SUMMARY Cardiac output determined by Doppler echocardiography was compared with that determined by thermodilution at rest and during dobutamine infusion in 10 patients (group A) and by the Fick method at rest in 11 patients (group B). All patients had angina pectoris without valvular heart disease. Maximum spatial blood velocity and cross sectional aortic area were estimated by the Doppler technique and echocardiography. Cardiac output was calculated by multiplying blood velocity by aortic area at various levels in the ascending aorta. The best correlation of cardiac output between the invasive and non-invasive methods was obtained when maximum velocity in the aortic root and the aortic orifice area were used in the calculations. Cardiac output was considerably overestimated when area measurements in the aortic root were used.The Doppler technique for measuring blood velocities in the human aorta was first reported by Light.' Later several investigators attempted to estimate cardiac output by multiplying the velocity by the cross sectional area of the aorta,2-4 but the results have been confficting.5-7 One important factor is that there is no general agreement on where in the aorta the area or the blood velocity should be measured. The present investigation was, therefore, designed to elucidate this problem by comparing the results of the non-invasive method with those of two generally accepted invasive methods-thermodilution and the Fick method. Patients and methods STUDY POPULATIONTwenty one patients (18 men, three women, mean age 53 (range 41-64) years with angina pectoris who were
BackgroundEffective treatment of stroke is time dependent. Pre-hospital management is an important link in reducing the time from occurrence of stroke symptoms to effective treatment. The aim of this study was to evaluate time used by emergency medical services (EMS) for stroke patients during a five-year period in order to identify potential delays and evaluate the reorganization of EMS in Copenhagen in 2009.MethodsWe performed a retrospective analysis of ambulance records from stroke patients suitable for thrombolysis from 1 January 2006 to 7 July 2011. We noted response time from dispatch of the ambulance to arrival at the scene, on-scene time and transport time to the hospital—in total, alarm-to-door time. In addition, we noted baseline characteristics.ResultsWe reviewed 481 records (58% male, median age 66 years). The median (IQR) alarm-to-door time in minutes was 41 (33–52), of which 18 (12–24) minutes were spent on scene. Response time was reduced from the period before to the period after reorganization (7 vs. 5 minutes, p <0.001). In a linear multiple regression model, higher patient age and longer distance to the hospital correlated with significantly longer transportation time (p <0.001).ConclusionsThis study shows an unchanged alarm-to-door time of 41 minutes over a five-year period. Response time, but not total alarm-to-door time, was reduced during the five years. On-scene time constituted nearly half of the total alarm-to-door time and is thus a point of focus for improvement.
Background: Cerebral autoregulation (CA) is the brain's ability to always maintain an adequate and relatively constant blood supply, which is often impaired in cerebrovascular diseases. Near-infrared spectroscopy (NIRS) examines oxygenated hemoglobin (OxyHb) in the cerebral cortex. Low-and very low-frequency oscillations (LFOs ≈ 0.1 Hz and VLFOs ≈ 0.05 to 0.01 Hz) in OxyHb have been proposed to reflect CA. Aim: To systematically review published results on OxyHb LFOs and VLFOs in cerebrovascular diseases and related conditions measured with NIRS. Approach: A systematic search was performed in the MEDLINE database, which generated 36 studies relevant for inclusion. Results: Healthy people have relatively stable LFOs. LFO amplitude seems to reflect myogenic CA being decreased by vasomotor paralysis in stroke, by smooth muscle damage or as compensatory action in other conditions but can also be influenced by the sympathetic tone. VLFO amplitude is believed to reflect neurogenic and metabolic CA and is lower in stroke, atherosclerosis, and with aging. Both LFO and VLFO synchronizations appear disturbed in stroke, while the former is also altered in internal carotid stenosis and hypertension. Conclusion: We conclude that amplitudes of LFOs and VLFOs are relatively robust measures for evaluating mechanisms of CA and synchronization analyses can show temporal disruption of CA. Further research and more coherent methodologies are needed.
Background and Purpose— Recent studies indicate a possible beneficial effect on neuroregeneration and vascular protection of selective serotonin reuptake inhibitors after stroke. We conducted a national multicentre study to explore these effects. Methods— The TALOS study (The Efficacy of Citalopram Treatment in Acute Stroke) is a Danish placebo-controlled, randomized, double-blind study of citalopram started within 7 days after symptom onset to detect improvement in functional outcomes and cardiovascular protection in nondepressed, first-ever ischemic stroke. Study medication was given as add-on to standard medical care and treatment duration and follow-up was 6 months. There were 2 coprimary outcomes: changes in functional disability from 1 to 6 months on the modified Rankin Scale, and a composite vascular end point of transient ischemic attack/stroke, myocardial infarction, or vascular mortality during the first 6 months. Results— We enrolled 642 patients randomized to either citalopram (n=319) or placebo (n=323). Median National Institutes of Health Stroke Scale was 5.3 (range, 0–27) versus 4.8 (range, 0–28) at admission. Improvement in functional recovery from 1 to 6 months occurred in 160 (50%) patients on citalopram and 136 (42%) on placebo (odds ratio, 1.27; 95% CI, 0.92–1.74; P =0.057). When dropouts before 31 days were excluded (n=90), the analysis population showed an odds ratio of 1.37 (95% CI, 0.97–1.91; P =0.07). During a median follow-up of 150 days, 23 (7%) patients in the citalopram group and 26 (8%) patients in the placebo group had a primary, vascular end point (hazard ratio, 0.89; 95% CI, 0.50–1.60; P =0.24). A total of 28 patients (4%) died (16 versus 12; P =0.42) during the study. Conclusions— Early citalopram treatment did not improve functional recovery in nondepressed ischemic stroke patients within the first 6 months, although a borderline statistical significant effect was observed in the analysis population. The risk of cardiovascular events was similar between treatment groups, and citalopram treatment was well tolerated. Clinical Trial Registration— URL: https://www.clinicaltrials.gov . Unique identifier: NCT01937182. URL: https://www.clinicaltrialsregister.eu/ . EudraCT number: 2013-002253-30.
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