Cardiovascular circulation time

The two relevant patient-derived factors that affect contrast enhancement are body weight and cardiac output (or cardiovascular circulation time). All other patient-related effects on contrast attenuation are negligible. 

Global cardiac function (measured as cardiac output or cardiovascular circulation time) critically affects the timing of contrast attenuation (Bae et ah 1998b). Decreased cardiac function results in a delay of peak vascular and parenchymal attenuation. 

The predominant actions of phenylephrine are on the cardiovascular system. Parenteral administration causes a rise in systolic and diastolic pressures due to peripheral vasoconstriction. Accompanying the pressor response to phenylephrine is a marked reflex bradycardia that can be blocked by atropine after atropine, large doses of the peripheral resistance is considerably increased. Circulation time is slightly prolonged, and venous pressure is slightly increased venous constriction is not marked. Most vascular beds are constricted renal, splanchnic, cutaneous, and limb blood flows are reduced, but coronary blood flow is increased. Pulmonary vessels are constricted, and pulmonary arterial pressure is raised. 

Circulatory disorders In general, acute liver failure is initially accompanied by hyperdynamic circulation. During the further course, approx. 80% of patients develop hypotension, which above all results in a considerable reduction in hepatic, cerebral and renal perfusion. At the same time, peripheral vasodilation is usually witnessed. Bradycardia, generally resulting from cerebral oedema, worsens the cardiovascular conditions and is considered to be a poor prognostic sign. Ultimately, the patient does not respond to volume expansion and catecholamines. 

A molecule of bile salt may circulate many times per day through the enterohepatic system. This pnfcess can be interrupted by consumption of a special powdered resin that binds to the bile salts. Neither the resin itself nor the complex of resin and bile salt is absorbed by the iiitestines. Consequently, the complex is excreted in the feces. This resin, cholestyramine, is a synthebe compound used as a drug to lower serum cholesterol levels in the treatment of cardiovascular disease. 

Fentanyl [437-38-7] (Subhmaze, Leptanal), C22H2gN20, (9) has been extensively used since its introduction into clinical practice in the 1960s (119). Because of its potency, which is 50—100 times that of morphine, a rapid onset of action and a short duration, its use as an iv anesthetic is widespread The short duration results from redistribution from the brain to other tissues, rather than elimination. It does, however, have the usual opiate disadvantages respiratory depression, chest wall rigidity, nausea, and bradycardia. Fentanyl has an extremely wide therapeutic ratio. The size of the dose influences its duration of action which, after iv administration, may last from approximately 30 min to 2 to 3 h (120,121). In cardiac surgery fentanji is administered in very laige doses to produce profound analgesia and suppress cardiovascular reflex responses. This technique is particulady useful for patients with compromised circulation where any increase in cardiac demand could precipitate myocardial ischemia (122). 

Taruttis, A., et al. Real-time imaging of cardiovascular dynamics and circulating gold nanorods with multispectral optoacoustic tomography. Optics Express 18(19), 19592-19602 (2010)... 

In a 2014 paper published in the journal Circulation, Menon and Lincoff (2014) detailed ongoing cardiovascular outcome trials at the time of their paper s... 

Hot-wire anemometers have traditionally been applied in the fields of experimental fluid mechanics and aerospace engineering. Despite the possibilities to measure real-time physical parameters such as temperature, velocity, flow rates, and shear stress, the spatial resolution is limited to the device dimension. The advent of MicroElectroMe-chanical system (MEMS) and nano-scale thermal sensors has revolutionized the spatial and temporal resolution critical to gain entry into micro-fluidics, micro-circulation, biomedical sciences, and cardiovascular medicine. These micro/nano devices are fabricated with the Semiconductor-... 

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