Impact of Transient Hypotension on Regional Cerebral Blood Flow in Humans

We examined the impact of progressive hypotension with and without hypocapnia on regional extracranial cerebral blood flow and intra-cranial velocities. Participants underwent progressive lower-body negative pressure until pre-syncope to inflict hypotension. End-tidal carbon dioxide was clamped at baseline levels (isocapnic trial) or uncontrolled (poikilocapnic trial). Middle and posterior cerebral artery blood velocities (transcranial Doppler), heart rate, blood pressure and end-tidal carbon dioxide were obtained continuously. Measurements of internal carotid artery and vertebral artery blood flow were also obtained. Overall, blood pressure was reduced by ~20% from baseline in both trials (P
Source: Clinical Science - Category: Biomedical Science Authors: Source Type: research

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Conclusions: Assessment of flavin, a marker of mitochondrial complex I injury, in the perfusate provides a fast prediction of liver graft function and loss during ex situ MP before implantation. This finding may have high clinical relevance, as liver grafts from extended DBD or DCD donors carry considerable risks for recipients. On-line estimation of outcome before implantation would therefore substantially increase safe utilization of liver grafts.
Source: Annals of Surgery - Category: Surgery Tags: ESA PAPERS Source Type: research
Objective: The aim of this study was to evaluate sequential hypothermic and normothermic machine perfusion (NMP) as a tool to resuscitate and assess viability of initially declined donor livers to enable safe transplantation. Summary Background Data: Machine perfusion is increasingly used to resuscitate and test the function of donor livers. Although (dual) hypothermic oxygenated machine perfusion ([D]HOPE) resuscitates livers after cold storage, NMP enables assessment of hepatobiliary function. Methods: In a prospective clinical trial, nationwide declined livers were subjected to ex situ NMP (viability assessment ...
Source: Annals of Surgery - Category: Surgery Tags: ESA PAPERS Source Type: research
CONCLUSIONS Beyond a risk assessment scale, providers should consider other factors, such as comorbidities, which can predispose patients to HPI development.
Source: Advances in Skin and Wound Care - Category: Dermatology Tags: FEATURES: ORIGINAL INVESTIGATION Source Type: research
ConclusionsThese results demonstrate the practical utility of HSI for the real-time detection of cerebral ischemia in rats. By providing rapid assessment of brain tissue perfusion, HSI may help doctors recognize ischemic regions quickly and precisely during surgery as well as have great utility in the experimental process.
Source: Journal of Neuroscience Methods - Category: Neuroscience Source Type: research
AbstractThe purpose of this study was to evaluate the feasibility of the stenosis-related quantitative perfusion ratio (QPR) for detecting hemodynamically significant coronary artery disease (CAD). Twenty-seven patients were retrospectively enrolled. All patients underwent dynamic myocardial computed tomography perfusion (CTP) and coronary computed tomography angiography (CTA) before invasive coronary angiography (ICA) measuring the fractional flow reserve (FFR). Coronary lesions with FFR  ≤ 0.8 were defined as hemodynamically significant CAD. The myocardial blood flow (MBF) was calculated using dynamic CT...
Source: Cardiovascular Intervention and Therapeutics - Category: Cardiology Source Type: research
Eisenmenger syndrome refers to the elevation of pulmonary arterial pressure to the systemic level caused by an increased pulmonary vascular resistance with right-to-left shunt through an intracardiac or aortopulmonary communication. A 36-year-old woman with Eisenmenger syndrome due to patent ductus arteriosus underwent 99mTc-MAA lung perfusion scintigraphy to evaluate right-to-left shunt. Whole-body imaging visualized extrapulmonary activity in both kidneys, spleen, and intestinal tract, confirming the presence of right-to-left shunt. Accumulation in the brain was visible but much weaker compared with that in the body trun...
Source: Clinical Nuclear Medicine - Category: Nuclear Medicine Tags: Interesting Images Source Type: research
We report the case of a 66-year-old woman who underwent 1-day stress/rest myocardial perfusion imaging (MPI) for coronary artery disease (CAD) screening. Relative MPI analysis was normal, whereas low-dose CT showed high calcium score. Myocardial blood flow and flow reserve were strongly impaired in all territories. Coronary angiography confirmed extended CAD. Flow parameters derived from cadmium-zinc-telluride SPECT MPI acquisition and calcium scoring can improve diagnostic accuracy and confidence of CAD.
Source: Clinical Nuclear Medicine - Category: Nuclear Medicine Tags: Interesting Images Source Type: research
In this study, we evaluated and compared the level of myocardial ischaemia caused by cardiac syndrome X (CSX) and coronary slow flow (CSF) with single photon emission computed tomography myocardial perfusion imaging (SPECT-MPI), and determined if changes in the level of myocardial ischaemia exist in CSF and CSX cases according to thrombolysis in myocardial infarction frame count (TFC). Materials and methods The study population consisted of 66 patients with CSF and 78 angiographically normal patients (36 of them with CSX and 42 of them healthy controls). The coronary flow rates of all patients were documented using TFC....
Source: Nuclear Medicine Communications - Category: Nuclear Medicine Tags: Original Articles Source Type: research
Conclusions The quantitative-gated SPECT and quantitative perfusion SPECT values obtained from images with shorter acquisition times correlated with the values obtained from images with a reference acquisition time of 65 s/view; however, tracer-specific predisposition should be considered. These findings suggest that it is possible to reduce acquisition time when performing simultaneous 99mTc-tetrofosmin/123I-β-methyl-p-iodophenyl pentadecanoic acid dual-tracer imaging with the novel cadmium–zinc–telluride scanner.
Source: Nuclear Medicine Communications - Category: Nuclear Medicine Tags: Original Articles Source Type: research
AbstractAlthough congestion is considered to be the main reason for hospital admission in patients with acute heart failure, a simplistic view considering idro saline retention and total body volume accumulation did not provide convincing data. Clinical congestion occurrence is often the tip of the iceberg of several different mechanisms ranging from increased filling pressure to extravascular fluid accumulation and blood flow redistribution. Therefore, the clinical evaluation is often restricted to a simple physical examination including few and inaccurate signs and symptoms. This superficial approach has led to contradic...
Source: Heart Failure Reviews - Category: Cardiology Source Type: research
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