Aims: This study analyses the changes in cerebral blood flow (CBF) velocity occurring in the near syncopal phase of head-up tilt test (HUT) to determine whether their appearance during the premonitory symptoms permits the differentiation of the different types of haemodynamic response.
Methods And Results: Six hundred and nineteen patients aged 35.9 +/- 16.4 with a prior history of syncope (55%) or presyncope (45%) were studied. Head-up tilt test was positive in 585 patients. The test was interrupted before syncope, once hypotension was evident and CBF changed. A vasovagal reaction (VVR) was observed in 245 patients. They had a 59% fall in diastolic CBF velocity, whereas systolic CBF velocity decreased by 12%. Postural orthostatic tachycardia syndrome (POTS) was observed in 82, systolic and diastolic CBF velocity decreased 44 and 60%, respectively. A similar response was observed in 258 patients with the orthostatic intolerance (OI) pattern. No significant changes were observed in the negative group.
Conclusion: Patients with VVR had changes in CBF velocity, which are different from those presented by patients with POTS and OI pattern. Cerebral blood flow monitoring is useful to increase the yield of HUT and may allow early interruption before syncope occurs, reducing patient discomfort.
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http://dx.doi.org/10.1093/europace/eul001 | DOI Listing |
Brain Res Bull
January 2025
Department of Radiology, Beijing Friendship Hospital, Capital Medical University, 100050, Beijing, China; Precision and Intelligence Medical Imaging Lab, Beijing Friendship Hospital, Capital Medical University, 100050, Beijing, China. Electronic address:
Purpose: Dobutamine, a sympathomimetic agent, is widely used clinically, influencing cardiac output, heart rate (HR), and blood pressure (BP), which may impact cerebral blood flow (CBF), critical for brain metabolism. However, the effects of dobutamine on CBF and internal carotid artery (ICA) blood flow remain unclear, with contradictory reported in both clinical and animal studies. It is necessary to investigate the effects of dobutamine on cervical and cerebral hemodynamics.
View Article and Find Full Text PDFHealthcare (Basel)
December 2024
Stichting Cardio Zorg, Kraayveld 5, 1171 JE Badhoevedorp, The Netherlands.
Introduction: Orthostatic intolerance is highly prevalent in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and is caused by an abnormal reduction in cerebral blood flow (CBF). In healthy controls (HCs), the regulation of CBF is complex and cardiac output (CO) is an important determinant of CBF: a review showed that a 30% reduction in CO results in a 10% reduction in CBF. In previous and separate ME/CFS studies, we showed that CO and CBF decreased to a similar extent during tilt testing.
View Article and Find Full Text PDFFront Neurol
December 2024
Department of Neurosurgery, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.
Objective: To evaluate postoperative cerebral perfusion changes and their influencing factors in carotid endarterectomy (CEA) patients by integrating multimodal monitoring methods, including cerebral regional oxygen saturation (rSO), carotid ultrasound (CU), computed tomographic angiography (CTA), and computed tomographic perfusion imaging (CTP), with computational fluid dynamics (CFD) assessment.
Methods: We conducted a cohort study on patients with internal carotid artery (ICA) stenosis undergoing CEA at our institution. Pre- and postoperative assessments included CU, CTA, CTP, and rSO monitoring.
J Cereb Blood Flow Metab
December 2024
Department of Biomedical Engineering, State University of New York at Stony Brook, Stony Brook, NY, USA.
Alzheimer's disease (AD), a neurodegenerative disorder with progressive cognitive decline, remains clinically challenging with limited understanding of etiology and interventions. Clinical studies have reported vascular defects prior to other pathological manifestations of AD, leading to the "Vascular Hypothesis" for the disorder. However, assessments of cerebral vasculature in AD rodent models have been constrained by limited spatiotemporal resolution or field of view of conventional imaging.
View Article and Find Full Text PDFLab Anim
December 2024
Cooperative Division of Veterinary Sciences, Tokyo University of Agriculture and Technology, Tokyo, Japan.
This study aimed to investigate the impact of selected analysis conditions on blood flow values and color maps in canine brain perfusion computed tomography (PCT) and to propose optimal analysis conditions. Dynamic computed tomography imaging was performed on six beagle dogs. Color maps were generated using a combination of analysis algorithms (box-modulation transfer function (Box-MTF) and singular value deconvolution plus (SVD+) methods), slice thicknesses (4.
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