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Doppler Study (doppler + study)
Selected AbstractsRegional Response of Myocardial Acceleration During Isovolumic Contraction During Dobutamine Stress Echocardiography: A Color Tissue Doppler Study and Comparison with Angiocardiographic FindingsECHOCARDIOGRAPHY, Issue 10 2005Linda B. Pauliks M.D. Background: Color tissue Doppler imaging permits noninvasive quantitation of regional wall motion. In experimental studies, a new marker, the slope of the isovolumic contraction wave, isovolumic acceleration (IVA) was more insensitive to ventricular loading conditions than myocardial velocities. This study compared the regional response IVA to dobutamine stress echocardiography to angiographic findings. Methods: The Myocardial Doppler in Stress Echocardiography (MYDISE) study prospectively recruited 149 consecutive patients with chest pain for dobutamine stress tissue Doppler echocardiography prior to coronary angiography. This color tissue Doppler database was analyzed for IVA in 1192 basal and mid segments at rest and again at peak stress. Angiographic findings were compared to IVA and peak systolic velocities (PSV) in corresponding cardiac segments. The diagnostic accuracy of IVA to predict coronary artery stenosis was determined using cut-off values for three representative segments and with the MYDISE diagnostic model including eight segments. Results: Regional IVA increased in a dose-dependent manner during dobutamine infusion. The response was blunted in the supply territory of stenosed coronary artery branches. IVA performed slightly better than PSV as single marker for coronary artery stenosis. A diagnostic model incorporating IVA and PSV was 85,95% accurate (area under receiver operating characterstic curves). Conclusions: Regional changes of isovolumic acceleration during dobutamine stress echocardiography reflect regional wall motion and can be used to predict coronary artery stenosis with similar accuracy as a model based on systolic myocardial velocities. As a single marker, IVA performed better than myocardial velocities. (ECHOCARDIOGRAPHY, Volume 22, November 2005) [source] Segmental Differences of Impaired Diastolic Relaxation Following Cardiopulmonary Bypass Surgery in Children: A Tissue Doppler StudyARTIFICIAL ORGANS, Issue 11 2009Linda B. Pauliks Abstract Impaired myocardial relaxation is an important aftereffect of cardiopulmonary bypass (CPB). Infants with their immature calcium metabolism may be particularly vulnerable. However, it has been difficult to quantitate diastolic dysfunction clinically. This study used tissue Doppler to measure regional diastolic myocardial velocities in 31 pediatric patients undergoing open heart surgery. Color tissue Doppler images were acquired in the operating room before and 8 and 24 h post CPB surgery. Early (E) and atrial (A) diastolic velocities were determined. Long axis motion was assessed from apical views near the mitral and tricuspid rings and radial wall motion from the parasternal view. The study included 31 children aged 3.6 ± 4.4 years (6 days to 16 years), with a mean weight of 14.7 ± 13.7 kg and body surface area of 0.59 ± 0.35 m2. Tissue Doppler analysis of regional wall motion revealed abnormal left ventricle (LV) and right ventricle (RV) diastolic relaxation in the early postoperative phase after CPB. Initially, all segments were significantly altered, but by 24 h, regional differences became apparent: LV radial wall motion was recovered, while longitudinal fibers in LV and RV appeared to be less resilient. RV myocardial mechanics were most abnormal. Tissue Doppler analysis may deepen our understanding of myocardial recovery and offers a sensitive tool to compare different cardioprotective strategies. [source] Effects of physiological aging and cerebrovascular risk factors on the hemodynamic response to brain activation: a functional transcranial Doppler studyEUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2007K. Gröschel The influence of the vascular system on the coupling of cerebral blood flow (CBF) to focal brain activation during aging is incompletely understood. Using functional transcranial Doppler sonography and a hypercapnic challenge as a marker of intact cerebral vasoreactivity, we determined CBF velocity (CBFV) changes in response to a language and arithmetic task in a group of 43 healthy young subjects (mean age 32 ± 8.6 years), 18 healthy old subjects (mean age 64 ± 9.8 years) and 29 old subjects with risk factors for an atherosclerosis (mean age 69 ± 8.4 years). Despite a similar performance during the cognitive tasks the CBFV changes were significantly lower in the group of old subjects with vascular risk factors compared with the healthy young and old subjects. Similarly, the CBFV changes during hypercapnia were significantly lower in the group of old subjects with vascular risk factors compared with the healthy young and old subjects. In contrast, both cognitive tasks and hypercapnia produced comparable CBFV changes in the group of healthy young and old subjects. These results suggest that the hemodynamic response to neuronal activation is unaffected by aging alone, whereas the presence of cardiovascular risk factors significantly diminishes the capability of cerebral vessels to react to vasodilating stimuli. [source] Evaluation of the hepatic artery anastomosis by intraoperative sonography with high-frequency transducer in right-lobe graft living donor liver transplantationJOURNAL OF CLINICAL ULTRASOUND, Issue 1 2010Han Song Mun MD Abstract Objective To describe the usefulness of intraoperative ultrasonography (IOUS) with high-frequency transducer in living donor liver transplantation (LDLT) using right-lobe graft (RLG). Method This retrospective study was approved by our institutional review board. We performed IOUS in 22 patients (17 men and 5 women, aged 51 ± 9.0 years) during LDLT with RLG using a Sequoia 512 scanner with an 8,12-MHz linear transducer. Hepatic artery (HA) anastomosis was identified on gray-scale US, and the diameter and percentage of stenosis of the anastomosis were measured. The HA was evaluated to detect thrombus or dissection in the region of anastomosis. Doppler study of the graft HA was also performed. Patients were divided into those with and without abnormalities, including thrombosis, dissection, and abnormal Doppler parameters (peak systolic velocity < 30 cm/s or > 2 m/s, resistance index < 0.5, and systolic acceleration time > 80 msec). Result On gray-scale and Doppler IOUS study, abnormalities were found in 10 of 22 patients. Diagnoses were anastomotic stenosis (n = 2), celiac stenosis (n = 1), compromise of HA inflow due to systemic hypotension (n = 1), HA thrombosis (n = 2), and HA dissection (n = 4). Re-anastomoses were done in 3 case (2 stenoses and 1 thrombosis). Uneventful postoperative recovery occurred in the other 7 patients without re-anastomosis. Conclusion IOUS with high-frequency transducer is a useful method to make an early diagnosis of HA complications of LDLT with RLG. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound, 2010 [source] The effects of copper contraceptive intrauterine device on the uterine blood flow: A prospective transvaginal Doppler studyJOURNAL OF CLINICAL ULTRASOUND, Issue 7 2009Nuray Yigit MD Abstract Purpose. To evaluate the hemodynamic changes by transvaginal color Doppler sonography (CDS) in the uterine vascular bed after the insertion of a contraceptive intrauterine device (CIUD) and to investigate whether those CDS findings could predict potential side effects, such as dysmenorrhea and abnormal bleeding. Method. Pulsatility index (PI), resistance index, and systole/diastole ratio (S/D) were measured in the uterine artery and its myometrial branches on 28 patients before and after the insertion of copper IUD, and a correlation with dysmenorrhea and abnormal bleeding was investigated. Result. PI and S/D values in the uterine artery increased significantly after the insertion of the CIUD (p < 0.05). Patients with increased bleeding scores after insertion of CIUD had significantly lower uterine artery PI compared with those without increased bleeding scores (p < 0.05). No statistically significant difference was detected in the Doppler flow parameters regarding dysmenorrhea scores. Conclusion. Low uterine artery PI values recorded in the early phase of the menstrual cycle in patients with a CIUD were associated with an increased bleeding risk. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound 2009 [source] Surgical closure of patent ductus arteriosus reduces the cerebral tissue oxygenation index in preterm infants: a near-infrared spectroscopy and Doppler studyPEDIATRICS INTERNATIONAL, Issue 3 2006PATRIZIA ZARAMELLA Abstract Background: The aim of this study was to investigate the effects of patent ductus arteriosus (PDA) ligature on cerebral oxygen saturation, cerebral blood volume (CBV) and cerebral blood flow velocity by means of near-infrared spectroscopy (NIRS) and transcranial Doppler simultaneous examinations. Methods: This is an observational study considering 16 babies of gestational age 24,34 weeks diagnosed with PDA who underwent surgical ligation. The cerebral oxygen saturation, CBV and blood gases values were obtained 35 min before ligation, so also around the 14th and 27th min after the clip's insertion. Results: Cerebral oxygen saturation, measured as tissue oxygenation index (TOI), decreased significantly after PDA ligation from a basal value of 61.1 (3.8) before surgery to 56.6 (3.3) and 55.8 (2.6)%, for the 14th and 27th min, respectively (P < 0.04). CBV before and after clipping was unvaried. A negative correlation was found between ,pH and ,CBV after ligation (R = 0.52, P = 0.03), whilst a positive correlation was found between ,CBV and ,PaCO2 (R = 0.62, P = 0.009). pH increased at the 27th min post-ligation. Conclusions: NIRS is a tool for obtaining information on cerebral oxygen saturation and CBV changes during surgical PDA ligation at the bedside. A fall in TOI suggests an increased oxygen extraction during PDA surgery. The lack of increase in ,CBV or in diastolic flow velocity show that the PDA before the clipping did not limit cerebral blood flow, the drop in TOI suggests increased oxygen consumption over the clip and the need for accurate monitoring of oxygen utilization after the surgical treatment. [source] Endothelial cell expression of adhesion molecules is induced by fetal plasma from pregnancies with umbilical placental vascular diseaseBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 7 2002Xin Wang Objective To test the hypothesis that local production with spill into the fetal circulation of factor(s) injurious to endothelium is responsible for the vascular pathology present when the umbilical artery Doppler study is abnormal. Expression of adhesion molecules is a feature of endothelial cell activation. Design Case,control study. Setting University teaching hospital. Samples Fetal plasma was collected from 27 normal pregnancies, 39 pregnancies with umbilical placental vascular disease defined by abnormal umbilical artery Doppler and 11 pregnancies with pre-eclampsia and normal umbilical artery Doppler. Methods Isolated and cultured human umbilical vein endothelial cells from normal pregnancies were incubated with fetal plasma from three study groups. mRNA expression of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and platelet-endothelial cell adhesion molecule-1 (PECAM-1) were assessed by reverse transcription-polymerase chain reaction. To confirm the occurrence of this in vivo, we measured the levels of soluble fractions of sICAM-1, sVCAM-1 and sPECAM-1 in the fetal circulation in the fetal plasma used for endothelial cell incubation. Results The mRNA expression of ICAM-1 [median 1.1 (interquartile range 0.5,1.9) vs 0.7 (0.3,1.2), P < 0.05] and PECAM-1 [2.1 (1.2,3.0) vs 1.5 (0.7,2.1), P < 0.05] was significantly higher following incubation with fetal plasma from umbilical placental vascular disease compared with the normal group. There was no difference in the expression of VCAM-1 [1.2 (0.9,1.8) vs 1.1 (0.8,1.6), ns]. The group with maternal pre-eclampsia and normal umbilical artery Doppler did not differ from the normal group. In the umbilical placental vascular disease group, the results were similar in the presence or absence of pre-eclampsia. For soluble fractions of the adhesion molecules released into the fetal circulation, we found the levels (ng/mL) of sICAM-1 [median 248.5 (interquartile range 197.3,315.7) vs 174.2 (144.5,212.9), P < 0.05] and sPECAM-1 [9.3 (6.2,11.1) vs 6.1 (5.4,7.7), P < 0.05] in fetal plasma to be significantly increased in the presence of umbilical placental vascular disease compared with the normal. Conclusions Vascular disease in the fetal umbilical placental circulation is associated with an elevation in mRNA expression by endothelial cells of ICAM-1 and PECAM-1. Our study provides evidence for endothelial cell activation and dysfunction in umbilical placental vascular disease. We speculate that the plasma factor(s) affecting the vessels of the umbilical villous tree is locally released by the trophoblast. The occurrence of the maternal syndrome of pre-eclampsia appears to be independent of this. [source] Hyperoxia-induced arterial compliance decrease in healthy manCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 1 2005Pascal Rossi Summary Introduction:, Oxygen therapy is commonly used in emergency department and intensive care units without careful evaluation of its effects, especially on the haemodynamics and artery characteristics. Materials and methods:, A prospective laboratory study evaluated brachial circulatory effects of normobaric hyperoxia using ultrasonography-Doppler. The study was set in a hospital research laboratory. The subjects were thirteen healthy volunteers. Investigations were performed under normal air ventilation and after 20 min of hyperoxic mixture ventilation using a high concentration mask. Two dimensional images and brachial blood flow velocities were recorded using ultrasonography and pulsed Doppler to study changes in cross sectional area, blood flow, resistance index, and cross-sectional compliance coefficient. Results:, During hyperoxic exposure, mean PaO2 was 372 ± 21 mmHg. A significant decrease of heart rate was observed. Arterial pressures (systolic and diastolic arterial pressures) were not modified. A decrease of cross sectional areas at end diastole and end systole was observed. Pulsed Doppler study showed a decrease of brachial artery blood flow and an increase of the resistance index. Furthermore, a decrease of the cross-sectional compliance coefficient was observed during hyperoxic exposure in all subjects. Conclusion:, This study using two-dimensional ultrasonography and pulsed Doppler could demonstrate an increase in brachial arterial tone and a decrease in brachial blood flow under normobaric hyperoxia. [source] | ||||||||||