Brachial artery pulsatility index change 1 minute after 5-minute forearm compression - Comparison with flow-mediated dilatation

Objective. Endothelial impairment evaluation by sonographic measurement of flow-mediated dilatation (FMD) has become broadly used. However, this method has 2 main caveats: the dilatation depends on the baseline arterial diameter, and a high precision level is required. Vasodilatation leads to an amplified fall in impedance. We hypothesized that assessment of the pulsatility index change (PI-C) 1 minute after 5-minute forearm compression might evaluate that fall in impedance. The aim of this study was to compare the PI-C with FMD. Methods. Flow-mediated dilatation and the PI-C were assessed in 51 healthy women aged between 35.1 and 67.1 years. We correlated both FMD and the PI-C with age, body mass index, waist circumference, cholesterol level, high-density lipoprotein level, glucose level, systolic and diastolic blood pressure, pulse pressure, brachial artery diameter, simplified Framingham score, intima-media thickness, and carotid stiffness index. Intraclass correlation coefficients between 2 FMD and PI-C measurements were also examined. Results. Only FMD correlated with baseline brachial diameter (r=-0.53). The PI-C had a high correlation with age, body mass index, waist circumference, cholesterol level, systolic blood pressure, pulse pressure, simplified Framingham score, and intima-media thickness. The correlation between FMD and the PI-C was high (r=-0.66). The PI-C had a higher intraclass correlation coefficient (0.991) than FMD (0.836) but not brachial artery diameter (0.989). Conclusions. The PI-C had a large correlation with various markers of cardiovascular risk. Additionally, PI-C measurement does not require offline analysis, extra software, or electrocardiography We think that the PI-C could be considered a marker of endothelial function. However, more studies are required before further conclusions.

Reference ranges for uterine artery pulsatility index during the menstrual cycle: a cross-sectional study

Cyclic endometrial neoangiogenesis contributes to changes in local vascular patterns and is amenable to non-invasive assessment with Doppler sonography. We hypothesize that the uterine artery (UtA) impedance, measured by its pulsatility index (PI), exhibits a regular pattern during the normal menstrual cycle. Therefore, the main study objective was to derive normative new day-cycle-based reference ranges for the UtA-PI during the entire cycle from days 1 to 34 according to the isolated time effect and potential confounders such as age and parity.

PULSATILITY INDEX CHANGE OF BRACHIAL ARTERY SHOWS BETTER REPRODUCIBILITY THAN FLOW-MEDIATED VASODILATION

We aim to evaluate intra- and interobserver reproducibility of brachial artery flow-mediated dilation (FMD) and of pulsatility index change (PI-C) 1 min after a 5-min forearm compression in pregnant women. Flow-mediated dilation and PI-C were assessed in 31 healthy pregnant women in 3 consecutive days, by two observers. A broader range of response to the stimulus was observed for PI-C (-58.99%-86.71%) than FMD (2.38%-27.01%). The intraclass correlation coefficients were higher for PI-C than for FMD (intra = 0.90 vs. 0.69, p = 0.047; inter = 0.94 vs. 0.61, p = 0.007). Therefore, PI-C measurements were more reliable than FMD. However, studies comprising of subjects with cardiovascular risk factors relating FMD and PI-C become necessary to validate this method for the study of endothelial dysfunction. (E-mail: wpmartins@gmail.com) (C) 2010 World Federation for Ultrasound in Medicine & Biology.

Predicting pH at birth in pregnancies with abnormal pulsatility index and positive end-diastolic velocity in the umbilical artery

Objectives: To identify potential associations between fetal surveillance tests and acidosis at birth in pregnancies with abnormal but positive end-diastolic velocity in the umbilical artery. Methods: A prospective case-control study [group 1: pH < 7.2; group 2: pH >= 7.2] including 46 fetuses with abnormal but positive end-diastolic velocity in the umbilical artery was conducted between February 2007 and March 2009. Outcome variables were evaluated by univariate analysis and compared between the two groups. Clinically relevant and statistically significant variables were analyzed by logistic regression. Results: Abnormal nonstress test, presence of deceleration, and absent fetal breathing movements were statistically significant. Logistic regression analysis revealed that fetal heart rate (FHR) deceleration in the nonstress test is the only predictor of fetal acidosis at birth (p = 0.024; OR = 8.2; 95% CI: 1.2-52). Conclusions: In fetuses with positive end-diastolic flow velocity, acute variables of the antenatal surveillance tests are correlated with acidosis at birth and FHR deceleration in the nonstress test is the only predictor of fetal acidosis.

PP080. First trimester umbilical artery end-diastolic flow and pulsatility index: Comparison between preeclampsia and control.

INTRODUCTION The appearance of end-diastolic flow velocities (EDF) in the umbilical artery (UA), usually between 10 and 14 weeks of gestation, has been associated with the opening of the spiral arteries and consequently of the intervillous space. OBJECTIVES The aim of our study was to compare first trimester UA pulsatility index (PI) and EDF between women who developed preeclampsia (cases) and controls. METHODS Our database was searched for cases who had UA Doppler between 10-14 weeks. UA PI and EDF were compared between cases and two gestational age (GA) matched controls. RESULTS 15 cases with severe preeclampsia (PE) were matched to 30 controls. GA with negative EDF was lower than with positive EDF (12.1±0.79 vs. 12.8±0.34; p=0.001). UA PI in cases was higher than in controls, although not significant (cases: 2.18±0.6 vs. CONTROLS 1.92±0.48; p=0.12). However, comparing groups with negative EDF, the difference became significant (PI cases: 2.45±0.57 vs. PI controls: 1.94±0.56; p=0.038), while no difference was found comparing groups with positive EDF. CONCLUSION First trimester UA PI is significantly higher in women which will develop PE than in controls. Interestingly, the timing of screening for PE by UA Doppler seems to play an important issue.

Transcranial Doppler Pulsatility Index: What it is and What it Isn't.

BACKGROUND: Transcranial Doppler (TCD) pulsatility index (PI) has traditionally been interpreted as a descriptor of distal cerebrovascular resistance (CVR). We sought to evaluate the relationship between PI and CVR in situations, where CVR increases (mild hypocapnia) and decreases (plateau waves of intracranial pressure-ICP). METHODS: Recordings from patients with head-injury undergoing monitoring of arterial blood pressure (ABP), ICP, cerebral perfusion pressure (CPP), and TCD assessed cerebral blood flow velocities (FV) were analyzed. The Gosling pulsatility index (PI) was compared between baseline and ICP plateau waves (n = 20 patients) or short term (30-60 min) hypocapnia (n = 31). In addition, a modeling study was conducted with the "spectral" PI (calculated using fundamental harmonic of FV) resulting in a theoretical formula expressing the dependence of PI on balance of cerebrovascular impedances. RESULTS: PI increased significantly (p < 0.001) while CVR decreased (p < 0.001) during plateau waves. During hypocapnia PI and CVR increased (p < 0.001). The modeling formula explained more than 65% of the variability of Gosling PI and 90% of the variability of the "spectral" PI (R = 0.81 and R = 0.95, respectively). CONCLUSION: TCD pulsatility index can be easily and quickly assessed but is usually misinterpreted as a descriptor of CVR. The mathematical model presents a complex relationship between PI and multiple haemodynamic variables.

Prediction of hypertensive disorders in pregnancy by combined uterine artery Doppler, serum biomarkers and maternal characteristics

Objectif: Évaluer l'efficacité du dépistage de l’hypertension gestationnelle par les caractéristiques démographiques maternelles, les biomarqueurs sériques et le Doppler de l'artère utérine au premier et au deuxième trimestre de grossesse. Élaborer des modèles prédictifs de l’hypertension gestationnelle fondées sur ces paramètres. Methods: Il s'agit d'une étude prospective de cohorte incluant 598 femmes nullipares. Le Doppler utérin a été étudié par échographie transabdominale entre 11 +0 à 13 +6 semaines (1er trimestre) et entre 17 +0 à 21 +6 semaines (2e trimestre). Tous les échantillons de sérum pour la mesure de plusieurs biomarqueurs placentaires ont été recueillis au 1er trimestre. Les caractéristiques démographiques maternelles ont été enregistrées en même temps. Des courbes ROC et les valeurs prédictives ont été utilisés pour analyser la puissance prédictive des paramètres ci-dessus. Différentes combinaisons et leurs modèles de régression logistique ont été également analysés. Résultats: Parmi 598 femmes, on a observé 20 pré-éclampsies (3,3%), 7 pré-éclampsies précoces (1,2%), 52 cas d’hypertension gestationnelle (8,7%) , 10 cas d’hypertension gestationnelle avant 37 semaines (1,7%). L’index de pulsatilité des artères utérines au 2e trimestre est le meilleur prédicteur. En analyse de régression logistique multivariée, la meilleure valeur prédictive au 1er et au 2e trimestre a été obtenue pour la prévision de la pré-éclampsie précoce. Le dépistage combiné a montré des résultats nettement meilleurs comparés avec les paramètres maternels ou Doppler seuls. Conclusion: Comme seul marqueur, le Doppler utérin du deuxième trimestre a la meilleure prédictive pour l'hypertension, la naissance prématurée et la restriction de croissance. La combinaison des caractéristiques démographiques maternelles, des biomarqueurs sériques maternels et du Doppler utérin améliore l'efficacité du dépistage, en particulier pour la pré-éclampsie nécessitant un accouchement prématuré.

Effects of estradiol and norethisterone on lipids, insulin resistance and carotid flow

Objectives: To evaluate the lipid profile, insulin resistance and vasomotricity, and the interaction between these factors, in postmenopausal women receiving hormone therapy. Methods: A prospective, randomized, double-blind study was carried out in which 77 postmenopausal women received one of the three treatment regimens: (A) 2 mg oral micronized estradiol (E(2)) (n = 25); (B) 2 mg oral E(2) + 1 mg oral norethisterone acetate (NETA) (n = 28); or Q placebo (n = 24), daily for 6 months. Evaluations were carried out at baseline and at the end of treatment on lipid and lipoprotein profiles, homeostasis model assessment of insulin resistance (HOMA-IR) and pulsatility index (PI) of the internal carotid artery by Doppler ultrasonography. Results: Mean increases of 15.6% and 2.4% and a reduction of 6.4% in high-density lipoprotein (HDL) levels were found for the E(2), E(2) + NETA and placebo groups, respectively. Reductions of 9.5% and 3.7% and an increase of 12.1% in low-density lipoprotein (LDL), and reductions of 20.0% and 3.8% and an increase of 28.8% in the LDL:HDL ratio were found for the E(2), E(2) + NETA and placebo groups, respectively (p < 0.001 in all cases). Insulin levels and HOMA-IR decreased 12.8% and 12.3% in the E2 group and increased 12.9% and 16.0% in the E(2) + NETA group (p < 0.05), respectively. Carotid PI following treatment was 1.18 +/- 0.23, 1.38 +/- 0.20 and 1.41 +/- 0.21 for the E(2), E(2) + NETA and placebo groups, respectively (p = 0.0006). Conclusions: Oral estrogen therapy led to an improvement in lipid profile, insulin resistance and carotid blood flow, which was cancelled when NETA was associated. (c) 2008 Elsevier Ireland Ltd. All rights reserved.

Transferência transplacentária de anticorpos em gestações gemelares

Há poucos dados na literatura sobre o transporte transplacentário de imunoglobulinas em gestações múltiplas. O objetivo deste estudo foi observar fatores que influenciam a concentração de imunoglobulina G (IgG) no cordão umbilical dos neonatos e a transferência transplacentária de IgG total e de IgG contra o Streptococcus grupo B (EGB), e lipopolissacarídeos (LPS) de Klebsiella spp. e Pseudomonas spp.. Métodos: estudo prospectivo realizado no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo no período de 2012 a 2013. Foram coletadas amostras de sangue materno e de cordão umbilical no momento do parto. Os critérios de inclusão foram gestações gemelares com ausência de sinais de infecção por HIV, citomegalovírus, Hepatites B e C, toxoplasmose e rubéola e ausência de doenças autoimunes, malformação fetal e síndromes genéticas. A análise multivariada foi realizada para avaliar a associação entre os níveis de IgG em cordão umbilical e as taxas de transferência de anticorpos com a concentração materna de IgG, a corionicidade da gestação, a presença de insuficiência placentária, a restrição de crescimento intrauterino, a idade gestacional de nascimento, o peso de nascimento, o tabagismo, a doença materna e a via de parto. Resultados: a concentração de IgG total em cordão umbilical apresentou correlação positiva com os níveis maternos séricos de IgG total e a idade gestacional do parto. Os níveis de IgG total em cordão umbilical foram significativamente menores em gestações monocoriônicas quando comparadas às dicoriônicas. A taxa de transferência de IgG total apresentou correlação positiva com a idade gestacional do parto, mas negativa com as concentrações maternas de IgG total. As concentrações de IgG contra EGB e LPS de Klebsiella spp. e Pseudomonas spp. apresentaram associação com os níveis maternos de IgG específicos contra esses antígenos e com o diabetes. Os níveis de IgG contra LPS de Klebsiella spp. também foram associados com o peso de nascimento e com hipertensão materna. As taxas de transferência de IgG contra EGB e LPS de Pseudomonas spp. apresentaram correlação com os níveis maternos de IgG específicos contra os antígenos referidos. A taxa de transferência de IgG contra EGB também esteve associada com a idade gestacional do parto, enquanto a taxa de transferência de IgG contra LPS de Pseudomonas spp. apresentou correlação com diabetes. Não houve correlação entre a taxa de transferência de IgG contra a LPS de Klebsiella spp. com nenhum fator analisado. Conclusão: em gestações gemelares, a concentração total de IgG em cordão umbilical foi influenciada pela concentração materna de IgG total, pela idade gestacional do parto e pela corionicidade placentária. As concentrações de IgG total foram significativamente menores em gestações monocoriônicas que em dicoriônicas. As concentrações séricas de IgG contra EGB e LPS de Klebsiella spp. e Pseudomonas spp. em cordão umbilical apresentaram associação com os níveis maternos de IgG específicos contra esses antígenos e com a presença de diabetes. Todos os outros parâmetros estudados apresentaram diferentes associações com as concentrações de IgG e com as taxas de transferências de IgG específicas contra cada antígeno investigado

Fetal hemodynamic changes following maternal betamethasone administration in pregnancies with fetal growth restriction and absent end-diastolic flow in the umbilical artery

Objectives. To examine the effects of betamethasone administration on umbilical artery (UA), middle cerebral artery (MCA) and ductus venosus (DV) Doppler flow. Design. Longitudinal prospective study. Setting: Fetal Surveillance Unit, Department of Obstetrics and Gynecology, University of Sao Paulo, Sao Paulo, Brazil. Population. Thirty-two singleton pregnancies complicated by fetal growth restriction with absent end-diastolic flow in the UA. Methods. Pulsatility index (PI) of the UA, MCA and DV was measured from 26 to 34 weeks prior to and within 24 or 48 hours after starting betamethasone treatment course. Analysis of variance for repeated measures was used to determine the changes in the fetal hemodynamic Doppler flow following maternal corticosteroid administration. Main outcome measures. Improvement of UA-PI within 24 hours and DV-PIV (venous pulsatility) within 48 hours from the first betamethasone dose. Results. Mean gestational age at delivery was 29.3 (1.8) weeks and birthweight was 806.6 (228.2) g. A reduction in the UA-PI was observed in 29 (90.6%) cases, with return of end-diastolic flow in 22 (68.7%). The mean UA-PI were 2.84 (0.52) before corticosteroid administration, 2.07 (0.56) within 24 hours and 2.42 (0.75) after 48 hours, with a significant difference along the evaluations (p0.001). No significant changes in the MCA Doppler were observed. DV-PIV decreased from 1.06 (0.23) prior corticosteroids administration to 0.73 (0.16) within 24 hours and 0.70 (0.19) after 48 hours (p0.001). Conclusions. There was reduction in the umbilical artery and in the DV pulsatility indices within 24 hours from betamethasone administration that was maintained up to 48 hours.

Disturbed Correlation Between Arterial Resistance and Pulsatility in Glaucoma Patients

PURPOSE: (i) To investigate whether pulsatility index (PI) and mean flow velocities (MFV) are altered in glaucoma patients. (ii) To evaluate the significance of PI in retrobulbar autoregulation capacity. METHODS: Patients with primary open-angle glaucoma (POAG; n = 49), normal tension glaucoma (NTG; n = 62) and healthy controls (n = 48) underwent colour Doppler imaging measurements of the retrobulbar vasculature. Kruskal-Wallis test was used to compare variables between the three diagnostic groups. Restricted cubic splines were used to determine nonlinearities between the resistive index (RI) and PI correlations. RESULTS: Mean flow velocities (MFV) were lower in both short posterior ciliary arteries (SCPA) and central retinal arteries (CRA) from the two glaucoma groups (p < 0.04 versus healthy controls). No differences were detected in RI or PI in any arteries of the three diagnostic groups (p > 0.08). In healthy individuals, correlations between RI and PI were linear in all arteries. In both POAG and NTG patients, CRA presented a nonlinear curve with a cutpoint at RI 0.77 (p < 0.001) and 0.61 (p = 0.03), respectively, above which the slope increased nearly five- and tenfold (POAG: 1.96 to 10.06; NTG: -0.46-4.06), respectively. A nonlinear correlation in the ophthalmic artery was only observed in NTG patients, with a cutpoint at RI 0.82 (p < 0.001), above which the slope increased from 3.47 to 14.03. CONCLUSIONS: Glaucoma patients do not present the linear relationships between RI and PI observed in healthy individuals. Their nonlinear relations may be indicative of an altered autoregulation and suggest a possible threshold RI could be determined above which autoregulatory disturbances become more relevant.

Reference range of uterine artery Doppler parameters between the 11th and 14th pregnancy weeks in a population sample from Northeast Brazil

PURPOSE: To establish reference values for the first trimester uterine artery resistance index (UtA-RI) and pulsatility index (UtA-PI) in healthy singleton pregnant women from Northeast Brazil. METHODS: A prospective observational cohort study including 409 consecutive singleton pregnancies undergoing routine early ultrasound screening at 11 - 14 weeks of gestation was performed. The patients responded to a questionnaire to assess maternal epidemiological characteristics. The left and right UtA-PI and UtA-RI were examined by color and pulsed Doppler by transabdominal technique and the mean UtA-PI, mean UtA-RI and the presence of bilateral protodiastolic notching were recorded. Quartile regression was used to estimate reference values. RESULTS: The mean±standard deviation UtA-RI and UtA-PI were 0.7±0.1 and 1.5±0.5, respectively. When segregated for gestation age, mean UtA-PI was 1.6±0.5 at 11 weeks, 1.5±0.6 at 12 weeks, 1.4±0.4 at 13 weeks and 1.3±0.4 at 14 weeks' gestation and mean UtA-RI was 0.7±0.1 at 11 weeks, 0.7±0.1 at 12 weeks, 0.6±0.1 at 13 weeks and 0.6±0.1 at 14 weeks' gestation. Uterine artery bilateral notch was present in 261 (63.8%) patients. We observed that the 5th and 95th percentiles of the UtA-PI and UtA-RI uterine arteries were 0.7 and 2.3 and, 0.5 and 0.8, respectively. CONCLUSION: Normal reference range of uterine artery Doppler in healthy singleton pregnancies from Northeast Brazil was established. The 95th percentile of UtA-PI and UtA-RI values may serve as a cut-off for future prediction of pregnancy complications studies (i.e., pre-eclampsia) in Northeast Brazil.

Foetal echoencephalography and Doppler ultrasonography of the middle cerebral artery in canine foetuses

Objectives: This study aimed to evaluate the characteristics of the brain and vascular indicesof the middle cerebral artery of canine foetuses. Methods: Twenty-five bitches were selected. Tissue development, echogenicity, echotexture and brain echobiometric data were studied, and the major structures were identified between the 5th and 8th gestational weeks. The area and volume of the brain mass (BMA and BMV), cranial area and volume (AC and VC), brain mass index (BMI) and brain volume index (BVI) were determined. A single ultrasound examination was performed during each studied week (6th, 7th and 8th). Doppler ultrasonography was performed to assess the maximum and minimum velocity, resistance and pulsatility index of middle cerebral artery of the foetuses. Results: Echoencephalography was performed to evaluate the morphological characteristics of the central nervous system. Cerebral echobiometry indicated an increase in area and volume of the hemispheres and cranium (P<0·001) but no changes in BMI or BVI over the gestational period studied. Doppler ultrasonography identified increases in peak systolic velocity (P=0·0188) and end diastolic velocity (P=0·0274) and decreases in resistance index (P=0·0002) and pulsatility index (P<0·001). Clinical Significance: Echoencephalography and spectral Doppler ultrasonography of the middle cerebral artery in canine foetuses might be a useful technique for prenatal care. © 2013 British Small Animal Veterinary Association.

Echobiometrics kidney and renal artery triplex doppler of canine fetuses

O objetivo deste estudo foi avaliar, por meio da ultrassonografia convencional modo B, as características sonográficas e a biometria dos rins de fetos caninos, bem como determinar os índices vasculares da artéria renal dos conceptos ao Doppler Triplex. Foram utilizadas 24 fêmeas Shi-tzu e Pugs pesando de quatro a 10 kg e com idade entre quatro e seis anos. Ao modo B, a ecobiometria renal fetal, a regularidade da superfície renal, a ecotextura e a relação córtico-medular foram avaliadas durante a quinta, sexta, sétima e oitava semanas gestacionais. Ao Doppler Triplex, durante o mesmo período em que se realizou o exame convencional, foram determinados o pico de velocidade sistólica (PVS), a velocidade diastólica final (EDV) e o índice de resistência vascular (RI) e de pulsatividade (PI). Ao modo B, não foram detectadas alterações em rins fetais, e à ecobiometria renal dos fetos, foi possível determinar medidas renais importantes, verificando-se aumento das biometrias no decorrer do desenvolvimento fetal (P<0,0001). Ao Doppler Triplex, determinaram-se os índices vasculares da artéria renal fetal, sendo que os valores para PSV e EDV aumentaram no decorrer das semanas gestacionais (P<0,05) e permaneceram constantes para PI e RI (P>0,05). Concluiu-se que o modo B e o Doppler Triplex são ferramentas importantes para a avaliação do desenvolvimento renal fetal, com a utilização da ecobiometria renal e avaliação dos indices vasculares da artéria renal de fetos caninos.