Endogenous opioid peptides in parasympathetic, sympathetic and sensory nerves in the guinea-pig heart.

Research has suggested that exogenous opioid substances can have direct effects on cardiac muscle or influence neurotransmitter release via presynaptic modulation of neuronal inputs to the heart. In the present study, multiple-labelling immunohistochemistry was employed to determine the distribution of endogenous opioid peptides within the guinea-pig heart. Approximately 40% of cardiac ganglion cells contained immunoreactivity for dynorphin A (1-8), dynorphin A (1-17) and dynorphin B whilst 20% displayed leu-enkephalin immunoreactivity. Different populations of opioid-containing ganglion cells were identified according to the co-existence of opioid immunoreactivity with immunoreactivity for somatostatin and neuropeptide Y. Immunoreactivity for prodynorphin-derived peptides was observed in many sympathetic axons in the heart and was also observed, though to a lesser extent, in sensory axons. Leu-enkephalin immunoreactivity was observed in occasional sympathetic and sensory axons. No immunoreactivity was observed for met-enkephalin-arg-gly-leu or for beta-endorphin. These results demonstrate that prodynorphin-derived peptides are present in parasympathetic, sympathetic and sensory nerves within the heart, but suggest that only the prodynorphin gene is expressed in guinea-pig cardiac nerves. This study has shown that endogenous opioid peptides are well placed to regulate cardiac function via both autonomic and sensory pathways.

Differential contribution of mitochondria, NADPH oxidases, and glycolysis to region-specific oxidant stress in the anoxic-reoxygenated embryonic heart.

The ability of the developing myocardium to tolerate oxidative stress during early gestation is an important issue with regard to possible detrimental consequences for the fetus. In the embryonic heart, antioxidant defences are low, whereas glycolytic flux is high. The pro- and antioxidant mechanisms and their dependency on glucose metabolism remain to be explored. Isolated hearts of 4-day-old chick embryos were exposed to normoxia (30 min), anoxia (30 min), and hyperoxic reoxygenation (60 min). The time course of ROS production in the whole heart and in the atria, ventricle, and outflow tract was established using lucigenin-enhanced chemiluminescence. Cardiac rhythm, conduction, and arrhythmias were determined. The activity of superoxide dismutase, catalase, gutathione reductase, and glutathione peroxidase as well as the content of reduced and oxidized glutathione were measured. The relative contribution of the ROS-generating systems was assessed by inhibition of mitochondrial complexes I and III (rotenone and myxothiazol), NADPH oxidases (diphenylene iodonium and apocynine), and nitric oxide synthases (N-monomethyl-l-arginine and N-iminoethyl-l-ornithine). The effects of glycolysis inhibition (iodoacetate), glucose deprivation, glycogen depletion, and lactate accumulation were also investigated. In untreated hearts, ROS production peaked at 10.8 ± 3.3, 9 ± 0.8, and 4.8 ± 0.4 min (means ± SD; n = 4) of reoxygenation in the atria, ventricle, and outflow tract, respectively, and was associated with arrhythmias. Functional recovery was complete after 30-40 min. At reoxygenation, 1) the respiratory chain and NADPH oxidases were the main sources of ROS in the atria and outflow tract, respectively; 2) glucose deprivation decreased, whereas glycogen depletion increased, oxidative stress; 3) lactate worsened oxidant stress via NADPH oxidase activation; 4) glycolysis blockade enhanced ROS production; 5) no nitrosative stress was detectable; and 6) the glutathione redox cycle appeared to be a major antioxidant system. Thus, the glycolytic pathway plays a predominant role in reoxygenation-induced oxidative stress during early cardiogenesis. The relative contribution of mitochondria and extramitochondrial systems to ROS generation varies from one region to another and throughout reoxygenation.

Sleep EEG changes after middle cerebral artery infarcts in mice: different effects of striatal and cortical lesions.

STUDY OBJECTIVES: Hemispheric stroke in humans is associated with sleep-wake disturbances and sleep electroencephalogram (EEG) changes. The correlation between these changes and stroke extent remains unclear. In the absence of experimental data, we assessed sleep EEG changes after focal cerebral ischemia of different extensions in mice. DESIGN: Following electrode implantation and baseline sleep-wake EEG recordings, mice were submitted to sham surgery (control group), 30 minutes of intraluminal middle cerebral artery (MCA) occlusion (striatal stroke), or distal MCA electrocoagulation (cortical stroke). One and 12 days after stroke, sleep-wake EEG recordings were repeated. The EEG recorded from the healthy hemisphere was analyzed visually and automatically (fast Fourier analysis) according to established criteria. MEASUREMENTS AND RESULTS: Striatal stroke induced an increase in non-rapid eye movement (NREM) sleep and a reduction of rapid eye movement sleep. These changes were detectable both during the light and the dark phase at day 1 and persisted until day 12 after stroke. Cortical stroke induced a less-marked increase in NREM sleep, which was present only at day 1 and during the dark phase. In cortical stroke, the increase in NREM sleep was associated in the wake EEG power spectra, with an increase in the theta and a reduction in the beta activity. CONCLUSION: Cortical and striatal stroke lead to different sleep-wake EEG changes in mice, which probably reflect variable effects on sleep-promoting and wakefulness-maintaining neuronal networks.

mitoKATP channel activation in the postanoxic developing heart protects E-C coupling via NO-, ROS-, and PKC-dependent pathways.

Whereas previous studies have shown that opening of the mitochondrial ATP-sensitive K(+) (mitoK(ATP)) channel protects the adult heart against ischemia-reperfusion injury, it remains to be established whether this mechanism also operates in the developing heart. Isolated spontaneously beating hearts from 4-day-old chick embryos were subjected to 30 min of anoxia followed by 60 min of reoxygenation. The chrono-, dromo-, and inotropic disturbances, as well as alterations of the electromechanical delay (EMD), reflecting excitation-contraction (E-C) coupling, were investigated. Production of reactive oxygen species (ROS) in the ventricle was determined using the intracellular fluorescent probe 2',7'-dichlorofluorescin (DCFH). Effects of the specific mitoK(ATP) channel opener diazoxide (Diazo, 50 microM) or the blocker 5-hydroxydecanoate (5-HD, 500 microM), the nitric oxide synthase (NOS) inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME, 50 microM), the antioxidant N-(2-mercaptopropionyl)glycine (MPG, 1 mM), and the PKC inhibitor chelerythrine (Chel, 5 microM) on oxidative stress and postanoxic functional recovery were determined. Under normoxia, the baseline parameters were not altered by any of these pharmacological agents, alone or in combination. During the first 20 min of postanoxic reoxygenation, Diazo doubled the peak of ROS production and, interestingly, accelerated recovery of ventricular EMD and the PR interval. Diazo-induced ROS production was suppressed by 5-HD, MPG, or L-NAME, but not by Chel. Protection of ventricular EMD by Diazo was abolished by 5-HD, MPG, L-NAME, or Chel, whereas protection of the PR interval was abolished by L-NAME exclusively. Thus pharmacological opening of the mitoK(ATP) channel selectively improves postanoxic recovery of cell-to-cell communication and ventricular E-C coupling. Although the NO-, ROS-, and PKC-dependent pathways also seem to be involved in this cardioprotection, their interrelation in the developing heart can differ markedly from that in the adult myocardium.

Comparison of application of the ACC/AHA guidelines, Adult Treatment Panel III guidelines, and European Society of Cardiology guidelines for cardiovascular disease prevention in a European cohort.

IMPORTANCE: The 2013 American College of Cardiology/American Heart Association (ACC/AHA) guidelines introduced a prediction model and lowered the threshold for treatment with statins to a 7.5% 10-year hard atherosclerotic cardiovascular disease (ASCVD) risk. Implications of the new guideline's threshold and model have not been addressed in non-US populations or compared with previous guidelines. OBJECTIVE: To determine population-wide implications of the ACC/AHA, the Adult Treatment Panel III (ATP-III), and the European Society of Cardiology (ESC) guidelines using a cohort of Dutch individuals aged 55 years or older. DESIGN, SETTING, AND PARTICIPANTS: We included 4854 Rotterdam Study participants recruited in 1997-2001. We calculated 10-year risks for "hard" ASCVD events (including fatal and nonfatal coronary heart disease [CHD] and stroke) (ACC/AHA), hard CHD events (fatal and nonfatal myocardial infarction, CHD mortality) (ATP-III), and atherosclerotic CVD mortality (ESC). MAIN OUTCOMES AND MEASURES: Events were assessed until January 1, 2012. Per guideline, we calculated proportions of individuals for whom statins would be recommended and determined calibration and discrimination of risk models. RESULTS: The mean age was 65.5 (SD, 5.2) years. Statins would be recommended for 96.4% (95% CI, 95.4%-97.1%; n = 1825) of men and 65.8% (95% CI, 63.8%-67.7%; n = 1523) of women by the ACC/AHA, 52.0% (95% CI, 49.8%-54.3%; n = 985) of men and 35.5% (95% CI, 33.5%-37.5%; n = 821) of women by the ATP-III, and 66.1% (95% CI, 64.0%-68.3%; n = 1253) of men and 39.1% (95% CI, 37.1%-41.2%; n = 906) of women by ESC guidelines. With the ACC/AHA model, average predicted risk vs observed cumulative incidence of hard ASCVD events was 21.5% (95% CI, 20.9%-22.1%) vs 12.7% (95% CI, 11.1%-14.5%) for men (192 events) and 11.6% (95% CI, 11.2%-12.0%) vs 7.9% (95% CI, 6.7%-9.2%) for women (151 events). Similar overestimation occurred with the ATP-III model (98 events in men and 62 events in women) and ESC model (50 events in men and 37 events in women). The C statistic was 0.67 (95% CI, 0.63-0.71) in men and 0.68 (95% CI, 0.64-0.73) in women for hard ASCVD (ACC/AHA), 0.67 (95% CI, 0.62-0.72) in men and 0.69 (95% CI, 0.63-0.75) in women for hard CHD (ATP-III), and 0.76 (95% CI, 0.70-0.82) in men and 0.77 (95% CI, 0.71-0.83) in women for CVD mortality (ESC). CONCLUSIONS AND RELEVANCE: In this European population aged 55 years or older, proportions of individuals eligible for statins differed substantially among the guidelines. The ACC/AHA guideline would recommend statins for nearly all men and two-thirds of women, proportions exceeding those with the ATP-III or ESC guidelines. All 3 risk models provided poor calibration and moderate to good discrimination. Improving risk predictions and setting appropriate population-wide thresholds are necessary to facilitate better clinical decision making.

Calcium, vitamin D and cardiovascular disease.

The relationship between calcium and cardiovascular diseases (CVD) has been explored for a long time. Studies exploring the effect of calcium intake or calcium supplementation on cardiovascular risk suggest that systolic blood pressure increases under low calcium intake and decreases with calcium supplementation. A lower calcium intake has been associated with an increased risk of stroke. However, the impact of calcium supplementation on stroke risk remains unclear. Calcium supplementation may increase the risk of myocardial infarction. The relationship between vitamin D and CVD has been explored more recently. Negative correlations between vitamin D levels and the risk of hypertension, myocardial infarction, and stroke have been reported in several observational studies. The effect of vitamin D supplementation on blood pressure is still unclear and no effect of vitamin D supplementation on coronary heart disease or stroke has been clearly demonstrated. There is a lack of randomized clinical trials primarily addressing the effect of these parameters on CVD. Therefore, the real impact of calcium and vitamin D on cardiovascular outcomes remains to be documented by appropriate experimental data.

Recanalization and Collaterals Predict Outcome in Proximal MCA Occlusion, but neither Penumbra nor Core of Stroke

Data on new predictors of outcome include penumbra core or collaterals.Objective: To test the predictive value of recanalization, collaterals, penumbra and core of ischemia for functional outcome in a large group of patients with MCA occlusion. Method: Consecutive events included prospectively in the Acute Stroke Registry and Analysis of Lausanne from April 2002 to April 2009 with an acute stroke due to proximal MCA occlusion (M1) were considered for analysis. Acute CTA were reviewed to grade the collaterals (dichotomized in poor __50% or good _50% compared to the normal side) and localization of M1 occlusion (proximal or mid-distal). Acute CTP were reviewed and reconstructed to determine penumbra, core and stroke index (penumbra/penumbra_core) of brain ischemia. Good outcome was defined by mRS 0-2 at 3 months.Results: Among 242 events (115 male, mean NIHSS 18.1, SD 5.8, mean age 66, SD 15), 42% were treated with intravenous thrombolysis, and 3% with intraarterial thrombolysis. Collateral status was rated as poor in 53% of events and proximal M1 occlusion was present in 64%. Recanalization determined at 24 hours with CTA was complete in 26% events and partial/absent in 54%.CTP was available for 212 events. Mean penumbra was 88.6 cm3 (median 84.4, SD 53.8), mean core was 54.1 cm3 (median 46.2, SD 45.7) and stroke index was 64% (median 68%, SD 25%). Good outcome was observed in 87 events (36%) and was associated in multivariate logistic regression with thrombolysis (p_0.02, OR_2.5, 95% CI 1.2-5.4), recanalization (p_0.001, OR_4.1, 95% CI 1.9-8.9), lower NIHSS (p_0.001, OR_0.84, 95% CI 0.78-0.91), male gender (p_0.01, OR_2.8, 95% CI 1.3-5.9), mRS prior to stroke (p_0.02, OR_0.5, 95% CI 0.28-0.9) and good collateral status (p_0.005, OR_3, 95% CI 1.4-6.4). Nor penumbra, nor core, nor stroke index were significant in the multivariate model, even if an association was present in the univariate model between good functional outcome and penumbra (p_0.004, OR_1.008, 95% CI 1.003-1.01), core (p_0.001, OR_0.98, 95% CI 0.976-0.99) and strokeindex (p_0.001, OR_16.7, 95% CI 4.6 59.9).Conclusion: MCA recanalization is the best predictor for good functional outcome, followed by collateral status. CTP data did not predict the functional outcome in our large group of M1 occlusion. Author Disclosures: C. Odier: None. P. Michel: Research Grant; Significant; Paion, Lundbeck. Speakers; Modest; Boehringer-Ingelheim. Consultant/Advisory Board; Modest; Boehringer- Ingelheim. Consultant/Advisory Board; Significant; Servier, Lundbeck.

Discrepancies between office and ambulatory blood pressure: clinical implications.

BACKGROUND: Recent trials have documented no benefit from small reductions in blood pressure measured in the clinical office. However, ambulatory blood pressure is a better predictor of cardiovascular events than office-based blood pressure. We assessed control of ambulatory blood pressure in treated hypertensive patients at high cardiovascular risk. METHODS: We selected 4729 patients from the Spanish Ambulatory Blood Pressure Monitoring Registry. Patients were aged >/=55 years and presented with at least one of the following co-morbidities: coronary heart disease, stroke, and diabetes with end-organ damage. An average of 2 measures of blood pressure in the office was used for analyses. Also, 24-hour ambulatory blood pressure was recorded at 20-minute intervals with a SpaceLabs 90207 device. RESULTS: Patients had a mean age of 69.6 (+/-8.2) years, and 60.8% of them were male. Average time from the diagnosis of hypertension to recruitment into the Registry was 10.9 (+/-8.4) years. Mean blood pressure in the office was 152.3/82.3 mm Hg, and mean 24-hour ambulatory blood pressure was 133.3/72.4 mm Hg. About 60% of patients with an office-pressure of 130-139/85-89 mm Hg, 42.4% with office-pressure of 140-159/90-99 mm Hg, and 23.3% with office-pressure > or =160/100 mm Hg were actually normotensive, according to 24-hour ambulatory blood pressure criteria (<130/80 mm Hg). CONCLUSION: We suggest that the lack of benefit of antihypertensive therapy in some trials may partly be due to some patients having normal pressure at trial baseline. Ambulatory monitoring of blood pressure may allow for a better assessment of trial eligibility.

Intravenous insulin treatment in acute stroke: a systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: Poststroke hyperglycemia has been associated with unfavorable outcome. Several trials investigated the use of intravenous insulin to control hyperglycemia in acute stroke. This meta-analysis summarizes all available evidence from randomized controlled trials in order to assess its efficacy and safety. METHODS: We searched PubMed until 15/02/2013 for randomized clinical trials using the following search items: 'intravenous insulin' or 'hyperglycemia', and 'stroke'. Eligible studies had to be randomized controlled trials of intravenous insulin in hyperglycemic patients with acute stroke. Analysis was performed on intention-to-treat basis using the Peto fixed-effects method. The efficacy outcomes were mortality and favorable functional outcome. The safety outcomes were mortality, any hypoglycemia (symptomatic or asymptomatic), and symptomatic hypoglycemia. RESULTS: Among 462 potentially eligible articles, nine studies with 1491 patients were included in the meta-analysis. There was no statistically significant difference in mortality between patients who were treated with intravenous insulin and controls (odds ratio: 1.16, 95% confidence interval: 0.89-1.49). Similarly, the rate of favorable functional outcome was not statistically different (odds ratio: 1.01, 95% confidence interval: 0.81-1.26). The rates of any hypoglycemia (odds ratio: 8.19, 95% confidence interval: 5.60-11.98) and of symptomatic hypoglycemia (odds ratio: 6.15, 95% confidence interval: 1.88-20.15) were higher in patients treated with intravenous insulin. There was no heterogeneity across the included trials in any of the outcomes studied. CONCLUSIONS: This meta-analysis of randomized controlled trials does not support the use of intravenous insulin in hyperglycemic stroke patients to improve mortality or functional outcome. The risk of hypoglycemia is increased, however.

Stroke initial severity and outcome relative to insurance status in a universal health care system in Switzerland.

BACKGROUND:  Socioeconomic status is thought to have a significant influence on stroke incidence, risk factors and outcome. Its influence on acute stroke severity, stroke mechanisms, and acute recanalisation treatment is less known. METHODS:  Over a 4-year period, all ischaemic stroke patients admitted within 24 h were entered prospectively in a stroke registry. Data included insurance status, demographics, risk factors, time to hospital arrival, initial stroke severity (NIHSS), etiology, use of acute treatments, short-term outcome (modified Rankin Scale, mRS). Private insured patients (PI) were compared with basic insured patients (BI). RESULTS:  Of 1062 consecutive acute ischaemic stroke patients, 203 had PI and 859 had BI. They were 585 men and 477 women. Both populations were similar in age, cardiovascular risk factors and preventive medications. The onset to admission time, thrombolysis rate, and stroke etiology according to TOAST classification were not different between PI and BI. Mean NIHSS at admission was significantly higher for BI. Good outcome (mRS ≤ 2) at 7 days and 3 months was more frequent in PI than in BI. CONCLUSION:  We found better outcome and lesser stroke severity on admission in patients with higher socioeconomic status in an acute stroke population. The reason for milder strokes in patients with better socioeconomic status in a universal health care system needs to be explained.

HACEK infective endocarditis: characteristics and outcomes from a large, multi-national cohort.

The HACEK organisms (Haemophilus species, Aggregatibacter species, Cardiobacterium hominis, Eikenella corrodens, and Kingella species) are rare causes of infective endocarditis (IE). The objective of this study is to describe the clinical characteristics and outcomes of patients with HACEK endocarditis (HE) in a large multi-national cohort. Patients hospitalized with definite or possible infective endocarditis by the International Collaboration on Endocarditis Prospective Cohort Study in 64 hospitals from 28 countries were included and characteristics of HE patients compared with IE due to other pathogens. Of 5591 patients enrolled, 77 (1.4%) had HE. HE was associated with a younger age (47 vs. 61 years; p<0.001), a higher prevalence of immunologic/vascular manifestations (32% vs. 20%; p<0.008) and stroke (25% vs. 17% p = 0.05) but a lower prevalence of congestive heart failure (15% vs. 30%; p = 0.004), death in-hospital (4% vs. 18%; p = 0.001) or after 1 year follow-up (6% vs. 20%; p = 0.01) than IE due to other pathogens (n = 5514). On multivariable analysis, stroke was associated with mitral valve vegetations (OR 3.60; CI 1.34-9.65; p<0.01) and younger age (OR 0.62; CI 0.49-0.90; p<0.01). The overall outcome of HE was excellent with the in-hospital mortality (4%) significantly better than for non-HE (18%; p<0.001). Prosthetic valve endocarditis was more common in HE (35%) than non-HE (24%). The outcome of prosthetic valve and native valve HE was excellent whether treated medically or with surgery. Current treatment is very successful for the management of both native valve prosthetic valve HE but further studies are needed to determine why HE has a predilection for younger people and to cause stroke. The small number of patients and observational design limit inferences on treatment strategies. Self selection of study sites limits epidemiological inferences.

GLUT8 is dispensable for embryonic development but influences hippocampal neurogenesis and heart function.

GLUT8 is a glucose transporter isoform expressed at high levels in testis; at intermediate levels in the brain, including the hippocampus; and at lower levels in the heart and several other tissues. GLUT8 is located in an intracellular compartment and does not appear to translocate to the cell surface, except in blastocysts, where insulin has been reported to induce its surface expression. Here, we generated mice with inactivation of the glut8 gene. We showed that expression of GLUT8 was not required for normal embryonic development and that glut8-/- mice had normal postnatal development, glucose homeostasis, and response to mild stress. Adult glut8-/- mice showed increased proliferation of hippocampal cells but no defect in memory acquisition and retention. Absence of GLUT8 from the heart did not alter heart size and morphology but led to an increase in P-wave duration, which was not associated with abnormal Nav1.5 Na+ channel or connexin expression. Thus, absence of GLUT8 expression in the mouse caused complex but mild physiological alterations.

Ventricular but not atrial electro-mechanical delay of the embryonic heart is altered by anoxia-reoxygenation and improved by nitric oxide.

BACKGROUND/AIM: Excitation-contraction coupling is modulated by nitric oxide (NO) which otherwise has either beneficial or detrimental effects on myocardial function during hypoxia-reoxygenation. This work aimed at characterizing the variations of electromechanical delay (EMD) induced by anoxia-reoxygenation within the developing heart and determining whether atrial and ventricular EMD are modulated by NO to the same extent. METHODS: Hearts of 4 or 4.5-day-old chick embryos were excised and submitted in vitro to normoxia (45 min), anoxia (30 min) and reoxygenation (60 min). Electrocardiogram and atrial and ventricular contractions were simultaneously recorded throughout experiment. Anoxia-reoxygenation-induced chrono-, dromo-and inotropic disturbances and changes in EMD in atrium (EMDa) and ventricle (EMDv) were investigated in control hearts and in hearts exposed to 0.1, 1, 10, 50 and 100 microM of DETA-NONOate (a NO donating agent) or to 50 microM of L-NAME (a NOS inhibitor). RESULTS: Under normoxia, heart rate, PR interval, ventricular shortening velocity, EMDa and EMDv were similar in control, L-NAME-treated and DETA-NONOate-treated hearts. Under anoxia, cardiac activity became markedly erratic within less than 10 min in all groups. At the onset of reoxygenation, EMDv was increased by about 300% with respect to the preanoxic value while EMDa did not vary significatively. Compared to control conditions, L-NAME or DETA-NONOate had no influence on the negative chrono-, dromo- and inotropic effects induced by anoxia-reoxygenation. However, L-NAME prolonged EMDv during anoxia and delayed EMDv recovery during reoxygenation while 100 microM DETA-NONOate had the opposite effects. EMDa was neither affected by NOS inhibitor nor NO donor. At the end of reoxygenation, all the investigated parameters returned to their basal values. CONCLUSION: This work provides evidence that a NO-dependent pathway is involved in regulation of the ventricular excitation-contraction coupling in the anoxic-reoxygenated developing heart.

Three-dimensional ordered-subset expectation maximization iterative protocol for evaluation of left ventricular volumes and function by quantitative gated SPECT: a dynamic phantom study.

The purposes of this study were to characterize the performance of a 3-dimensional (3D) ordered-subset expectation maximization (OSEM) algorithm in the quantification of left ventricular (LV) function with (99m)Tc-labeled agent gated SPECT (G-SPECT), the QGS program, and a beating-heart phantom and to optimize the reconstruction parameters for clinical applications. METHODS: A G-SPECT image of a dynamic heart phantom simulating the beating left ventricle was acquired. The exact volumes of the phantom were known and were as follows: end-diastolic volume (EDV) of 112 mL, end-systolic volume (ESV) of 37 mL, and stroke volume (SV) of 75 mL; these volumes produced an LV ejection fraction (LVEF) of 67%. Tomographic reconstructions were obtained after 10-20 iterations (I) with 4, 8, and 16 subsets (S) at full width at half maximum (FWHM) gaussian postprocessing filter cutoff values of 8-15 mm. The QGS program was used for quantitative measurements. RESULTS: Measured values ranged from 72 to 92 mL for EDV, from 18 to 32 mL for ESV, and from 54 to 63 mL for SV, and the calculated LVEF ranged from 65% to 76%. Overall, the combination of 10 I, 8 S, and a cutoff filter value of 10 mm produced the most accurate results. The plot of the measures with respect to the expectation maximization-equivalent iterations (I x S product) revealed a bell-shaped curve for the LV volumes and a reverse distribution for the LVEF, with the best results in the intermediate range. In particular, FWHM cutoff values exceeding 10 mm affected the estimation of the LV volumes. CONCLUSION: The QGS program is able to correctly calculate the LVEF when used in association with an optimized 3D OSEM algorithm (8 S, 10 I, and FWHM of 10 mm) but underestimates the LV volumes. However, various combinations of technical parameters, including a limited range of I and S (80-160 expectation maximization-equivalent iterations) and low cutoff values (< or =10 mm) for the gaussian postprocessing filter, produced results with similar accuracies and without clinically relevant differences in the LV volumes and the estimated LVEF.

Frequency and determinants of using pharmacological enhancement in the clinical practice of in-hospital stroke rehabilitation.

Background: Pharmacological enhancement in stroke rehabilitation (PESR) is promising. Data about its use in clinical practice are missing. Methods: In a prospective, explorative study of four rehabilitation centers, we systematically observed the frequency and determinants of using PESR in consecutive patients. PESR was defined as using agents potentially enhancing post-stroke recovery exclusively to aid rehabilitation without an established indication. Results: 257 (55.4%) of 464 patients had agents potentially enhancing recovery. Selective serotonin reuptake inhibitors (SSRI) (n = 125, 26.9%), levodopa (n = 114, 24.6%), serotonin-noradrenaline reuptake inhibitors (SNRI) (n = 52, 11.2%), and acetylcholinesterase inhibitors (n = 48, 10.3%) were used most often. SSRI in 102/125 patients and SNRI in 46/52 patients were mostly used for accompanying depressive symptoms. 159 (34.3%) patients had PESR (without an otherwise established indication). In PESR patients, levodopa (n = 102, 64.1%) was used most commonly. PESR was primarily used for aphasia (36.5%) and paresis (25.2%). PESR patients did not differ from non-PESR patients in age, gender and stroke type. However, the utilization rates of PESR differed significantly across centers (2, 4, 38 and 55%). Conclusion: SSRI and SNRI were predominately used for accompanying depression, while levodopa was nearly exclusively used to aid stroke rehabilitation in the absence of an otherwise established indication. The differences in utilization rates for PESR between centers suggest therapeutic uncertainty and indicate the need for additional studies.