combined revascularization surgery with high specificity. And combined revascularization appears to be safer for the moyamoya patients in early stages.

Analysis of the uterine artery pulsatility index on the day of endometrial transformation and pregnancy outcomes of patients undergoing frozen-thawed embryo transfer.

Objective: The objective was to analyze the impact of the uterine artery pulsatility index (PI) on pregnancy outcomes by measuring uterine artery blood flow on the day of endometrial transformation in patients undergoing frozen-thawed embryo transfer (FET). Methods: This was a case-control study. In total, 2,036 patients who underwent FET at the Third Affiliated Hospital of Zhengzhou University from October 2019 to September 2020 were included. The patients were divided into a clinical pregnancy group and a nonclinical pregnancy group according to pregnancy outcome. A multivariate logistic regression model was used to analyze the factors affecting the clinical pregnancy rate. The receiver operating characteristic (ROC) curve was used to determine the optimal mean PI cutoff value of 1.75. After 1:1 propensity score matching (PSM), 562 patients were included. For statistical description and analysis, the patients were divided into two groups: a group with a mean PI > 1.75 and a group with a mean PI ≤ 1.75. Results: The clinical pregnancy group included 1,218 cycles, and the nonclinical pregnancy group included 818 cycles. There were significant differences in female age (P<0.01), infertility type (P=0.04), baseline follicle-stimulating hormone level (P=0.04), anti-Müllerian hormone (AMH) level (P<0.01), antral follicle count (P<0.01), number of transferred embryos (P=0.045) and type of transferred embryo (P<0.01). There was no significant difference in the mean bilateral PI (1.98 ± 0.34 vs. 1.95 ± 0.35, P=0.10). The multivariate analysis results showed that maternal age (AOR=0.95, 95% CI=0.93-0.98, P<0.01), AMH level (AOR=1.00, 95% CI=1.00-1.01, P=0.045), number of transferred embryos (AOR=1.98, 95% CI=1.47-2.70, P<0.01), and type of transferred embryo (AOR=3.10, 95% CI=2.27-4.23, P<0.01) were independent factors influencing the clinical pregnancy rate. The mean PI (AOR=0.85, 95% CI=0.70-1.05; P=0.13) was not an independent factor influencing the clinical pregnancy rate. Participants were divided into two groups according to the mean PI cutoff value of 1.75, and there was no significant difference between the two groups (P > 0.05). Conclusion: In this study, we found that the uterine artery PI on the day of endometrial transformation in patients undergoing FET is not a good predictor of pregnancy outcomes.

Evaluation of choroidal perfusion changes in obese patients: ocular effects of insulin resistance / Avaliação das alterações da perfusão coroidiana em pacientes obesos: efeitos oculares da resistência à insulina

ABSTRACT Purpose: We aimed to evaluate choroidal per­fusion changes in obese patients using optical coherence tomography and dynamic contour tonometry, to determine whether these changes are associated with body mass index, and to assess the ocular effects of insulin resistance. Methods: We retrospectively evaluated the data of 32 obese patients with body mass index >30 kg/m2 and 45 healthy control individuals. Intraocular pressure and ocular pulse amplitude values of the patients were measured using dynamic contour tonometry, and the mean choroidal thickness was measured using enhanced depth imaging optical coherence tomography. Insulin resistance was assessed using the homeostasis model assessment-estimated insulin resistance index. Results: The mean choroidal thickness (294.30 ± 60.87 μm) and ocular pulse amplitude (2.10 ± 0.74) were lower, whereas the mean intraocular pressure (16.61 ± 2.35 mmHg) was higher in obese patients than in controls. There was a significant negative correlation between body mass index and ocular pulse amplitude (r=-0.274; p=0.029) and an insignificant negative correlation between mean choroidal thickness, intraocular pressure, and body mass index. There was an insignificant negative correlation between homeostasis model assessment-estimated insulin resistance index, mean choroidal thickness, and intraocular pressure and significant ne­gative correlation between homeostasis model assessment-estimated insulin resistance index and ocular pulse amplitude (r=-0.317; p=0.022). Conclusion: We found reduced mean choroidal thickness and ocular pulse amplitude and increased mean intraocular pressure in obese patients. These changes indicated a decrease in choroidal perfusion and ocular blood flow. It may be possible to detect ocular blood flow changes in obese patients through noninvasive assessment using the choroid. The negative correlation between insulin resistance and ocular pulse amplitude may be associated with intracellular fat accumulation in obese patients.

RESUMO Objetivo: Avaliar as alterações da perfusão coroidiana em pacientes obesos utilizando tomografia de coerência óptica e a tonometria de contorno dinâmico, para determinar se essas alterações estão associadas ao índice de massa corporal e avaliar os efeitos oculares da resistência à insulina. Métodos: Foram avaliados, retrospectivamente, os dados de 32 pacientes obesos, com índice de massa corporal >30 kg/m2, e 45 controles saudáveis. Os valores de pressão intraocular e da amplitude de pulso ocular dos pacientes foram medidos por meio de tonometria de contorno dinâmico e a espessura média da coroide foi medida por tomografia de coerência óptica com profundidade de imagem aprimorada. A resistência à insulina foi avaliada usando o índice de estimativa da resistência à insulina pelo modelo de homeostase. Resultados: A espessura média da coroideia (294,30 ± 60,87 μm) e a amplitude de pulso ocular (2,10 ± 0,74) foram menores, enquanto a pressão intraocular média (16,61 ± 2,35 mmHg) foi maior nos obesos do que nos controles. Houve uma correlação negativa significativa entre o índice de massa corporal e a amplitude de pulso ocular (r=-0,274; p=0,029) e uma correlação negativa insignificante entre a espessura média da coroide, a pressão intraocular e o índice de massa corporal. Houve uma correlação negativa insignificante entre a avaliação do modelo de homeostase - estimativa do índice de resistência à insulina, espessura média da coróide e pressão intraocular e correlação negativa significativa entre o modelo de avaliação de homeostase - o índice de resistência à insulina estimado e a amplitude de pulso ocular (r=-0,317; p=0,022). Conclusão: Encontramos redução da espessura média da coroide e da amplitude de pulso ocular e aumento da pressão intraocular em pacientes obesos. Essas alterações indicaram uma diminuição na perfusão coroidal e no fluxo sanguíneo ocular. Pode ser possível detectar alterações no fluxo sanguíneo ocular em pacientes obesos por meio de avaliação não invasiva usando a coróide. A correlação negativa entre a resistência à insulina e a amplitude de pulso ocular pode estar associada ao acúmulo de gordura intracelular em pacientes obesos.

Vascular Aging and Arterial Stiffness / Envelhecimento Vascular e Rigidez Arterial

Abstract Cardiovascular diseases (CVD) account annually for almost one third of all deaths worldwide. Among the CVD, systemic arterial hypertension (SAH) is related to more than half of those outcomes. Type 2 diabetes mellitus is an independent risk factor for SAH because it causes functional and structural damage to the arterial wall, leading to stiffness. Several studies have related oxidative stress, production of free radicals, and neuroendocrine and genetic changes to the physiopathogenesis of vascular aging. Indirect ways to analyze that aging process have been widely studied, pulse wave velocity (PWV) being considered gold standard to assess arterial stiffness, because there is large epidemiological evidence of its predictive value for cardiovascular events, and it requires little technical knowledge to be performed. A pulse wave is generated during each cardiac contraction and travels along the arterial bed until finding peripheral resistance or any bifurcation point, determining the appearance of a reflected wave. In young individuals, arteries tend to be more elastic, therefore, the reflected wave occurs later in the cardiac cycle, reaching the heart during diastole. In older individuals, however, the reflected wave occurs earlier, reaching the heart during systole. Because PWV is an important biomarker of vascular damage, highly valuable in determining the patient's global cardiovascular risk, we chose to review the articles on vascular aging in the context of cardiovascular risk factors and the tools available to the early identification of that damage.

Resumo As doenças cardiovasculares são anualmente responsáveis por quase um terço do total de mortes no mundo. Dentre elas, a hipertensão arterial sistêmica (HAS) está relacionada com mais da metade desses desfechos. O diabetes mellitus tipo 2 é visto com um fator de risco independente para HAS por causar lesões funcionais e estruturais na parede arterial, ocasionando-lhe enrijecimento. Diversos estudos relacionam o stress oxidativo, a produção de radicais livres, as alterações neuroendócrinas e genéticas com a fisiopatogenia do envelhecimento vascular. Formas indiretas para analisar esse processo de envelhecimento têm sido amplamente estudadas, dentre elas, a velocidade de onda de pulso (VOP) é vista como o padrão-ouro para avaliar a rigidez arterial por existir maior número de evidências epidemiológicas do seu valor preditivo para eventos cardiovasculares além de requerer pouco conhecimento técnico para sua realização. A onda de pulso é gerada durante cada contração cardíaca e percorre o leito arterial até encontrar resistência periférica ou algum ponto de bifurcação, ocasionando o surgimento de uma onda refletida. Em indivíduos jovens, as artérias tendem a ser mais elásticas, em consequência, a onda é refletida mais tardiamente no ciclo cardíaco e atinge o coração no momento da diástole, enquanto nos mais velhos, com reflexão mais precoce da onda, tende a acontecer na sístole. Por ser a VOP um importante biomarcador de dano vascular, de grande valia para a determinação do risco global cardiovascular do paciente, optamos por revisar os artigos referentes ao envelhecimento vascular no contexto dos fatores de risco cardiovasculares e as ferramentas disponíveis para a identificação precoce desse dano.

O Índice de Perfusão da Oximetria de Pulso na Avaliação da Função Endotelial na Aterosclerose / Evaluation of Endothelial Function on Atherosclerosis using Perfusion Index from Pulse Oximeter

Fundamento: A disfunção endotelial se caracteriza por um fenômeno vascular, com importância evidente em todos os processos da aterogênese. Interessa, assim, a busca por métodos de avaliação da disfunção endotelial mais acurados, práticos e menos dispendiosos, objetivando melhoria na prevenção e tratamento das doenças ateroscleróticas. Objetivo: Verificar o potencial do índice de perfusão derivado da oximetria de pulso (IPP) como método de avaliação da disfunção endotelial em pacientes portadores de aterosclerose Métodos: Foram selecionados 18 pacientes controles e 24 pacientes portadores de doenças ateroscleróticas, em tratamento otimizado, selecionados em Unidades Básicas de Saúde. Foram avaliados os valores do IPP antes a após a aplicação de um estímulo vasodilatador dependente do endotélio - a hiperemia reativa. Também foram analisados os valores do IPP especificamente no período que possui a maior contribuição do óxido nítrico para a vasodilatação (IPP90-120). Os resultados do IPP foram discutidos, por meio da literatura, estimando o seu potencial diagnóstico e prognóstico. Resultados: A resposta vasodilatadora dependente do endotélio mensurada pelo IPP foi significantemente menor em indivíduos com aterosclerose em comparação aos controles a partir de 45 segundos após a hiperemia reativa. Foram observados, do mesmo modo, valores menores do IPP90-120 em pacientes com aterosclerose [35% (4% - 53%) vs. 73% (55% - 169%); p < 0,001]. Tais valores se mantiveram menores tanto em indivíduos masculinos quanto femininos. Conclusões: Os resultados do IPP, demonstrados na avaliação de pacientes ateroscleróticos, associados ao baixo custo da aparelhagem, tornam esse método ...

Background: Endothelial dysfunction is vascular phenomenon that plays an important role in atherosclerosis development. With the purpose of improving the prevention and treatment of atherosclerotic diseases, the searching for accurate, practical and cheaper methods for evaluating endothelial function have become of interest. Objectives: Verify the potential of Peripheral Perfusion Index from pulse oximetry (IPP) as a method of endothelial dysfunction evaluation in patients with atherosclerotic diseases. Methods: There were recruited 18 control patients and 24 patients with atherosclerotic diseases under optimized treatment, in basic health units. The values of IPP were evaluated before and after an endothelial-dependent stimulus, the reactive hyperemia. The values of IPP were also evaluated in period which the major contribution of Nitric Oxide (NO) for the vasodilation occurs (IPP90-120). The results of IPP were discussed using the literature and estimating their diagnostic and prognostic potential Results: The endothelium-dependent vasodilatory response measured by IPP was significantly lower in patients with atherosclerosis compared to control group, since 45 seconds after reactive hyperemia. Also, the values of IPP90-120 were significantly lower in patients with atherosclerosis [35% (4 - 53%) vs 73% (55 - 169%); p<0,001]. Similarly, the IPP values were lower in atherosclerosis group when it was separated by gender. Conclusion: The results of this study, in association with the low cost of pulse oximeter, suggest a good potential for IPP as an endothelial dysfunction evaluation method. New studies must be done in order to clarify this potential and possibly contribute with the prevention and treatment of atherosclerotic diseases. .

Caracterización del flujo pulsante vascular mediante observaciones in vitro en modelos biológico y mecánico / Characterization of the vascular pulsatile flow through in vitro observations on biologic and mechanical models

Objetivo: Tras las evidencias acumuladas con el uso de dispositivos de asistencia circulatoria de flujo pulsante y continuo, surge la polémica sobre los efectos del tipo de flujo en el sistema circulatorio. Este artículo propone la caracterización del flujo pulsante en conductos elásticos, para analizar la influencia de la pulsación en el sistema y entender las peculiaridades del flujo en el lecho vascular. Métodos: Utilizando un dispositivo de bombeo tipo saco elástico de accionamiento neumático, se procedió a la observación visual e instrumental del flujo a través de conductos tanto flexibles (vaso venoso bovino) como rígidos (tubo plástico), y se analizaron las características biomecánicas de la pulsación en ambos. Resultados: Basado en la observación experimental y el análisis biomecánico del flujo pulsante en un conducto elástico, se caracterizó el patrón de la pulsación y se planteó un modelo que explica la influencia de la pulsación en el sistema vascular y los efectos de su ausencia. El modelo propuesto incluye la condición general de flujo (componente mecánico) y su aplicación al sistema vascular (componente fisiológico). Conclusiones: El modelo planteado permite determinar la relación entre las condiciones del flujo y la reacción de la pared, así como unificar la interpretación de factores fluido-dinámicos involucrados a la vez, que advierte sobre los efectos del cambio de flujo y su significado en lo que sería la operación de dispositivos de asistencia circulatoria.

Objective: The evidence accumulated on the use of pulsatile and non-pulsatile flow-dependent devices raises a controversy concerning the effects of the flow type on the Circulatory system. This paper proposes to characterize the properties of pulsatile flow in elastic conduits in order to determine how the pulse affects the system and to determine the specific details of the flow in the vascular bed. Methods: The biomechanical properties of pulsatile flow were measured on flexible (calf venous vessel), and rigid (plastic pipe) conduits in which the flow was implemented using a pneumatic elastic sack-like pumping device. Results: The experimental data and the biomechanical analysis of the pulsing flow was used to determine the flow pattern in order to develop a mechanical model explaining the effects of the pulse on the vascular system. The resulting model includes the flow's general condition (mechanical component) and its effects on the vascular system (biological/physiological component). Conclusions: The model proposed here allows determining the relationship between the flow conditions and the reaction on the wall; it also allows unifying the interpretation of fluid-dynamic factors affecting these phenomena and represents a warning system about the effects of flow changes on the operation of circulatory assistance devices.

Velocidade da onda de pulso em adultos jovens acompanhados por 18 anos: impacto de variáveis pressóricas, antropométricas, metabólicas, inflamatórias e de função endotelial. Estudo do Rio de Janeiro / Pulse wave velocity in young adults followed for 18 years: variable impact of blood pressure, anthropometric, metabolic, inflammatory and endothelial function. Study of Rio de Janeiro

Fundamento: Dados sobre a avaliação não invasiva da rigidez vascular e suas relações com variáveis de risco cardiovascular são escassos em jovens. Objetivo: Avaliar a relação entre a velocidade de onda de pulso (VOP) e a pressão arterial (PA), variáveis antropométricas, metabólicas, inflamatórias e de disfunção endotelial em indivíduos adultos jovens. Método: Foram estudados 96 indivíduos (51 homens) do Estudo do Rio de Janeiro, em duas avaliações, A1 e A2, com intervalo de 17,69+-1,58 anos (16 a 21 anos). Em A1 foram avaliados em suas escolas (10-15 anos - média 12,42+-1,47 anos) e em A2 foram novamente avaliados em nível ambulatorial (26-35 anos - média 30,09+-1,92 anos). Em A1 foram obtidos pressão arterial (PA) e índice de massa corporal (IMC). Em A2 foram obtidos a velocidade da onda de pulso (VOP)-método Complior, PA, IMC, circunferência abdominal (CA), glicose, perfil lipídico, leptina, insulina, adiponectina, o índice de resistência à insulina HOMA-IR, proteína C-Reativa ultrassensivel (PCRus) e as moléculas de adesão E-selectina, Vascular Cell Adhesion Molecule-1(VCAM-1) e Intercellular Achesion Molecule-1 (ICAM-1). Foram obtidos, ainda, a variação da PA e do IMC entre as 2 avaliações. Em A2 os indivíduos foram estratificados segundo o tercil da VOP para cada sexo. Resultados: 1) Os grupos foram constituídos da seguinte forma: Tercil 1:homens com VOP < 8,69 m/s e mulheres com VOP < 7,66 m/s; Tercil 2: homens com VOP >- 8,69 m/s e < 9,65m/s e mulheres com VOP >- 7,66 m/s e < 8,31 m/s; Tercil 3:homens com VOP >- 9,65 m/s e mulheres com VOP >- 8,31 m/s. 2) O grupo com maior tercil de VOP mostrou maiores médias de PA sistólica (PAS) (p=0,005), PA diastólica (PAD) (p=0,007), PA média (PAM) (p=0,004), variação da PAD (p=0,032), variação da PAM (p=0,003), IMC (p=0,046), variação do IMC (p=0,020), insulina (p=0,019), HOMAR-IR (p=0,021), E-selectina (p=0,032) e menores médias de adiponectina (p=0,016), além de maiores prevalências de diabetes ...

Background: Data on non-invasive evaluation of vascular stiffness in the young and its relationship with cardiovascular (CV) risk variables are scarce. Objective: To assess the relationship between pulse wave velocity (PWV) and blood pressure (BP), anthropometric, metabolic, inflammatory and endothelial dysfunction variables in young adults. Methods: Ninety-six individuals (51 males) from The Rio de Janeiro Study cohort were studied in two evaluations, A1 and A2, with and interval of 17.69 +- 1.58 years (16-21 years). In A1 they were evaluated at their schools (10-15 years - aerage 12.42 +- 1.47 years) and in A2 they were all re-evaluated as outpatients (26-35 years - average 30.09 +- 1.92 years). In A1 BP and body mass index (BMI) were obtained. In A2 pulse wave velocity (PWV) by Complior method, BP, BMI, waist circunference (WC), glucose, lipid profile, leptin, insulin, adiponectin, the HOMA-IR insulin resistance index, high sensitive C-Reactive protein (CRPhs) and E-selectin, Vascular Cell Adhesion Molecule 1 (VCAM-1) and Intercellular Adhesion Molecule 1 (ICAM-1) adhesion molecules were obtained. The BP and BMI variation over the time interval between the two evaluations were also obtained. Subjects were stratified according to tertile of PWV for each sex in A2. Results: 1) The groups were constituted as follows: Tertile 1: males with PWV <8.69 m/s and females with PWV <7.66 m/s; Tertile 2: males with PWV >- 8.69 m/s and <9.65 m/s and females with PWV >- 7.66 m/s and <8.31 m/s; Tertile 3: males with PWV >- 9.65 m/s and females with PWV >- 8.31 m/s 2) The group with the highest PWV tertile showed higher values of systolic BP (SBP) (p=0.005), diastolic BP (DBP) (p=0.007), mean BP (MBP) (p=0.004), DBP variation (p=0.032), MBP variation (p=0.033), BMI (p=0.046), BMI variation (p=0.020), insulin (p=0.019), HOMA-IR (p=0.021), E-Selectin (p=0.032) and lower values of adiponectin (p=0.016), besides higher prevalence of diabetes mellitus/glucose intolerance ...

Estimación de la velocidad de propagación aórtica basada en el análisis de la onda de pulso radial / Velocity estimation of aortic propagation based on radial pulse wave analysis

Se exploró la posibilidad de utilizar la morfología del registro de onda de pulso radial obtenida mediante un transductor de movimiento para evaluar la velocidad de propagación aórtica. Se efectuó el registro de onda de pulso en arteria radial mediante un transductor apoyado sobre la zona de palpación del pulso, sobre un conjunto de 167 voluntarios varones sanos normotensos de edades comprendidas entre la 2ª y la 7ª década. Se identificó en los registros la onda reflejada y se definió un coeficiente de velocidad como el cociente entre la talla del individuo y el tiempo transcurrido entre el máximo de la onda sistólica y el instante de llegada de dicha onda. Se halló que en los normotensos el coeficiente mencionado aumentó en forma lineal con la edad, en una proporción similar al aumento de velocidad de propagación aórtica medido con otros métodos. Se repitió el procedimiento en otro conjunto de 125 varones hipertensos sin otros factores de riesgo, de edades entre la 3ª y la 7ª década, hallándose valores similares a los normotensos solamente en la 3ª década, a partir de la cual se registró un incremento significativo de dicho índice. Tales hallazgos sustentan la factibilidad de utilizar tal tipo de registros para evaluar indirectamente la velocidad de propagación junto con el índice de aumentación, un parámetro habitualmente utilizado en el análisis de onda de pulso.

We analyzed the possibility of using the radial pulse wave morphology, obtained by a movement transducer, to evaluate the aortic pulse wave velocity. The radial pulse wave signals were obtained by using a transducer, located on the pulse palpation area, in 167 healthy normotensive male volunteers, ages 20 to 70. The reflected wave was identified in every case. Also, a speed coefficient was defined as the ratio between the individual's height and the time between the maximum systolic wave and the arrival time of the reflected wave. We found that the specified coefficient in normotensive individuals increased linearly with age, in a similar way to the increase in aortic propagation velocity measured by other methods. The procedure was repeated on another set of 125 individuals with hypertension, without other risk factors, aged between the 3rd and 7th decade. This time we found similar values to normotensive individuals only on the 3th decade, and a pronounced increase on the velocity coefficient at advanced ages was observed. These findings support the feasibility of using this type of signals to indirectly evaluate the propagation velocity together with the increase index, a parameter commonly used in pulse wave analysis.

Immediate effects of submaximal effort on pulse wave velocity in patients with Marfan syndrome

Marfan syndrome (MS) is a dominant autosomal disease caused by mutations in chromosome 15, the locus controlling fibrillin 1 synthesis, and may exhibit skeletal, ocular, cardiovascular, and other manifestations. Pulse wave velocity (PWV) is used to measure arterial elasticity and stiffness and is related to the elastic properties of the vascular wall. Since the practice of exercise is limited in MS patients, it was of interest to analyze the acute effect of submaximal exercise on aortic distensibility using PWV and other hemodynamic variables in patients with MS with either mild or no aortic dilatation. PWV and physiological variables were evaluated before and after submaximal exercise in 33 patients with MS and 18 controls. PWV was 8.51 ± 0.58 at rest and 9.10 ± 0.63 m/s at the end of exercise (P = 0.002) in the group with MS and 8.07 ± 0.35 and 8.98 ± 0.56 m/s in the control group, respectively (P = 0.004). Comparative group analysis regarding PWV at rest and at the end of exercise revealed no statistically significant differences. The same was true for the group that used â-blockers and the one that did not. The final heart rate was 10 percent higher in the control group than in the MS group (P = 0.01). Final systolic arterial pressure was higher in the control group (P = 0.02). PWV in MS patients with mild or no aortic dilatation did not differ from the control group after submaximal effort.

Ultrasonografía doppler en embarazos de término con oligohidroamnios aislado / Fetal doppler flow in term pregnancy with isolated oligohydramnios

Objetivos: Evaluar la unidad feto placentaria, mediante ecografía Doppler fetal, en pacientes embarazadas de término con oligohidroamnios aislado (OHA) y comparar los resultados en embarazadas con líquido amniótico normal. Método: Estudio transversal de 19 pacientes con embarazo de término y OHA sin patología asociada. Se compara la evaluación del Doppler con un grupo control de embarazadas con líquido amniótico normal. Como objetivo principal se mide el índice de pulsatilidad (IP) de las arterias renal, cerebral media y umbilical fetal, y como secundarios se evalúan los resultados neonatales. Resultados: Los resultados de la medición Doppler de IP en pacientes con OHA v/s control fueron no significativos: 2,03 v/s 2,04 en arteria renal (p >0,05), 1,37 v/s 1,35 en arteria cerebral media (p >0,05), 0,79 v/s 0,82 en arteria umbilical (p >0,05). Los objetivos secundarios no mostraron diferencias estadísticamente significativas. Conclusión: El OHA aislado en pacientes con embarazo de término no se asocia con alteración del Doppler fetal, por lo que no se relaciona con deterioro de la función placentaria.

Objectives: To evaluate the fetoplacentarian unit through the fetal Doppler flow in term pregnants with oligohidramnios and to compare the fetal outcomes with term pregnants with normal amniotic fuid. Methods: We designed a transversal correlational study of 19 term patients with oligohidramnios and no other pathology. We compare the fetal Doppler values with a control pregnant group with normal amniotic fluid. Our main outcomes were renal, middle cerebral and umbilical artery PI (pulsatility index) and our secondary outcomes were the neonatal results. Results: Patients with oligohidramnios PI Doppler flow values v/s control group were non significant: renal artery 2.03 v/s 2.04 (p >0.05), middle cerebral artery 1.37 v/s 1.35 (p >0.05), umbilical artery 0.79 v/s 0.82 (p>0.05). The secondary outcomes neither were statistically different. Conclusion: There is no association between the isolated oligohidramnios in a term pregnancy and fetal Doppler disorder, for what is not associated with placental dysfunction.

Significado clínico del doppler patológico en la arteria cerebral media en fetos del tercer trimestre / Clinical significance of antenatal pathological doppler findings in the middle cerebral artery in fetuses at third trimester

Antecedentes: La flujometría Doppler fetal es usada de forma rutinaria y sistemática. Es incierta la utilidad clínica del Doppler de la arteria cerebral media (ACM) en fetos del tercer trimestre con crecimiento normal. Objetivo: Determinar los resultados perinatales en fetos del tercer trimestre con índice de pulsatilidad (IP) de la arteria cerebral media (ACM) bajo el percentil 5 comparado con fetos con Doppler cerebral normal. Método: Estudio de cohorte retrospectivo en fetos del tercer trimestre durante 2008. Se seleccionaron dos grupos según IP en la ACM: menor del percentil 5 y mayor del percentil 5. Resultados: Durante el período de estudio 265 fetos cumplieron los criterios de inclusión. Ambos grupos fueron comparables en cuanto a sus características principales. En el grupo con IP menor del percentil 5, la edad gestacional al nacimiento fue mayor: 39,4 vs 38,9 semanas (p=0,001); sin embargo, el número de partos pretérminos fue similar (p=0,89). En el grupo con IP en la ACM menor del 5 se efectuaron 19 (25,7 por ciento) cesáreas por distrés fetal similar al grupo con Doppler cerebral normal 42 (22 por ciento) (p=0,51). No hubo diferencia significativa en ambos grupos respecto al puntaje de Apgar menor de 7 a los 5 minutos (5,4 por ciento vs 3,1 por ciento, p=0,47) ni en el número de ingresos del recién nacido a unidad de cuidados intensivos (10,8 por ciento vs 6,3 por ciento, p=0,32). Conclusiones: Los fetos del tercer trimestre con IP bajo el percentil 5 en el Dopplerde la ACM, muestran resultados perinatales similares a los fetos con Doppler cerebral normal.

Background: Doppler studies are being used routinely and with no specific indication. There is no evidence about the clinical significance of pulsatility index (Pl) below 5th centile in the middle cerebral artery (MCA) in fetuses at third trimester. Objective: To determine perinatal outcomes in fetuses at third trimester with PI<5th centile in the middle cerebral artery (MCA) compared to fetus with normal cerebral Doppler studies. Methods: A retrospective cohort study was designed. We included women pregnant with Doppler studies at third trimester during 2008. We categorized two groups according to the Pl in the MCA, below the 5th centile and above the 5th centile. Results: 265 patients met inclusion criteria. Both groups were similar and homogeneous based on their main characteristics. The Pl below 5th centile group showed a higher mean gestational age 39.4 vs. 38.9 weeks (p=0.001). However, after categorization in preterm delivery below 37 weeks there was no significant difference (p=0.89). In fetuses with PI<5th centile, 19 (25.7 percent) cesarean sections were performed due to fetal distress and similarly 42 (22 percent) cesarean sections were performed in the control group (p=0.51). PI<5th centile was not associated with a 5-min Apgar score below 7 (5.4 percent vs. 3.1 percent, p=0.47). Similarly, there was no difference in the admission to neonatal intensive care unit (10.8 percent vs. 6.3 percent, p=0.31) between both groups. Conclusions: Fetuses at third trimester with pulsatility index below the 5th centile in the cerebral middle artery Doppler have similar perinatal outcomes compared to fetus with normal cerebral Doppler studies.

Análise do perfil hidrodinâmico em diferentes modelos de bombas de rolete utilizadas em circulação extracorpórea / Analysis of the hydrodynamic profile in different roller pumps models used in cardiopulmonary bypass

OBJETIVO: Dentre os equipamentos utilizados em circulação extracorpórea, as bombas de rolete têm grande importância, com diversos modelos disponíveis de vários fabricantes. A calibração é um fator importante nas taxas de hemólise e o seu potencial difere em cada uma delas. Pesquisadores nem sempre abordam detalhes sobre os perfis do leito rígido, supondo que as formas padronizadas de calibração garantem valores iguais e comparáveis para todos os modelos de bombas de rolete. Dispomos principalmente de dois métodos para a calibração das bombas, o que também interfere com o potencial hemolítico. Nenhum dos métodos considera as características de impulsão do fluído, definido pela forma construtiva do leito rígido. O objetivo é avaliar o perfil hidrodinâmico de três modelos de bombas de roletes disponíveis no mercado brasileiro. MÉTODOS: A oclusão dos roletes foi feita por medidas de velocidade de queda e calibração dinâmica. Foram utilizados dois diferentes diâmetros de tubos de silicone (3/8 x 1/16 e 1/2 x 3/32 polegadas). RESULTADOS: Os perfis apresentaram diferenças em suas variâncias. P<0,01 para medidas de velocidade de queda e P<0,0001 para medidas de calibração dinâmica. Foram encontradas diferenças nas variações de pressão entre as bombas analisadas (P<0,002). CONCLUSÃO: As medidas de oclusão são dependentes da forma do leito rígido e comparações envolvendo bombas de rolete devem ser feitas com cautela. Testes com sangue deveriam ser realizados para verificar a influência das variações de pressão na hemólise.

OBJECTIVE: Among the equipments used in cardiopulmonary bypass the roller pumps have great importance with various models available from several manufacturers. The calibration is an important factor in hemolysis rates and its potential is different in each. Researchers do not always approach details on the pump bed profiles assuming that the standardized calibration settings ensure equal and comparable values for all models of roller pumps. We have mainly two methods for calibration of pumps which also interferes on the hemolytic potential. In both of them, the characteristics of fluid impulsion defined by the pump bed design are not considered. The aim of this study is to compare the hydrodynamic profile of three models of roller pumps available in the Brazilian market. METHODS: The rollers occlusion was performed by measures of drop and dynamic calibration. Two different silicone diameter tubes were used (3/8 x 1/16 and 1/2 x 3/32 inches). RESULTS: The profiles showed differences in their variances, P<0.01 for drop rate measures and P<0.0001 for dynamic calibration. Different changes in pressure were found between the pumps analyzed (P<0.002). CONCLUSION: The measures of occlusion are dependent on the design of the pump bed and comparisons involving roller pumps should be performed with caution. Blood tests should be performed to verify the influence of changes in hemolysis pressure.

Doppler das artérias umbilicais e cerebral média fetal após sulfato de magnésio na pré-eclâmpsia / Doppler of the umbilical and fetal middle cerebral arteries after magnesium sulfate in preeclampsia

OBJETIVO: Comparar a relação da artéria umbilical e artéria cerebral média fetal através dos índices dopplervelocimétricos (índice de resistência, índice de pulsatilidade e relação S/D) antes e após a utilização do sulfato de magnésio nas gestantes com pré-eclâmpsia grave (pura ou superposta). MÉTODOS: Foi desenvolvido um estudo do tipo coorte prospectivo, no qual cada sujeito serviu como seu próprio controle. Foram selecionadas 40 gestantes com pré-eclâmpsia grave, submetidas ao exame dopplervelocimétrico antes e após 20 minutos da administração intravenosa de 6 g do sulfato de magnésio. As variáveis estudadas foram os índices dopplervelocimétricos da relação artéria umbilical e cerebral média fetal. A comparação das médias entre as duas medidas (antes e depois) de cada indivíduo foi realizada através do teste t student pareado. A comparação entre a distribuição de freqüência de diagnóstico fetal (normal, redução isolada na resistência da artéria cerebral média e centralizado) foi realizada através do teste Qui quadrado (c²) de Stuart-Maxwell. RESULTADOS: Não foi observada diferença estatisticamente significativa das médias da relação artéria umbilical/cerebral média nos índices dopplervelocimétricos antes e após o sulfato de magnésio. Verificou-se aumento da freqüência de redução isolada na resistência da artéria cerebral média após o sulfato de magnésio (25,0 por cento x 47,5 por cento; p = 0,01). CONCLUSÃO: A administração intravenosa do sulfato de magnésio nas gestantes com pré-eclâmpsia grave resultou em um aumento significativo na freqüência de fetos com diagnóstico de redução da resistência da artéria cerebral média na dopplervelocimetria.

BACKGROUND: To compare the ratio between the fetal middle cerebral artery and the umbilical artery using Doppler flow velocimetry indices (resistance index, pulsatility index and A/B relation) before and after administration of magnesium sulfate to pregnant women with severe preeclampsia (pure or superimposed). METHODS: A prospective cohort study was conducted with each pregnant woman representing her own control. Forty severe preeclamptic women were included and underwent Doppler sonography before and 20 minutes after administration of 6g of magnesium sulfate. Analysis variables were the Doppler flow velocimetry indices evaluating the ratio of the fetal middle cerebral artery to the umbilical artery. To compare the mean indices before and after magnesium sulfate for the same patient, the "t-paired" Student test was used. The Stuart-Maxwell c² was applied to determine the difference of fetal diagnosis (normal, brain-sparing or reduced middle cerebral artery resistance) before and after magnesium sulfate. RESULTS: No significant difference of the mean ratio between the middle cerebral artery and the umbilical artery, before and after administration of magnesium sulfate was observed. After magnesium sulfate (25.0 percent x 47.5 percent; p= 0.01), there was an increased frequency of isolated lower Doppler flow velocimetry indices in the middle cerebral artery. CONCLUSION: Intravenous administration of magnesium sulfate in patients with severe preeclampsia is associated with increased frequency of fetal Doppler diagnosis of reduced resistance in the middle cerebral artery.

Aneurysm pulsatility after endovascular exclusion: an experimental study using human aortic aneurysms

OBJECTIVE: To measure the pulsatility of human aneurysms before and after complete exclusion with an endograft. METHOD: Five aortic aneurysms obtained during necropsy were submitted to pulsatile perfusion before and after implantation of a bifurcated endograft. The specimens were contained in a closed chamber filled with saline solution. A vertical tube attached to the chamber was used to measure volume dislocation in each systole. Mural thrombus was kept intact, and the space around the device was filled with human blood. After each experiment, the aneurysm was opened to check for the correct positioning and attachment of the device. RESULTS: The level of the saline column oscillated during pulsation in each case, with respective amplitudes of 17, 16, 13, 7, and 25 cm before the endograft insertion. After the insertion, the amplitudes dropped to 13, 12, 9, 3.5, and 23 cm, respectively. The differences were not significant. During the post-experimental examination, all devices were found to be in position and well attached to the neck and iliacs. No endoleak was detected during perfusion or by visual inspection. CONCLUSION: Pulsation of an endograft is transmitted to the aneurysm wall even in the absence of endoleak, and should not be interpreted as procedural failure.

Estudio del flujo del líquido cefalorraquídeo (LCR) con cine resonancia magnética (CINE RM) / Cerebrospinal fluid flow Study (LCR) with Cine Magnetic Resonance Imaging (CINE RM)

En el presente trabajo se analiza la experiencia preliminar en la Clínica Las Condes, referida a 69 pacientes. En su indicación predominó la evaluación del tipo de circulación de LCR en quistes aracnoidales, hidrocefalia y malformación de Chiari I con o sin siringomielia. Fue extremadamente útil en los quistes aracnoidales, siendo no comunicantes diez y comunicantes cuatro. En hidrocefalia, ayudó al diagnóstico gracias al flujo hiperdinámico de los ventrículos laterales, producido en esta patología. En la malformación de Chiari I ilustró en forma elegante el efecto pistón, su correción por la descompresiva occipitocervical y la duroplastía de expansión con aponeurosis de pericráneo. Demostró una gran utilidad en el control de funcionalidad de las tercerventrículocisternostomías.

Efeitos da simpaticotomia endoscópica sobre as artérias carótidas e vertebrais na terapêutica cirúrgica da hiperidrose primária / Effects of endoscopic sympathicotomy in carotid and vertebral arteries in the surgical treatment of primary hiperhidrosis

OBJETIVOS: Analisar, em pacientes submetidos a simpaticotomia videotoracoscópica para tratamento da Hiperidrose Primária (HP), as conseqüências hemodinâmicas da desnervação vascular das artérias carótidas e vertebrais após a trans-secção cirúrgica da cadeia simpática torácica (simpaticotomia), através da mensuração de parâmetros ultra-sonográficos. MÉTODO: Vinte e quatro pacientes portadores de HP submetidos a quarenta e oito simpaticotomias torácicas endoscópicas foram avaliados através da mensuração da velocidade de pico sistólico (VPS), velocidade de pico diastólico (VPD), índice de pulsatibilidade (IP) e índice de resistência (IR) nas artérias carótidas comuns, internas e externas, além da artéria vertebral bilateralmente usando o eco-doppler duplex scan. As avaliações foram realizadas antes da intervenção cirúrgica e trinta dias após o procedimento. O teste de Wilcoxon foi usado na análise das diferenças entre as variáveis antes e depois da simpaticotomia. RESULTADOS: A simpaticotomia no nível de T3 foi a trans-secção mais realizada (95,83 por cento), seja isoladamente (25 por cento) ou associada a T4 (62,50 por cento) ou a T2 (8,33 por cento). Houve aumento significativo no IR e no IP da artéria carótida comum bilateralmente (p<0,05). A VPD da artéria carótida interna diminuiu em ambos os lados (p<0,05). A VPS e a VPD da artéria vertebral direita também aumentaram (p<0,05). Achados assimétricos foram observados, de modo que artérias do lado direito foram as mais freqüentemente afetadas. CONCLUSÕES: Alterações hemodinâmicas foram observadas nas artérias vertebral e carótida após simpaticotomia para tratamento de HP. VPS foi o parâmetro mais freqüentemente alterado, principalmente nas artérias do lado direito, representando alterações assimétricas significantes nas artérias carótida e vertebral. Entretanto, são necessárias pesquisas subseqüentes para verificar se essas alterações são definitivas ou temporárias, uma vez que as inferências clínicas somente terão validação se as alterações forem permanentes.

Cambios en la hemodinamia cerebral y sistémica en recién nacidos bajo sedación y analgesia con fentanilo / Changes in cerebral and systemic hemodynamics in newborns under sedation and analgesi with fentanyl

Introducción. Objetivo: determinar las variaciones del flujo sanguíneo cerebral con la aplicación de fentanilo en neonatos críticamente enfermos. Material y métodos. Diseño: estudio longitudinal, prospectivo, descriptivo y observacional. Si Neonatología del Hospital de Pediatría, Centro Médico Nacional. Se incluyeron 18 pacientes tratados con fentanilo en bolo (5 µg / kg) e infusión contimua (3 µg/kg/hora). Se hicieron mediciones basales, a la hora y a las 24 horas de la aplicación del fármaco de la tensión arterial (TA) sistólica, diastólica y media y por ultrasonido (Modo M y B) se midieron las fracciones de eyección y acortamiento del ventrículo izquierdo. Por medio de Doppler pulsado se midieron la velocidad de flujo sanguíneo y el índice de pulsatilidad de la arteria cerebral anterior en los mismos momentos establecidos. Resultados. Se encontraron diferencias significativas en: la TA diastólica, la telediástole de la arteria cerebral y la fracción de acortamiento entre las mediciones basales y a las 24 horas (P< 0.05) para cada una de ellas. No hubo efecto adverso con el tratamiento en ninguna de las mediciones hemodinámicas, sistémicas o cerebrales. Conclusiones. Las diferencias encontradas entre los valores basales y los subsecuentes probablemente se atribuyan a la administración de fentanilo

Amenorrea hipotalámica, concepto, clasificación y alternativas terapeúticas / Hipothalamic amenorrhea, concept, clasification and therapeutical alternatives

El desarrollo de amenorrea hipotalámica refleja generalmente una respuesta individual al stress ambiental y al propio estilo de vida. En la mayoría de los casos, no hay una anormalidad anatómica detestable del eje hipotálamo-hipófisis-ovario-endometrio. Numerosas evidencias sugieren que el defecto de base es una reducción de la actividad del generador hipotalámico de pulsos de GNRH. Los factores neuroendocrinos que regulan la función de este centro son parcialmente conocidos. El sistema opioidérgico y dopaminérgico han sido implicados como posibles factores en la reducción de la secreción pulsátil de GNRH. Debido a la naturaleza por lo general funcional del trastorno, se espera una reactivación de la actividad pulsátil de GNRH una vez superado los factores que lo desencadenaron. La persistencia de la anovulación obliga a una terapia de reemplazo hormonal fundamentalmente por el riesgo de terapia de reemplazo hormonal fundamentalmente por el riesgo de osteoporosis. En las pacientes que desean fertilidad, la inducción de ovulación con GNRH pulsátil es la alternativa terapéutica más efectiva

Secreçäo pulsátil de progesterona em mulheres ovulatórias normais e em mulheres com defeitos da fase lútea / Pulsatile progesterone secretion in normal ovulatory women wiht luteal ohase defects

Neste trabalho avaliamos a secreçao pulsátil de P(4) na fase lútea de mulheres ovulatórias normais e mulheres com LPD. Observamos que nao houve diferença significativa entre os grupos em relaçao aos níveis basais, secreçao média e outros parâmetros da secreçao pulsátil (amplitude absoluta e freqüência), a nao ser a amplitude percentual dos pulsos. Portanto, a dosagem exclusiva de P(4), valores absolutos ou secreçao pulsátil, nao se presta ao diagnóstico de LPD, necessitando de outros métodos omplementares.