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1.
Jakub Kaczynski Rachel Home Karen Shields Matthew Walters William Whiteley Joanna Wardlaw David E. Newby 《Cardiovascular ultrasound》2018,16(1):15
Background
Transcranial Doppler ultrasound remains the only imaging modality that is capable of real-time measurements of blood flow velocity and microembolic signals in the cerebral circulation. We here assessed the repeatability and reproducibility of transcranial Doppler ultrasound in healthy volunteers and patients with symptomatic carotid artery stenosis.Methods
Between March and August 2017, we recruited 20 healthy volunteers and 20 patients with symptomatic carotid artery stenosis. In a quiet temperature-controlled room, two 1-h transcranial Doppler measurements of blood flow velocities and microembolic signals were performed sequentially on the same day (within-day repeatability) and a third 7–14 days later (between-day reproducibility). Levels of agreement were assessed by interclass correlation co-efficient.Results
In healthy volunteers (31±9 years, 11 male), within-day repeatability of Doppler measurements were 0.880 (95% CI 0.726–0.950) for peak velocity, 0.867 (95% CI 0.700–0.945) for mean velocity, and 0.887 (95% CI 0.741–0.953) for end-diastolic velocity. Between-day reproducibility was similar but lower: 0.777 (95% CI 0.526–0.905), 0.795 (95% CI 0.558–0.913), and 0.674 (95% CI 0.349–0.856) respectively. In patients (72±11 years, 11 male), within-day repeatability of Doppler measurements were higher: 0.926 (95% CI 0.826–0.970) for peak velocity, 0.922 (95% CI 0.817–0.968) for mean velocity, and 0.868 (95% CI 0.701–0.945) for end-diastolic velocity. Similarly, between-day reproducibility revealed lower values: 0.800 (95% CI 0.567–0.915), 0.786 (95% CI 0.542–0.909), and 0.778 (95% CI 0.527–0.905) respectively. In both cohorts, the intra-observer Bland Altman analysis demonstrated acceptable mean measurement differences and limits of agreement between series of middle cerebral artery velocity measurements with very few outliers. In patients, the carotid stenoses were 30–40% (n?=?9), 40–50% (n?=?6), 50–70% (n?=?3) and?>?70% (n?=?2).No spontaneous embolisation was detected in either of the groups.Conclusions
Transcranial Doppler generates reproducible data regarding the middle cerebral artery velocities. However, larger studies are needed to validate its clinical applicability.Trial registration
ClinicalTrial.gov (ID NCT 03050567), retrospectively registered on 15/05/2017.2.
Background
Improvements in ultrasound technology has enabled direct, transthoracic visualization of long portions of coronary arteries : the left anterior descending (LAD), circumflex (Cx) and right coronary artery (RCA). Transthoracic measurements of coronary flow velocity were proved to be highly reproducible and correlated with invasive measurements. While clinical applications of transthoracic echocardiography (TTE) of principal coronary arteries are still very limited they will likely grow. The echocardiographers may therefore be interested to know the ultrasonic views, technique of examination and be aware where to look for coronary arteries and how to optimize the images.Methods
A step-by-step approach to direct, transthoracic visualization of the LAD, Cx and RCA is presented. The technique of examination is discussed, correlations with basic coronary angiography views and heart anatomy are shown and extensively illustrated with photographs and movie-pictures. Hints concerning optimization of ultrasound images are presented and artifacts of imaging are discussed.Conclusions
Direct, transthoracic examination of the LAD, Cx and RCA in adults is possible and may become a useful adjunct to other methods of coronary artery examination but studies are needed to establish its role. 相似文献3.
Stavros K Kakkos Andrew N Nicolaides Efthyvoulos Kyriacou Constantinos S Pattichis George Geroulakos 《Cardiovascular ultrasound》2006,4(1):1-10
Background
The effect of age on common carotid artery diameter is unclear for varying atherosclerosis risk levels.Methods
Cross-sectional data from the Atherosclerosis Risk in Communities Limited Access Data set were used to estimate the association of age with B-mode ultrasound common carotid artery diameter for three atherosclerosis risk levels. Based on information from clinical examinations, B-mode ultrasounds, questionnaires, blood and other tests, participants were categorized into three groups: pre-existing disease (prevalent stroke and/or coronary heart disease), high risk group (no pre-existing disease, but prevalent diabetes, hypertension, plaques/shadowing, body mass index >= 30, current smoking, or hyperlipidemia), and a low risk group (no pre-existing disease, no plaques/shadowing, and no major elevated risk factors). Multivariable linear regression analyses modeled the common carotid artery diameter relationship with age.Results
Age was positively and significantly associated with common carotid artery diameter after risk factor adjustment in the overall sample, but age had a larger effect among persons with evidence of atherosclerosis (interaction p < 0.05). Each year of older age was associated with 0.03 mm larger diameter/year among persons with pre-existing disease, with 0.027 mm larger diameter/year in the high risk group, but only 0.017 mm/year among the low risk group. Results were qualitatively similar using plaques/shadowing status to indicate atherosclerosis severity.Conclusion
The significant impact of age on common carotid artery diameter among low risk, middle-aged, black and white men and women suggests arterial remodelling may occur in the absence of identified risk factors. The significantly larger impact of age among persons with, compared to persons without identified atherosclerosis or its risk factors, suggests that arterial remodelling may be an indicator of exposure duration. 相似文献4.
Magnus Dencker Carin Cronberg Sabine Damm Sven Valind Monica Wadbo 《Cardiovascular ultrasound》2008,6(1):1-3
Background
Stroke is the third most common cause of death in the UK and the largest single cause of severe disability. Each year more than 110,000 people in England suffer from a stroke which costs the National Health Service (NHS) over GBP2.8 billion. Thus, it is imperative that patients at risk be screened for underlying carotid artery atherosclerosis.Aim
To assess the role of carotid ultrasound in different carotid screening programmes.Methods
A literature overview was carried out by using PubMed search engine, to identify different carotid screening programmes that had used ultrasound scan as a screening tool.Results
It appears that the carotid ultrasound is an effective method for screening carotid artery disease in community as it effectively predicts the presence of stenosis with high accuracy. There is a need for primary care to recommend high risk patients for regular screening, to reduce stroke and transient ischemic attack (TIA) related morbidity and mortality.Conclusion
Screening programmes using carotid ultrasonography contribute to public health awareness and promotion which in long term could potentially benefit in disease prevention and essentially promote better standards of healthcare. 相似文献5.
Prashant Patel Rohan Biswas Daewoo Park Thomas J Cichonski Michael S Richards Jonathan M Rubin Sem Phan James Hamilton William F Weitzel 《Theoretical biology & medical modelling》2010,7(1):1-11
Background
Ultrasound elasticity imaging provides biomechanical and elastic properties of vascular tissue, with the potential to distinguish between tissue motion and tissue strain. To validate the ability of ultrasound elasticity imaging to predict structurally defined physical changes in tissue, strain measurement patterns during angioplasty in four bovine carotid artery pathology samples were compared to the measured physical characteristics of the tissue specimens.Methods
Using computational image-processing techniques, the circumferences of each bovine artery specimen were obtained from ultrasound and pathologic data.Results
Ultrasound-strain-based and pathology-based arterial circumference measurements were correlated with an R2 value of 0.94 (p = 0.03). The experimental elasticity imaging results confirmed the onset of deformation of an angioplasty procedure by indicating a consistent inflection point where vessel fibers were fully unfolded and vessel wall strain initiated.Conclusion
These results validate the ability of ultrasound elasticity imaging to measure localized mechanical changes in vascular tissue. 相似文献6.
Martí Juanola-Falgarona Jordi Salas-Salvadó Ramon Estruch Maria P Portillo Rosa Casas Jonatan Miranda Miguel A Martínez-González Mònica Bulló 《Cardiovascular diabetology》2013,12(1):1-9
Background
Macrovascular diseases (MVD) in type 2 diabetes mellitus (T2DM) are often considered all together, without discriminating the areas involved. The aim of our study was to analyse MVD prevalence in a large population of T2DM patients by dividing the cases into subgroups according to MVD sites (NMVD, no MVD; NSCS, non-significant carotid stenosis; CBVD, cerebrovascular disease; CAD, coronary artery disease; PAD, peripheral artery disease; PVD, polyvascular disease) and studying the anthropometric, clinical and laboratory parameters in each group.Methods
A diabetic outpatient cohort (n = 1199) was retrospectively studied. Demographic, clinical and laboratory parameters were included in analyses. A thorough cardiovascular history as documented by previous medical records (including medical and hospital records) and vascular laboratory studies (including standardised electrocardiogram, echocardiogram, provocative tests for cardiac ischaemia, ankle/brachial index, duplex ultrasonography of the carotid and lower limbs and, in selected cases, computed tomography angiography, carotid and peripheral arteriography and evaluation of transcutaneous oxygen pressure), was collected for all of the patients. Standardised procedures were used to assess microvascular complications as well as metabolic syndrome (Mets).Results
The unadjusted MVD prevalence was 46.4% among the participants. The majority of patients with MVD were in the PVD group. In the multivariate analysis, age, male sex and diabetes duration were independent risk factors for PAD and PVD (P < 0.01). A low HDL-C value was an independent risk factor in the CAD and PVD groups (P = 0.03). Very high frequencies of MetS were observed in the PAD and PVD groups (94.9 and 95.7% respectively). The most MetS diagnostic criteria were recorded among members of the CAD group (all or all-1 criteria were present in 73% of patients). The average age in the CAD group (64.5 y) was comparable to that of the NMVD group. Microvascular complications were more frequent in the PAD and PVD patients.Conclusion
Phenotypic heterogeneity is associated with different macrovascular complications in T2DM patients. These findings might have clinical implications for developing diagnostic and therapeutic strategies targeting type 2 diabetes. 相似文献7.
Background
Secondary treatment of arteriosclerosis may be applicable for the primary prevention of atherosclerosis in diabetic patients. This prospective, 2-year follow-up study was designed to determine the efficacy and safety of antiplatelet therapy in the prevention of atherosclerosis of diabetic subjects.Methods
Patients with type 2 diabetes and arteriosclerosis obliterans from the Eastern Asian countries were registered online and randomly assigned either to the aspirin group (81–100 mg/day) or the cilostazol group (100–200 mg/day) in this international, 2-year, prospective follow-up interventional study.Results
The primary study endpoint was changes in right and left maximum intima-media thickness of the common carotid artery. Secondary endpoints include changes in right and left maximum intima-media thickness of the internal carotid artery; semiquantitative evaluation of cerebral infarction by magnetic resonance imaging; cardiovascular events including sudden death, stroke, transient cerebral ischemic attacks, acute myocardial infarction, angina, and progression of arteriosclerosis obliterans; overall death; withdrawal; and change in ankle-brachial pressure index.Conclusion
This is the first study to use an online system that was developed in Asian countries for pooling data from an international clinical trial. These findings are expected to help in the prevention of diabetic atherosclerosis and subsequent cardiovascular and cerebrovascular disease. 相似文献8.
Kumar V Ramnarine Tim Hartshorne Yvonne Sensier May Naylor Joanne Walker A Ross Naylor Ronney B Panerai David H Evans 《Cardiovascular ultrasound》2003,1(1):1-15
Background
Studies suggest the physical and mechanical properties of vessel walls and plaque may be of clinical value in the diagnosis and treatment of cardiovascular atherosclerotic disease. The purpose of this pilot study was to investigate the potential clinical application of ultrasound Tissue Doppler Imaging (TDI) of Arterial Wall Motion (AWM) and to quantify simple wall motion indices in normal and diseased carotid arteries.Methods
224 normal and diseased carotid arteries (0–100% stenoses) were imaged in 126 patients (age 25–88 years, mean 68 ± 11). Longitudinal sections of the carotid bifurcation were imaged using a Philips HDI5000 scanner and L12-5 probe under optimized TDI settings. Temporal and spatial AWMs were analyzed to evaluate the vessel wall displacements and spatial gradients at peak systole averaged over 5 cardiac cycles.Results
AWM data were successfully extracted in 91% of cases. Within the carotid bifurcation/plaque region, the maximum wall dilation at peak systole ranged from -100 to 750 microns, mean 335 ± 138 microns. Maximum wall dilation spatial gradients ranged 0–0.49, mean 0.14 ± 0.08. The AWM parameters showed a wide variation and had poor correlation with stenoses severity. Case studies illustrated a variety of pertinent qualitative and quantitative wall motion features related to the biophysics of arterial disease.Conclusion
Our clinical experience, using a challenging but realistic imaging protocol, suggests the use of simple quantitative AWM measures may have limitations due to high variability. Despite this, pertinent features of AWM in normal and diseased arteries demonstrate the potential clinical benefit of the biomechanical information provided by TDI. 相似文献9.
Jeltsje S. Cnossen Rachel K. Morris Gerben ter Riet Ben W.J. Mol Joris A.M. van der Post Arri Coomarasamy Aeilko H. Zwinderman Stephen C. Robson Patrick J.E. Bindels Jos Kleijnen Khalid S. Khan 《CMAJ》2008,178(6):701-711
Background
Alterations in waveforms in the uterine artery are associated with the development of pre-eclampsia and intrauterine growth restriction. We investigated the predictive accuracy of all uterine artery Doppler indices for both conditions in the first and second trimesters.Methods
We identified relevant studies through searches of MEDLINE, EMBASE, the Cochrane Library and Medion databases (all records to April 2006) and by checking bibliographies of identified studies and consulting with experts. Four of us independently selected studies, extracted data and assessed study validity. We performed a bivariable meta-analysis of sensitivity and specificity and calculated likelihood ratios.Results
We identified 74 studies of pre-eclampsia (total 79 547 patients) and 61 studies of intrauterine growth restriction (total 41 131 patients). Uterine artery Doppler ultrasonography provided a more accurate prediction when performed in the second trimester than in the first-trimester. Most Doppler indices had poor predictive characteristics, but this varied with patient risk and outcome severity. An increased pulsatility index with notching was the best predictor of pre-eclampsia (positive likelihood ratio 21.0 among high-risk patients and 7.5 among low-risk patients). It was also the best predictor of overall (positive likelihood ratio 9.1) and severe (positive likelihood ratio 14.6) intrauterine growth restriction among low-risk patients.Interpretation
Abnormal uterine artery waveforms are a better predictor of pre-eclampsia than of intrauterine growth restriction. A pulsatility index, alone or combined with notching, is the most predictive Doppler index. These indices should be used in clinical practice. Future research should also concentrate on combining uterine artery Doppler ultrasonography with other tests.Pre-eclampsia and intrauterine growth restriction remain important causes of maternal and perinatal morbidity and mortality.1–3 Maternal complications of pre-eclampsia include coagulopathy, renal and liver failure, and stroke.1 Adults who were affected by intrauterine growth restriction in utero are at increased risk for cardiovascular disease, hypertension and type 2 diabetes.4,5Pre-eclampsia and intrauterine growth restriction are characterized by abnormal placenta formation,6 which results in inadequate uteroplacental blood flow. This has led to the idea of using Doppler ultrasonography to assess the velocity of uterine artery blood flow as part of routine ultrasound screening.7 Low end-diastolic velocities and an early diastolic notch characterize the waveforms of uterine artery blood flow in women who are not pregnant or are in their first trimester. Persistence of a diastolic notch (beyond 24 weeks'' gestation) or abnormal flow velocity ratios have been associated with inadequate trophoblast invasion.8Accurate prediction of pre-eclampsia and intrauterine growth restriction is crucial to allow judicious allocation of resources for monitoring and preventive treatment to improve maternal and perinatal outcomes.9,10 However, studies investigating the predictive accuracy of uterine artery Doppler indices (Box 1) have revealed considerably varied results. Thus, it is questionable whether uterine artery Doppler ultrasonography should be used as a predictive test. We undertook this review to investigate the accuracy of all uterine artery Doppler indices in predicting pre-eclampsia and intrauterine growth restriction.Open in a separate windowBox 1 相似文献10.
Background
To study the relationship between the intima-media thickness (IMT) of the carotid artery and the stage of chronic kidney disease (CKD) based on the estimated glomerular filtration rate (eGFR) and diabetic nephropathy graded by the urinary albumin excretion (UAE) in the patients with type 2 diabetes mellitus.Methods
A cross-sectional study was performed in 338 patients with type 2 diabetes mellitus. The carotid IMT was measured using an ultrasonographic examination.Results
The mean carotid IMT was 1.06 ± 0.27 mm, and 42% of the subjects showed IMT thickening (≥ 1.1 mm). Cerebrovascular disease and coronary heart disease were frequent in the patients with IMT thickening. The carotid IMT elevated significantly with the stage progression of CKD (0.87 ± 0.19 mm in stage 1, 1.02 ± 0.26 mm in stage 2, 1.11 ± 0.26 mm in stage 3, and 1.11 ± 0.27 mm in stage 4+5). However, the IMT was not significantly different among the various stages of diabetic nephropathy. The IMT was significantly greater in the diabetic patients with hypertension compared to those without hypertension. The IMT positively correlated with the age, the duration of diabetes mellitus, and the brachial-ankle pulse wave velocities (baPWV), and negatively correlated with the eGFR. In a stepwise multivariate regression analysis, the eGFR and the baPWV were independently associated with the carotid IMT.Conclusions
Our study is the first report showing a relationship between the carotid IMT and the renal parameters including eGFR and the stages of diabetic nephropathy with a confirmed association between the IMT and diabetic macroangiopathy. Our study further confirms the importance of intensive examinations for the early detection of atherosclerosis and positive treatments for hypertension, dyslipidaemia, obesity, as well as hyperglycaemia are necessary when a reduced eGFR is found in diabetic patients. 相似文献11.
G Galanti A Pizzi M Lucarelli L Stefani M Gianassi V Di Tante L Toncelli A Moretti F Del Furia 《Cardiovascular ultrasound》2008,6(1):1-5
Background
Previous studies demonstrated a modest association between C-Reactive Protein (CRP), stenosis of carotid artery, and carotid Intima-Media Thickness (IMT) in general population. During present study, we aimed to evaluate the relationship between High Sensitivity C-Reactive Protein (hsCRP) and Common Carotid Intima-Media Thickness (CCIMT) in patients who candidate for Coronary Artery Bypass Grafting (CABG).Methods
The study subjects were enrolled from patients with coronary arteries disease referred from Shahid Madani Hospital (Tabriz, Iran), who have been candidate for elective CABG from January 2005 to August 2007. The common carotid arteries were evaluated with high-resolution B-mode ultrasonography using a 7.5- MHz linear-array transducer to determine the IMT and grade of stenosis. Serum hsCRP level was measured using commercially available enzyme linked immunosorbent assay kit.Results
Finally, information of 176 CABG candidates was analysed. The mean age of participants was 62.71 ± 9.45 years with 1.63 male to female ratio. The mean of CCIMT was 0.69 ± 0.54 mm. Although there was no significant correlation between serum hsCRP level and CCIMT in patients without carotid stenosis (p=0.113, r=0.186), participants with common carotid artery stenosis had higher levels of serum hsCRP than participants without stenosis (2.42+/-1.30 vs. 1.20+/-0.97 mg/dl; p=0.009).Conclusion
Study results showed that there was no correlation between serum hsCRP level and CCIMT in patients without carotid stenosis, but patients with common carotid artery stenosis had higher levels of serum hsCRP than patients without stenosis. 相似文献12.
Background
Animal models and observations in human neonates suggest fetal exocrine pancreas vulnerability to reduced maternofetal blood flow. We investigated the relationship between superior mesenteric artery blood flow velocity (sma bfv) and exocrine pancreatic function, in a cohort of very low birth weight (VLBW) babies. Group 1: 9 babies < 3rd percentile for birth weight. Antenatally, all had absent or reversed diastolic flow on Doppler ultrasound of the umbilical artery (UA). Group2: 18 babies > 10th percentile for birth weight.Findings
All had Doppler ultrasound scan of the superior mesenteric artery (sma), by same operator (RMN), on day 1 of life before commencement of enteral feeding. Stool samples assayed for faecal chymotrypsin and weekly serum samples assayed for amylase and lipase (kinetic colorimetric assay) from days 1 to 14 of life. Growth restricted babies had significantly lower sma bfv values compared with appropriately grown preterm babies. Faecal chymotrypsin levels were also lower but this difference did not achieve statistical significance. Both groups had serum lipase levels detectable in adult concentrations. Serum amylase was undetectable in either group.Conclusion
Babies with previous in-utero blood flow redistribution may exhibit altered gut ontogeny with re-setting of mesenteric blood flow velocities and altered exocrine pancreatic function. 相似文献13.
Angelo Polito Zaccaria Ricci Luca Di Chiara Chiara Giorni Claudia Iacoella Stephen P Sanders Sergio Picardo 《Cardiovascular ultrasound》2006,4(1):1-11
Background
Transcranial Doppler Ultrasound (TCD) is a sensitive, real time tool for monitoring cerebral blood flow velocity (CBFV). This technique is fast, accurate, reproducible and noninvasive. In the setting of congenital heart surgery, TCD finds application in the evaluation of cerebral blood flow variations during cardiopulmonary bypass (CPB).Methodology
We performed a search on human studies published on the MEDLINE using the keyword "trans cranial Doppler" crossed with "pediatric cardiac surgery" AND "cardio pulmonary by pass", OR deep hypothermic cardiac arrest", OR "neurological monitoring".Discussion
Current scientific evidence suggests a good correlation between changes in cbral blood flow and mean cerebral artery (MCA) blood flow velocity. The introduction of Doppler technology has allowed an accurate monitorization of cerebral blood flow (CBF) during circulatory arrest and low-flow CPB. TCD has also been utilized in detecting cerebral emboli, improper cannulation or cross clamping of aortic arch vessels. Limitations of TCD routine utilization are represented by the need of a learning curve and some experience by the operators, as well as the need of implementing CBF informations with, for example, data on brain tissue oxygen delivery and consumption.Conclusion
In this light, TCD plays an essential role in multimodal neurological monitorization during CPB (Near Infrared Spectroscopy, TCD, processed electro encephalography) that, according to recent studies, can help to significantly improve neurological outcome after cardiac surgery in neonates and pediatric patients. 相似文献14.
Background
Multiples indices have been described using tissue Doppler imaging (DTI) capabilities. The aim of this study was to assess the capability of one or several regional DTI parameters in separating control from ischemic myocardium.Methods
Twenty-eight patients with acute myocardial infarction were imaged within 24-hour following an emergent coronary angioplasty. Seventeen controls without any coronary artery or myocardial disease were also explored. Global and regional left ventricular functions were assessed. High frame rate color DTI cineloop recordings were made in apical 4 and 2-chamber for subsequent analysis. Peak velocity during isovolumic contraction time (IVC), ejection time, isovolumic relaxation (IVR) and filling time were measured at the mitral annulus and the basal, mid and apical segments of each of the walls studied as well as peak systolic displacement and peak of strain.Results
DTI-analysis enabled us to discriminate between the 3 populations (controls, inferior and anterior AMI). Even in non-ischemic segments, velocities and displacements were reduced in the 2 AMI populations. Peak systolic displacement was the best parameter to discriminate controls from AMI groups (wall by wall, p was systematically < 0.01). The combination IVC + and IVR< 1 discriminated ischemic from non-ischemic segments with 82% sensitivity and 85% specificity.Conclusion
DTI-analysis appears to be valuable in ischemic heart disease assessment. Its clinical impact remains to be established. However this simple index might really help in intensive care unit routine practice. 相似文献15.
David S Molony Lucas H Timmins Olivia Y Hung Emad Rasoul-Arzrumly Habib Samady Don P Giddens 《Biomedical engineering online》2015,14(Z1):S2
Background
Wall shear stress (WSS) has been associated with sites of plaque localization and with changes in plaque composition in human coronary arteries. Different values have been suggested for categorizing WSS as low, physiologic or high; however, uncertainties in flow rates, both across subjects and within a given individual, can affect the classification of WSS and thus influence the observed relationships between local hemodynamics and plaque changes over time. This study examines the effects of uncertainties in flow rate boundary conditions upon WSS values and investigates the influence of this variability on the observed associations of WSS with changes in VH-IVUS derived plaque components.Methods
Three patients with coronary artery disease underwent baseline and 12 month follow-up angiography and virtual histology-intravascular ultrasound (VH-IVUS) measurements. Coronary artery models were reconstructed from the data and models with and without side-branches were created. Patient-specific Doppler ultrasound (DUS) data were employed as inflow boundary conditions and computational fluid dynamics was used to calculate the WSS in each model. Further, the influence of representative coronary artery flow waveforms upon WSS values was investigated and the concept of treating WSS using relative, rather than actual, values was explored.Results
Models that included side-branch outflows and subject-specific DUS velocities were considered to be the reference cases. Hemodynamic differences were caused by the exclusion of side-branches and by imposing alternative velocity waveforms. One patient with fewer side-branches and a scaled generic waveform had little deviation from the reference case, while another patient with several side-branches excluded showed much larger departures from the reference situation. Differences between models and the respective reference cases were reduced when data were analyzed using relative, rather than actual, WSS.Conclusions
When considering individual subjects, large variations in patient-specific flow rates and exclusion of multiple side-branches in computational models can cause significant differences in observed associations between plaque evolution and ranges of computed WSS. These differences may contribute to the large variability typically found among subjects in pooled populations. Relative WSS may be more useful than actual WSS as a correlative variable when there is a large degree of uncertainty in flow rate data.16.
Miguel Quintana Peter Lindell Samir K Saha Francesca del Furia Britta Lind Satish Govind Lars-Åke Brodin 《Cardiovascular ultrasound》2005,3(1):1-12
Background
Myocardial contrast echocardiography and coronary flow velocity pattern with a rapid diastolic deceleration time after percutaneous coronary intervention has been reported to be useful in assessing microvascular damage in patients with acute myocardial infarction.Aim
To evaluate myocardial contrast echocardiography with harmonic power Doppler imaging, coronary flow velocity reserve and coronary artery flow pattern in predicting functional recovery by using transthoracic echocardiography.Methods
Thirty patients with anterior acute myocardial infarction underwent myocardial contrast echocardiography at rest and during hyperemia and were quantitatively analyzed by the peak color pixel intensity ratio of the risk area to the control area (PIR). Coronary flow pattern was measured using transthoracic echocardiography in the distal portion of left anterior descending artery within 24 hours after recanalization and we assessed deceleration time of diastolic flow velocity. Coronary flow velocity reserve was calculated two weeks after acute myocardial infarction. Left ventricular end-diastolic volumes and ejection fraction by angiography were computed.Results
Pts were divided into 2 groups according to the deceleration time of coronary artery flow pattern (Group A; 20 pts with deceleration time ≧ 600 msec, Group B; 10 pts with deceleration time < 600 msec). In acute phase, there were no significant differences in left ventricular end-diastolic volume and ejection fraction (Left ventricular end-diastolic volume 112 ± 33 vs. 146 ± 38 ml, ejection fraction 50 ± 7 vs. 45 ± 9 %; group A vs. B). However, left ventricular end-diastolic volume in Group B was significantly larger than that in Group A (192 ± 39 vs. 114 ± 30 ml, p < 0.01), and ejection fraction in Group B was significantly lower than that in Group A (39 ± 9 vs. 52 ± 7%, p < 0.01) at 6 months. PIR and coronary flow velocity reserve of Group A were higher than Group B (PIR, at rest: 0.668 ± 0.178 vs. 0.248 ± 0.015, p < 0.0001: during hyperemia 0.725 ± 0.194 vs. 0.295 ± 0.107, p < 0.0001; coronary flow velocity reserve, 2.60 ± 0.80 vs. 1.31 ± 0.29, p = 0.0002, respectively).Conclusion
The preserved microvasculature detecting by myocardial contrast echocardiography and coronary flow velocity reserve is related to functional recovery after acute myocardial infarction. 相似文献17.
Daniel Kretzschmar Christian Jung Sylvia Otto Stephan Utschig Michael Hartmann Thomas Lehmann Atilla Yilmaz Tudor C P?rner Hans R Figulla Markus Ferrari 《Cardiovascular ultrasound》2012,10(1):1-5
Background
Embolization of atherosclerotic debris from the rupture of a vulnerable atherosclerotic plaque occurs iatrogenically during percutaneous coronary interventions (PCI) and can induce myocardial necrosis. These microembolizations are detected as high intensity transient signals (HITS) using intracoronary Doppler technology.Presentation of the hypothesis
In the presented study we will test if abciximab (ReoPro?) infusion reduces high intensity transient signals in patients with stable angina pectoris undergoing PCI in comparison to standard therapy alone.Testing the hypothesis
The High Intensity Transient Signals ReoPro? (HITS-RP) study will enroll 60 patients. It is a prospective, single center, randomized, double-blinded, controlled trial. The study is designed to compare the efficacy of intravenous abciximab administration for reduction of microembolization during elective PCI. Patients will be randomized in a 1:1 fashion to abciximab or placebo infusion. The primary end point of the HITS-RP-Study is the number of HITS during PCI measured by intracoronary Doppler wire. Secondary endpoints are bleeding complications, elevation of cardiac biomarkers or ECG changes after percutaneous coronary interventions, changes in coronary flow velocity reserve, hs-CRP elevation, any major adverse cardio-vascular event during one month follow-up.Implications of the hypothesis
The HITS-RP-Study addresses important questions regarding the efficacy of intravenous abciximab administration in reducing microembolization and periprocedural complications in stable angina pectoris patients undergoing PCI.Trial registration
The trial is registered under http://www.drks-neu.uniklinik-freiburg.de/drks_web/:DRKS00000603. 相似文献18.
Purpose
to determine diagnosis and prognosis value of MRI in Peyronie’s disease.Material and Methods
thirty one penile MR examinations have been performed in 28 patients aged between 21 and 73. (1 tesla; surface coil; sagittal SET1, axial SET2 weighted, T1 before and after Gadolinium)Results
Conclusion
MRI can be helpfull in the pretreatment assessment and int he follow-up of Peyronie’s disease. 相似文献19.
Background
There are sex differences in the risk of development of cardiovascular disease (CVD). According to the developmental origins of health and disease paradigm (DOHaD), CVD originates in fetal life. This study examines fetal sex differences in cardiovascular development in utero.Methods
In 1028 pregnant women, we assessed fetal circulation using pulsed wave Doppler examinations between 28 and 34 weeks gestation. To test associations between fetal sex and fetal circulation measurements, linear regression models were used adjusting for fetal size, gestational age, and fetal heart rate.Results
A higher pulsatility index in the ductus venosus was observed in male fetuses compared to female fetuses (difference 0.02, 95 % CI 0.01; 0.05) with a lower E/A ratio of the tricuspid (difference ?0.01, 95 % CI ?0.03; ?0.00) and mitral (difference ?0.02, 95 % CI ?0.03; ?0.01) valves. This was mainly determined by differences in the E wave of the tricuspid and mitral valves (differences ?1.02, 95 % CI ?1.81; ?0.24 and ?1.28, 95 % CI ?2.11; ?0.46, respectively). Also in males, a lower peak systolic velocity was seen in the pulmonary artery (difference ?1.33, 95 % CI ?2.63; ?0.03) with a similar lower trend regarding peak systolic velocity in the ascending aorta.Conclusions
Male fetuses exhibit an increased preload and reduced afterload conditions compared to females. While it is difficult to relate these measurements to exact cardiac function, our findings strongly suggest that the known differences in cardiovascular performance between the sexes already start in utero.20.
Nima Taha Jing Zhang Reza Rafie Rupesh Ranjan Salima Qamruddin Tasneem Z Naqvi 《Cardiovascular ultrasound》2011,9(1):1-12