Systolic myocardial dysfunction in patients with type 2 diabetes mellitus: identification at MR imaging with cine displacement encoding with stimulated echoes

PURPOSE

To determine if cine displacement encoding with stimulated echoes (DENSE) can help to identify and determine the patterns of subclinical myocardial systolic dysfunction in patients with type 2 diabetes mellitus (DM) when compared with cine DENSE in control patients.

MATERIALS AND METHODS

After obtaining approval from the institutional ethics committee and written informed consent from the patients, 37 patients with type 2 DM without overt heart disease and 23 age-matched control patients were prospectively included in the study. The patients underwent standard cine magnetic resonance (MR) imaging with two-dimensional cine DENSE acquisitions. Circumferential (Ecc) and radial (Err) systolic strains were measured on short-axis views at basal, mid, and apical left ventricular levels. Longitudinal strain (Ell) was measured on four- and two-chamber views. Statistical testing included the intraclass correlation coefficient and multiple linear regression analysis.

RESULTS

The intraobserver intraclass correlation coefficient values were 0.85, 0.95, and 0.90, and the interobserver intraclass correlation coefficient values were 0.79, 0.91 and 0.80 for Ecc, Err, and Ell, respectively. The left ventricular ejection fraction was in the reference range and similar between the groups, and the patients with DM showed a decrease in Ecc (-14.4%±1.6 vs -17.0%±1.6, P<.001), Err (36.2%±10.9 vs 44.4%±9.9, P=.006) and Ell (-12.9%±2.1 vs -15.5%±1.6, P<.001) compared with the control patients. Finally, DM was independently associated with Ecc (P<.001), Err (P=.05) and Ell (P=.01) after adjustment for age, sex, hypertension, body mass index, and left ventricular mass.

CONCLUSION

Cine DENSE, a motion-encoding MR imaging technique for myocardial strain assessment with high spatial resolution, appears to be useful in the identification of subclinical myocardial dysfunction in patients with DM.

Diastolic dysfunction in patients with type 2 diabetes mellitus: is it really the first marker of diabetic cardiomyopathy?

BACKGROUND

Diastolic dysfunction is considered the first marker of diabetic cardiomyopathy. However, preclinical systolic alteration was also recently described by strain, but its association with diastolic dysfunction has never been investigated.

METHODS

One hundred fourteen patients with type 2 diabetes mellitus (DM) with controlled blood pressure and without overt heart disease were prospectively enrolled and compared with 88 age-matched controls. All subjects underwent comprehensive echocardiography, including diastolic evaluation according to current recommendations and speckle-tracking imaging. The prevalence of diastolic dysfunction, the determinants of diastolic parameters, and the association between preclinical systolic and diastolic dysfunctions were studied.

RESULTS

Diastolic parameters were altered in patients compared with controls, with lower E/A ratios, longer mitral deceleration and isovolumic relaxation times, and higher E/e' ratio. Diastolic dysfunction occurred in 47% of patients with DM (33% and 14% with grade I and II diastolic dysfunction, respectively) and systolic alteration (longitudinal strain ≥ -18%) in 32% of patients. Whereas longitudinal systolic strain was independently associated with DM and gender, diastolic parameters were influenced by many factors, including age, rate-pressure product, history of hypertension, and body mass index. Systolic alteration occurred in 28% of patients with DM with normal diastolic function and in 35% with diastolic dysfunction.

CONCLUSIONS

Diastolic dysfunction diagnosed according to current recommendations is frequent in patients with DM but is also influenced by other factors. Systolic strain alteration may exist despite normal diastolic function, indicating that diastolic dysfunction should not be considered the first marker of a preclinical form of diabetic cardiomyopathy.

Validation of noninvasive measurements of cardiac output in mice using echocardiography

BACKGROUND

Although multiple echocardiographic methods exist to calculate cardiac output (CO), they have not been validated in mice using a reference method.

METHODS

Echocardiographic and flow probe measurements of CO were obtained in mice before and after albumin infusion and inferior vena cava occlusions. Echocardiography was also performed before and after endotoxin injection. Cardiac output was calculated using left ventricular volumes obtained from an M-mode or a two-dimensional view, left ventricular stroke volume calculated using the pulmonary flow, or estimated by the measurement of pulmonary velocity time integral (VTI).

RESULTS

Close correlations were demonstrated between flow probe-measured CO and all echocardiographic measurements of CO. All echocardiographic-derived CO overestimated the flow probe-measured CO. Two-dimensional image-derived CO was associated with the smallest overestimation of CO. Interobserver variability was lowest for pulmonary VTI-derived CO.

CONCLUSION

In mice, CO calculated from two-dimensional parasternal long-axis images is most accurate when compared with flow probe measurements; however, pulmonary VTI-derived CO is subject to less variability.

[Why and how to use the new body mass index curves for children]

Body mass index (BMI) curves are very useful tools to supervise corpulence during growth and to detect children at risk of overweight and obesity early. In 2009, the French National Nutrition Health Program decided to update the BMI curves used in France. A working group was then created, coordinated by the committee on nutrition of the société française de pédiatrie and by the association pour la prevention de l'obésité en pédiatrie. This article discusses the criteria adopted in elaborating the new curves among the existing references and curves (French references, the International Obesity Task Force [IOTF], the World Health Organization [WHO] standards). It presents recommendations for using the new curves and the BMI values used to define weight insufficiency, overweight, and obesity according to the references utilized.

[Morning snack offer in kindergarten: outlook and practices in Aquitaine, France, between 2004 and 2008]

The Nutrition, Prevention and Health for Children and Teenagers in Aquitaine program is a regional implementation of the French National Program of Nutrition and Health (PNNS). The first of two surveys of a representative sample of Aquitaine preschools was conducted in 2004-2005. This survey showed that more than 2/3 of teachers offered a morning snack to their pupils at around 10 o'clock in the morning, mainly composed of sweet cakes, cookies, or candies. Following this initial survey, actions were implemented starting in September 2005, aiming to stop systematic morning snacks or improve their composition. The same survey was repeated during 2007-2008 in order to analyze the changes in morning snack practices in preschools between 2004-2005 and 2007-2008. Data were collected from teachers of Aquitaine's preschools who filled out questionnaires. Schools were randomly chosen according to their size and whether or not they belonged to a priority education zone (ZEP). The results show that 57.9% of teachers organized a morning snack in 2007-2008, versus 68.7% in 2004-2005. In 2004-2005, 22% of teachers considered the morning snack as "unjustified" compared to 44% in 2007-2008. The composition of morning snacks improved: 17.7% of teachers offered fruit and/or milk in 2007-2008 versus 8.5% in 2004-2005. Morning snacks composed of other foods (such as sweets, chocolate pieces, cookies, pastries, bread, fruit juice) decreased from 60.2% in 2004-2005 to 40.2% in 2007-2008. In 2007-2008, 19% of the teachers reported that children had snacks in their schoolbag versus 34% in 2004-2005. The proportion of teachers reporting children having snacks in their schoolbag decreased from 34% in 2004-2005 to 19% in 2007-2008. Comparison between these two surveys is encouraging as it shows an improvement of the perception and practices of teachers regarding morning snacks. These results encourage the partners of this program to continue the fieldwork actions.

[Early screening criteria for children at risk of overweight]

BACKGROUND

Health professionals who monitor the growth of children are also involved in the early detection of overweight. Appropriate tools are required for this purpose.

OBJECTIVE

The study sought to identify predictive markers of the development of subsequent overweight using a simple set of criteria.

METHODS

A consecutive cohort was composed of 1424 grade 4 children in Aquitaine, France, aged 8-9 years. Body mass index (BMI) was calculated during school health assessments at 8-9 years of age. Data from previous assessments at 3-4 and 5-6 years of age were also collected.

RESULTS

Of the 189/1424 children (13.9 %) who were overweight according to the French national cut off for children aged 8-9 years, 67 (33.8 %) were already overweight at 3-4 years and 107 (54.1 %) at 5-6 years. Of the 134 (9.4 %) who were overweight at 5-6 years, 43.3 % were already overweight at 3-4 years and 79.9 % were overweight at 8-9 years. On the other hand, 76 of these 134 children (56.7 %) were not overweight at 3-4 years, so they had become overweight between the two assessments. The combination of the criterion "overweight at 3-4 years or 5-6 years" and "increase in BMI>1kg/m(2) between 3-4 years and 5-6 years" appears to be the best predictor of the risk of overweight at 8-9 years, with good sensitivity (75.3 %) and specificity (87.9 %).

CONCLUSION

A predictive tool based on BMI changes between ages 3-4 years and 5-6 years could be used for the early detection of the risk of developing overweight and obesity. The tool is easy to use, especially for health care in schools. Furthermore, the present findings confirm the value of following up and managing children who are already overweight between the ages of 3 and 6 years.

Developing collaborative person-centred practice: A pilot project on a palliative care unit

Maximizing interprofessional collaborative patient-centred practice holds promise for improving patient care and creating satisfying work roles. In Canada's evolving health care system, there are demands for increased efficiency, cost-effectiveness, and quality improvement. Interprofessional collaboration warrants re-examination because maximizing interprofessional collaboration, especially nurse-physician collaboration, holds promise for improving patient care and creating satisfying work roles. A palliative care team seized the opportunity to pilot a different approach to patient and family care when faced with a reduction in medical staff. Grounded in a collaborative patient-centred practice approach, the Canadian Hospice Palliative Care Association's National Model to Guide Hospice Palliative Care (2002), and outcomes from program retreats and workgroups, a collaborative person-centred model of care was developed for a 12-bed pilot project. Preliminary findings show that the pilot project team perceived some specific benefits in continuity of care and interprofessional collaboration, while the presence of the physician was reduced to an average of 3.82 hours on the pilot wing, compared with 8 hours on the non-pilot wings. This pilot study suggests that a person-centred model, when focused on the physician-nurse dyad, may offer improved efficiency, job satisfaction and continuity of care on a palliative care unit. Incorporating all team members and developing strategies to successfully expand the model across the whole unit are the next challenges. Further research into the impact of these changes on the health care professionals, management and patients and families is essential.

Myocardial alterations in senescent mice and effect of exercise training: a strain rate imaging study

BACKGROUND

Aging is accompanied by an alteration in myocardial contractility. However, its noninvasive detection is difficult. The effect of chronic exercise on this decrease is unknown. Murine models of senescence are increasingly used to test therapies in aging. We tested whether strain rate imaging detected left ventricular (LV) systolic dysfunction in aging mice and was able to assess a potential improvement after exercise.

METHODS AND RESULTS

Young (3 weeks), adult (2 to 3 months), and old (6 to 18 months) C57BL6 male mice underwent echocardiograms with strain rate imaging, either in sedentary conditions or before, 2 weeks and 4 weeks after chronic swimming. Hemodynamic parameters of LV function including maximal and end-systolic elastance were obtained before euthanizing. LV fibrosis was measured using Sirius red staining. Conventional echocardiography was unable to detect LV systolic dysfunction in old mice, whereas both systolic strain rate and load-independent hemodynamic parameters such as preload recruitable stroke work and end-systolic elastance were significantly decreased. Both strain rate and load-independent hemodynamic parameters normalized after 4 weeks of exercise. Both endocardial and epicardial fibrosis were increased in the LV of aging mice. Endocardial fibrosis decreased in exercised aged mice.

CONCLUSIONS

Strain rate noninvasively detects LV systolic dysfunction associated with aging in mice, whereas conventional echocardiography does not. Chronic exercise normalizes LV systolic function and decreases fibrosis in old mice. Strain rate imaging in mice may be a useful tool to monitor the effect of new therapeutic strategies preventing the myocardial dysfunction associated with aging.

Effect of cyclosporine on reperfusion injury in acute myocardial infarction

BACKGROUND

Experimental evidence suggests that cyclosporine, which inhibits the opening of mitochondrial permeability-transition pores, attenuates lethal myocardial injury that occurs at the time of reperfusion. In this pilot trial, we sought to determine whether the administration of cyclosporine at the time of percutaneous coronary intervention (PCI) would limit the size of the infarct during acute myocardial infarction.

METHODS

We randomly assigned 58 patients who presented with acute ST-elevation myocardial infarction to receive either an intravenous bolus of 2.5 mg of cyclosporine per kilogram of body weight (cyclosporine group) or normal saline (control group) immediately before undergoing PCI. Infarct size was assessed in all patients by measuring the release of creatine kinase and troponin I and in a subgroup of 27 patients by performing magnetic resonance imaging (MRI) on day 5 after infarction.

RESULTS

The cyclosporine and control groups were similar with respect to ischemia time, the size of the area at risk, and the ejection fraction before PCI. The release of creatine kinase was significantly reduced in the cyclosporine group as compared with the control group (P=0.04). The release of troponin I was not significantly reduced (P=0.15). On day 5, the absolute mass of the area of hyperenhancement (i.e., infarcted tissue) on MRI was significantly reduced in the cyclosporine group as compared with the control group, with a median of 37 g (interquartile range, 21 to 51) versus 46 g (interquartile range, 20 to 65; P=0.04). No adverse effects of cyclosporine administration were detected.

CONCLUSIONS

In our small, pilot trial, administration of cyclosporine at the time of reperfusion was associated with a smaller infarct by some measures than that seen with placebo. These data are preliminary and require confirmation in a larger clinical trial.

Assessment of myocardial ischemia and viability using tissue Doppler and deformation imaging: the lessons from the experimental studies

Tissue Doppler imaging and strain rate imaging are quantitative methods for assessing myocardial function and have been shown to overcome the limitations of current ultrasound methods in assessing the complex changes in regional myocardial function that occur in differing ischemic substrates. Tissue Doppler imaging (TDI) measures in real time the myocardial velocity gradient which is an index of myocardial deformation. Strain and strain rate (SR) imaging has been shown to be a sensitive technique for quantifying regional myocardial deformation. Strain rate is less load-dependent that strain and provides therefore a better measure of contractility. In the setting of ischemia, experimental studies have shown that strain imaging was an accurate method for quantitative evaluation of regional myocardial function and may yield important physiological data. In myocardial infarction, transmural extension of scar distribution in the infarct zone is proportionally related to the reduction in systolic function measured by the radial transmural velocity gradient or by strain rate imaging. Measurement of both systolic and post-systolic deformation both at rest and during a graded dobutamine infusion may help to distinguish between transmural and non transmural infarcts. In conclusion, strain imaging has the ability to evaluate of regional myocardial function. Strain rate has not replaced conventional grey-scale imaging in the assessment of regional left ventricular function and the implement of these new indices in the routine clinical practice will need additional clinical and large-scale studies.

Anthropometric and behavioral patterns associated with weight maintenance after an obesity treatment in adolescents

OBJECTIVE

To identify anthropometric and behavioral characteristics associated with weight maintenance after an obesity treatment.

STUDY DESIGN

Adolescents (n = 72) enrolled in a 9-month obesity treatment were observed 1 and 2 years after discharge. Two groups, "successful" versus "limited or no success," were created on the basis of the differences in body mass index (BMI) z-score between inclusion and end of follow-up. Anthropometric and behavioral characteristics were compared between groups.

RESULTS

Both groups showed a decrease in BMI z-score between inclusion and end of follow-up, 2.09 +/- 0.68 SD for the successful group and 0.65 +/- 0.43 SD for the group with limited or no success. Groups did not differ during treatment for any of the anthropometric characteristics considered, whereas differences clearly appeared 1 year after treatment and generally stabilized during the second year. Later adiposity rebound, trend for lower BMI in the mother, and, during follow-up, lower total energy intake, more energy at breakfast, and less snacking and television were recorded in the successful group.

CONCLUSIONS

Weight loss maintenance can neither be predicted with anthropometry during treatment nor with behavioral characteristics at inclusion, but can be estimated 1 year after discharge. Early life factors should also be taken into account for predicting treatment outcome.

Long-term benefit of postconditioning

BACKGROUND

We previously demonstrated that ischemic postconditioning decreases creatine kinase release, a surrogate marker for infarct size, in patients with acute myocardial infarction. Our objective was to determine whether ischemic postconditioning could afford (1) a persistent infarct size limitation and (2) an improved recovery of myocardial contractile function several months after infarction.

METHODS AND RESULTS

Patients presenting within 6 hours of the onset of chest pain, with suspicion for a first ST-segment-elevation myocardial infarction, and for whom the clinical decision was made to treat with percutaneous coronary intervention, were eligible for enrollment. After reperfusion by direct stenting, 38 patients were randomly assigned to a control (no intervention; n=21) or postconditioned group (repeated inflation and deflation of the angioplasty balloon; n=17). Infarct size was assessed both by cardiac enzyme release during early reperfusion and by 201thallium single photon emission computed tomography at 6 months after acute myocardial infarction. At 1 year, global and regional contractile function was evaluated by echocardiography. At 6 months after acute myocardial infarction, single photon emission computed tomography rest-redistribution index (a surrogate for infarct size) averaged 11.8+/-10.3% versus 19.5+/-13.3% in the postconditioned versus control group (P=0.04), in agreement with the significant reduction in creatine kinase and troponin I release observed in the postconditioned versus control group (-40% and -47%, respectively). At 1 year, the postconditioned group exhibited a 7% increase in left ventricular ejection fraction compared with control (P=0.04).

CONCLUSIONS

Postconditioning affords persistent infarct size reduction and improves long-term functional recovery in patients with acute myocardial infarction.

In Vivo Characterization of Murine Myocardial Perfusion With Myocardial Contrast Echocardiography

Background— The ability to noninvasively evaluate murine myocardial blood flow (MBF) in vivo would provide an important tool for cardiovascular research. Myocardial contrast echocardiography (MCE) has been used to measure MBF; however, it has not been validated in mice. This study assesses whether MCE can evaluate MBF at rest and after vasodilation and measure the maximal augmentation (coronary reserve) of MBF in mice. Wild-type (WT) and nitric oxide synthase 3 (NOS3)–deficient (NOS3 −/− ) mice were studied.

Methods and Results— MCE was performed at baseline and after intravenous infusion of acetylcholine or adenosine. Definity contrast agent was infused, and parasternal views were acquired in real-time mode. Replenishment curves of myocardial contrast were obtained, and rates of signal rise (β) and plateau intensity (A) were calculated. MBF estimated by the product of A and β (Aβ) was compared with that measured with fluorescent microspheres. MCE analysis was feasible in 98% (52/53) of mice. MBF measured by microspheres increased with adenosine and correlated closely with Aβ. There was no difference in MCE-derived MBF between WT and NOS3 −/− mice at rest. Adenosine infusion increased MBF by 3.0±0.6-fold in NOS3 −/− mice and 2.5±0.3-fold in WT ( P =0.58 between genotypes). Acetylcholine induced an increase of 2.4±0.2-fold in MBF in WT mice but did not increase MBF in NOS3 −/− mice ( P <0.0005 versus WT).

Conclusions— MBF, coronary reserve, and vasodilator responses can be evaluated accurately in the intact mouse by MCE. This method demonstrated a preserved coronary response to adenosine but an impaired acetylcholine-induced vasodilation in NOS3 −/− mice compared with WT mice.

Inhibition of mitochondrial permeability transition improves functional recovery and reduces mortality following acute myocardial infarction in mice

Inhibition of mitochondrial permeability transition pore (mPTP) opening by cyclosporin A or ischemic postconditioning attenuates lethal reperfusion injury. Its impact on major post-myocardial infarction events, including worsening of left ventricular (LV) function and death, remains unknown. We sought to determine whether pharmacological or postconditioning-induced inhibition of mPTP opening might improve functional recovery and survival following myocardial infarction in mice. Anesthetized mice underwent 25 min of ischemia and 24 h (protocol 1) or 30 days (protocol 2) of reperfusion. At reperfusion, they received no intervention (control), postconditioning (3 cycles of 1 min ischemia-1 min reperfusion), or intravenous injection of the mPTP inhibitor Debio-025 (10 mg/kg). At 24 h of reperfusion, mitochondria were isolated from the region at risk for assessment of the Ca(2+) retention capacity (CRC). Infarct size was measured by triphenyltetrazolium chloride staining. At 30 days of reperfusion, mortality and LV contractile function (echocardiography) were evaluated. Postconditioning and Debio-025 significantly improved Ca(2+) retention capacity (132 +/- 13 and 153 +/- 31 vs. 53 +/- 16 nmol Ca(2+)/mg protein in control) and reduced infarct size to 35 +/- 4 and 32 +/- 7% of area at risk vs. 61 +/- 6% in control (P < 0.05). At 30 days, ejection fraction averaged 74 +/- 6 and 77 +/- 6% in postconditioned and Debio-025 groups, respectively, vs. 62 +/- 12% in the control group (P < 0.05). At 30 days, survival was improved from 58% in the control group to 92 and 89% in postconditioned and Debio-025 groups, respectively. Inhibition of mitochondrial permeability transition at reperfusion improves functional recovery and mortality in mice.

Postconditioning in man

Acute myocardial infarction is the leading cause of morbidity and mortality in industrialized countries. Ischemic postconditioning, that consists of repeated brief episodes of ischemia-reperfusion performed just after reflow following a prolonged ischemic insult, dramatically reduces infarct size in animal models. Recent data indicate that it might involve the activation of the PI3-kinase-Akt-eNOS as well as PKC signalling pathways and inhibition of the opening of the permeability transition pore. A recent clinical study demonstrated that postconditioning protects the human heart. Repeated brief episodes of inflation-deflation of the angioplasty balloon performed immediately after re-opening of the culprit coronary artery reduced infarct size by 36%. Additional studies are required to determine whether infarct size limitation by postconditioning would improve functional recovery as well as patient's outcome. Further research is needed to find new pharmacological agents that would mimick postconditioning in order to treat all patients with ongoing acute myocardial infarction.

Acute myocardial infarction in mice: assessment of transmurality by strain rate imaging

In vivo evaluation of the transmural extension of myocardial infarction (TEI) is crucial to prediction of viability and prognosis. With the rise of transgenic technology, murine myocardial infarction (MI) models are increasingly used. Our study aimed to evaluate systolic strain rate (SR), a new parameter of regional function, to quantify TEI in a murine model of acute MI induced by various durations of ischemia followed by 24 h of reperfusion. Global and regional left ventricular (LV) function were assessed by echocardiography (13 MHz, Vivid 7, GE) in 4 groups of wild-type mice (C57BL/6, 2 mo old): a sham-treated group (n = 10) and three MI groups [30 (n = 11), 60 (n = 10), and 90 (n = 9) min of left coronary artery occlusion]. Conventional LV dimensions, anterior wall (AW) thickening, and peak systolic SR were measured before and 24 h after reperfusion. Area at risk (AR) was measured by blue dye and infarct size (area of necrosis, AN) and TEI by triphenyltetrazolium chloride staining. AN increased with ischemia duration (25 +/- 2%, 56 +/- 5%, 71 +/- 6% of AR for 30, 60, and 90 min, respectively; P < 0.05). LV end-diastolic volume significantly increased with ischemia duration (30 +/- 5, 34 +/- 5, 43 +/- 5 microl; P < 0.05), whereas LV ejection fraction decreased (63 +/- 5%, 58 +/- 6%, 46 +/- 5%; P < 0.05). AW thickening decrease was not influenced by ischemia duration. Conversely, systolic SR decreased with ischemia duration (13 +/- 5, 4 +/- 3, -2 +/- 6 s(-1); P < 0.05) and was significantly correlated with TEI (r = 0.89, P < 0.01). Receiver operating characteristic (ROC) curves identified systolic SR as the most accurate parameter to predict TEI. In conclusion, in a murine model of MI, SR imaging is superior to conventional echocardiography to predict TEI early after MI.

Cardiac and respiratory self-gated cine MRI in the mouse: Comparison between radial and rectilinear techniques at 7T

ECG-gated cardiac MRI in the mouse is hindered by many technical difficulties in ECG signal recording inside high magnetic field scanners. The present study proposes a robust rectilinear method of acquiring cardiac and respiratory self-gated cine images in mouse hearts. In this approach, a motion-synchronization MR signal is collected in the center of k-space simultaneously with imaging data in each readout of a nontriggered rectilinear acquisition. This signal is then used for both cardiac and respiratory retrospective gating before cine image reconstruction. The value of this approach for overcoming ECG-gating failure was demonstrated by performing cardiac imaging in eight mice with myocardial infarction. Comparison with an auto-gated radial k-space sampling technique, previously reported for cardiac applications in the mouse, found the rectilinear strategy more robust, thanks to a more reliable self-gating signal, while the radial strategy was less sensitive to motion and flow artifacts.

Silent coronaropathy: usefulness of dobutamine stress echocardiography in ischemic stroke

BACKGROUND

Several testing options are available to detect asymptomatic coronary artery disease (CAD). Dobutamine stress echocardiography (DSE) has been reported to increase the sensitivity and specificity of stress testing to detect CAD. Most studies concerned patients with known or suspected CAD who have a high pretest probability of disease. We aimed to perform a preliminary evaluation of DSE in atherothrombotic stroke.

METHODS

Patients with transient ischemic attack or nondisabling ischemic stroke attributable to an atherothrombotic source were prospectively recruited. Patients with a history of angina pectoris or electrocardiographic signs of previous myocardial infarction were excluded. DSE was considered positive when regional reduction or deterioration of myocardial thickening developed in 1 segment. Coronary angiography was performed in patients with positive DSE.

RESULTS

Sixty-four patients were recruited. Analysis of DSE was possible in 60 patients. Overall the test provided clinically useful information in 60/64 patients studied (>90%). DSE was positive in 9 patients (15%). Coronary angiography was performed in 8 patients, high-grade focal lesions were found in 3 patients, and 5 patients showed diffuse atheroma. Univariate logistic regression analysis showed that the main factor predictive of a positive DSE was the presence of an aortic arch atheroma (p = 0.003). Multivariate logistic regression analysis showed that two factors had an independent predictive value of positive DSE: aortic arch atheroma (p = 0.007) and dyslipidemia (p = 0.09).

CONCLUSION

DSE may improve prevention of further vascular events in patients with an atherothrombotic source of ischemic stroke. This screening may be of particular benefit to patients with an aortic arch atheroma.

Quantitative Analysis of Myocardial Perfusion in Rats by Contrast Echocardiography

BACKGROUND

The ability to assess myocardial perfusion in small animals is important, especially to investigate models of myocardial ischemia. Myocardial perfusion is usually assessed by postmortem techniques, eliminating the possibility of follow-up. We sought to evaluate whether contrast echocardiography was able to quantify myocardial perfusion in rats.

METHODS

Twenty-four rats divided in 3 groups (sham-operated, and 8 and 21 days after left anterior descending coronary artery stenosis) underwent myocardial contrast echocardiography using intermittent triggered imaging. Peak plateau intensity and slope of refilling were compared with myocardial blood flow achieved with fluorescent microspheres.

RESULTS

High-quality images were easily obtained for each experiment. Close correlation was found between myocardial contrast echocardiography and myocardial blood flow, especially for measurements of peak plateau intensity x slope of refilling relative to the control area (y = 1.15 x -0.14, r = 0.86).

CONCLUSION

Quantification of myocardial perfusion in rats is feasible by myocardial contrast echocardiography using intermittent triggered imaging.

Can contrast dobutamine stress echocardiography be performed with standardized imaging settings for everybody?

OBJECTIVE

The objective was to assess a standardized imaging and contrast injection protocol for contrast-enhanced dobutamine stress echocardiography (DSE).

METHODS

A total of 102 patients underwent DSE with tissue harmonic imaging and a standardized protocol with contrast power modulation. Contrast intensities in the left ventricular cavity and the myocardium were evaluated by a visual score and quantitative analysis.

RESULTS

Of the contrast studies, 98% were diagnostic without modification of the settings. Excellent endocardial border definition was found in 93% of the segments with contrast versus 53% with tissue harmonic imaging (P < .05). The interobserver agreement in assessing segmental wall motion improved from 71.5% to 85.9%. There were no differences between the myocardial segments' video intensity in the four- and three-chamber views. In the two-chamber view video intensity was lower in the basal segments compared with the other segments.

CONCLUSION

Power modulation contrast imaging can be applied with a completely standardized protocol for DSE in the majority of patients with excellent endocardial border definition.

Tissue Doppler imaging detects early asymptomatic myocardial abnormalities in a dog model of Duchenne?s cardiomyopathy

AIMS

Early diagnosis of Duchenne's dilated cardiomyopathy remains a challenge for conventional echocardiography. We sought to determine whether tissue Doppler imaging (TDI) could detect early alteration in myocardial function in a dog model of Duchenne muscular dystrophy, i.e. the Golden Retriever Muscular Dystrophy (GRMD).

METHODS AND RESULTS

Myocardial function was assessed by TDI in 20 dogs with normal conventional parameters of systolic function (eight controls and 12 GRMD, 25+/-11 weeks) without knowledge of the genotype. M-mode TDI was recorded from a short-axis view for measurement of endocardial and epicardial velocities and myocardial velocity gradient (MVG) within the posterior wall. Controls and GRMD dogs were comparable regarding left ventricular fractional shortening (37+/-2 vs 42+/-3%, p=ns). Conversely, TDI showed, in all GRMD dogs, a dramatic decrease in systolic MVG (0.8+/-0.1 vs 2.9+/-0.3 s(-1), p<0.0001) and early diastolic MVG (2.3+/-2.2 vs 10.8+/-1.1 s(-1), p<0.0001). This MVG alteration was related to a significant decrease in endocardial velocities in GRMD whereas epicardial velocities were comparable in the two groups.

CONCLUSION

These results show that TDI is more sensitive than conventional echocardiography in detecting pre-clinical myocardial abnormalities before occurrence of left ventricular dilation and dysfunction. TDI should be part of the screening techniques for the early diagnosis of cardiomyopathy.

Increased poliovirus-specific intestinal antibody response coincides with promotion of Bifidobacterium longum-infantis and Bifidobacterium breve in infants: a randomized, double-blind, placebo-controlled trial

To determine whether the size of the intestinal bifidobacterial population can influence the immune response to poliovirus vaccination in infants, we set up a randomized, placebo-controlled trial. From birth to 4 mo, infants were given a fermented infant formula (FIF) or a standard formula (placebo). Bifidobacteria were quantified monthly in infant stools. Antipoliovirus IgA response to Pentacoq was assessed before and 1 mo after the second vaccine injection. Thirty infants were randomized, and 20 completed the study (nine in the placebo group and 11 in the FIF group). Fecal bifidobacterial level was significantly higher with the FIF group at 4 mo of age (p=0.0498). Furthermore, B. longum/B. infantis carriage was higher at 4 mo in the FIF group (p=0.0399). Antipoliovirus IgA titers increased after Pentacoq challenge (p <0.001), and the rise was significantly higher in the FIF group (p <0.02). Antibody titers correlated with bifidobacteria, especially with B. longum/B. infantis and B. breve levels (p <0.002). Infants who harbored B. longum/B. infantis also exhibited higher levels of antipoliovirus IgAs (p <0.002). In conclusion, the present results indicate that antipoliovirus response can be triggered with a fermented formula that is able to favor intestinal bifidobacteria. Whether this effect on the immune system is achieved through the bifidogenic effect of the formula (mainly through B. longum/B. infantis and B. breve stimulation) or directly linked to compounds (i.e. peptides) produced by milk fermentation remains to be investigated.

Effects of long-term consumption of a fermented infant formula (with Bifidobacterium breve c50 and Streptococcus thermophilus 065) on acute diarrhea in healthy infants

OBJECTIVE

To determine whether long-term consumption of a fermented infant formula could influence the incidence of acute diarrhea and its severity in healthy infants.

METHOD

Nine hundred seventy-one infants, ranging in age from 4 to 6 months, were included in a randomized, double-blind, placebo-controlled trial during a period of 5 months. They consumed daily either a fermented infant formula (FF) (fermentation with Bifidobacterium breve C50 and Streptococcus thermophilus 065) or a standard infant formula (SF) of the same nutritional composition.

EVALUATION CRITERIA

Number and duration of acute diarrhea episodes were evaluated. Severity of the episodes was determined by the number of hospital admissions, incidence of dehydration, number of medical consultations, number of oral rehydration solution prescriptions, and number of formula switches.

RESULTS

Growth of the infants and acceptability of the formulas were identical in the two groups. Incidence, duration of diarrhea episodes, and number of hospital admissions did not differ significantly between groups. Episodes were less severe in the FF (fermented formula) group. There were fewer cases of dehydration 2.5%versus 6.1% (P = 0.01), fewer medical consultations (46%v 56.6%, P = 0.003), fewer ORS prescriptions 41.9%v 51.9% (P = 0.003) and fewer switches to other formulas (59.5%v 74.9%, P = 0.0001) in FF infants compared to SF.

CONCLUSION

A fermented formula may reduce the severity of acute diarrhea among healthy young infants. This outcome may be linked to the bifidogenic effects of fermentation products and their interactions with the intestinal immune system.

Massive obesity in adolescents: dietary interventions and behaviours associated with weight regain at 2 y follow-up

OBJECTIVE

To compare the influence of weight-reducing diets containing different amounts of protein and CHO on body composition in obese adolescents and to examine dietary and physical activity behaviours during follow-up.

METHODOLOGY

DESIGN

Prospective randomised study comparing two weight-reducing diets with the same energy (1750 kcal) and fat (31%) content, but different protein and carbohydrate contents: PROT- (15% protein, 54% CHO) vs PROT+ (19% protein, 50% CHO).

PATIENTS

Massively obese 11- to 16-year-old children (32 boys and 89 girls).

SETTING

A 9-month treatment in a medical centre (boarding school) plus a 2-y follow-up in free-living patients examined at home 1 and 2 y after treatment.

MEASUREMENTS

Anthropometry, bioelectrical impedance, nutritional intakes and physical activity.

RESULTS

Of the 121 eligible children (61 in PROT- and 60 in PROT+), 82% completed the trial until the end of weight loss treatment and 60% were followed 2 y after treatment. Body mass index (BMI) value at inclusion was 36.3 kg/m(2) or 4.3 z-scores (2.9-5.9). BMI z-score decreased to 1.7 at the end of treatment and went back to 2.8 (0.8-6.1) 2 y after treatment. This corresponded to a weight loss of 30.3 kg and weight regain of 21.3 kg. After treatment, energy intake increased and physical activity decreased. The contribution of energy ingested at breakfast decreased while snacking increased. For all measurements, no dietary group differences existed at baseline or at any time during the intervention and follow-up.

CONCLUSION

A higher protein content of the diet did not confer any benefit in the treatment of childhood obesity. Substantial weight loss was obtained with a moderately energy-restricted diet and normal fat content. After weight loss, mean weight increased in spite of moderate energy intake, together with a drift towards obesity-associated behavioural patterns. The causes of the inability to adopt normal weight subjects' behaviour permanently deserve to be investigated further.

Stratégies de prévention de l’obésité chez l’enfant

Considering the high prevalence and the increasing trends, obesity is now considered as a public health problem in numerous countries. The main aim of the National Program of Nutrition and Health is to stop the increasing prevalence of childhood obesity. In this frame work, a group of experts has established a new presentation of the corpulence curves, adapted for clinical practice, to define normal weight and obesity. Weight status is now currently assessed on the basis of weight and height measurements, after computing the Quetelet index or body mass index (BMI) corresponding to weight (m) divided by square of height (weight/height2). As body proportion varies during growth, age must be taken into account. Various curves were published. In 1982, based on the French sample of the international growth study, BMI curves were published. They were revised in 1991. The third and 97th centiles define the normal weight range. Overweight is defined by BMI values greater than the 97th centile. In the year 2000, a new international definition was established. Two centiles were constructed to define overweight and obesity. The new BMI charts adapted for clinical practice, proposed by the French National program of nutrition and health, include the French reference curves plus the centile defining obesity in the international definition. Thus, in the new French charts, the area above the 97th centile is split in two levels (degree 1 obesity and degree 2 obesity). Drawing the BMI curve for each child, like drawing weight and height curves, is a simple act which can be done routinely. The age at adiposity rebound (an indicator predicting the risk of adult obesity) can be read from the curve. It allows to identify an early phase of obesity development, even at the time when overweight is not yet clinically visible. When obesity appears clearly, the identification is easy. The use of BMI curves is particularly useful in two situations: (1) in very young overweight children, the curves allow to identify children who have a real risk of developing obesity. (2) By the age of 6 years, when due to normal physiological variations, clinical assessment can be misleading. The BMI curves allow to identify children at risk. When a child is identified as having a real risk of obesity, simple preventive measures, adapted for each subject, could avoid a development toward massive obesity, which may become difficult to reduce if managed too late.

Ambulatory nursing: profiling the scope of practice in a paediatric teaching hospital

The article discusses how one hospital with a large outpatient service, evaluated the role of nursing in ambulatory care. Using a validated conceptual framework consisting of Ambulatory Care Areas of Responsibility and Nursing Activities, data was collected and a profile was created detailing the nursing role in each clinic or service.

[Transient neonatal hyperthyroidism caused by transplacental transport of pituitary TSH receptor antibodies]

BACKGROUND

Neonatal hyperthyroidism is a relatively rare condition. It can be severe and difficult to treat when the maternal hyperthyroidism has recently been recognized.

CASE REPORT

A baby was born at 37 weeks of gestational age to a mother whose hyperthyroidism was only suspected at the 34th week. The mother was not given propylthiouracil until the day before delivery. At birth, the newborn presented with meconial fluid; it weighed 2,380 grams, was 46 cm long and had a head circumference of 32 cm. Clinical examination showed exophthalmos, tachycardia, hepatosplenomegaly, restlessness, moderate goiter and premature craniosynostosis. Laboratory data showed elevated serum free T4 (76 pmol/l), unmeasurable TSH, and the presence of thyroid-stimulating immunoglobulins. The infant was given propranolol (10 mg/day), and carbimazol (3.75 mg/day) from day 13. Clinical and biological improvement allowed the carbimazol to be stopped at 1 month. A relapse was treated with carbimazol plus L-thyroxine. Both drugs were discontinued at the age of 4 months. At 12 months, the baby is perfectly well and has developed normally.

CONCLUSION

This transient thyrotoxicosis was due to the transplacental passage of TSH receptor antibodies. Its management was difficult because the mother was treated late during her pregnancy.

[Treatment of hyperthyroidism in children with antithyroid drugs]

Sixteen cases of pediatric hyperthyroidism treated by antithyroid drugs are reported. First-line treatment with carbimazole in a mean dose of 19 mg/m2 initially and 7 mg/m2 after one year ensured control of the disease within 6 weeks. Mean follow-up was 4 years. Only two children were able to discontinue the drug, after 9.1 years and 4.6 years. Two other patients had thyroidectomy, after 6.7 years and 3.4 years. The main disadvantages of antithyroid drugs are the need for prolonged treatment and the risk of recurrence. An attempt at treatment discontinuation is warranted in patients with good disease control of 2 to 3 years duration, goiter size reduction, improved exophthalmos, and decreased anti-TSH receptor antibodies.

The immune response in iron-deficient young children: effect of iron supplementation on cell-mediated immunity

The effects of iron deficiency on immunity remain controversial. This study was designed to assess the impact of iron supplementation on the immune status, in 81 children aged 6 months-3 years, at high risk for iron deficiency, using a longitudinal double blind randomised and placebo-controlled study. Lymphocytes of iron-deficient children produced less interleukin-2 in vitro. Iron supplementation for 2 months increased mean corpuscular volume, serum ferritin and serum transferrin, but had no effect on the parameters of T-cell mediated immunity. The lower interleukin-2 levels in iron-deficient suggest that cell-mediated immunity may be impaired in iron deficiency.

Idiopathic prepubertal short stature is associated with low body mass index

The hypothesis that insufficient body weight is partly responsible for idiopathic short stature was tested by evaluating 79 prepubertal children having idiopathic short stature, classified according to their body mass index (BMI) zs: group 1 BMI zs < or = 0 (m +/- SE, -0.9 +/- 0.1, n = 53) and group 2 BMI zs > 0 (0.6 +/- 0.1, n = 26). Their ages were similar (8.1 +/- 0.3 and 8.4 +/- 0.4 years). The following parameters were significantly lower in group 1 than in group 2: height (-2.5 +/- 0.1 vs. -2.2 +/- 0.1 SD, p < 0.05), height velocity (-1.5 +/- 0.2 vs. -0.9 +/- 0.4 SD, p < 0.05), bone age (bone age retardation 2.3 +/- 0.2 vs. 1.3 +/- 0.4 years, p < 0.005) and plasma insulin-like growth factor 1 (IGF-1, 0.8 +/- 0.1 vs. 1.2 +/- 0.1 U/ml, p < 0.05). The BMI was significantly lower in children with idiopathic short stature (-0.4 +/- 0.1) than in the normal population (zs, p < 0.0002). BMI zs was positively correlated with height (p < 0.005), height velocity (p < 0.05) and plasma IGF-1 (p < 0.01). We conclude that children with idiopathic short stature are leaner than the normal population. An inadequate or insufficient nutritional intake may be partly responsible for idiopathic short stature. The effects of improved intake on the height change are under evaluation.

Interleukin 2 production in iron-deficient children

The relationship between iron status and capacity for IL-2 production by lymphocytes was assessed in 81 children from 6 mo to 3 yr of age selected at random from a population with low socioeconomic status, undergoing free systematic examination in four children's health centers in the Paris area. Iron deficiency was defined by the existence of at least two abnormal values among the three indicators of iron status: serum ferritin level less than or equal to 12 micrograms/L, transferrin saturation less than 12%, and erythrocyte protoporphyrin concentration greater than 3 micrograms/g hemoglobin. According to this definition, 53 children were classified as iron deficient and 28 as iron sufficient. No differences were observed between the iron-deficient and iron-sufficient groups in terms of the IL-2 concentration without stimulation by PHA. IL-2 production by lymphocytes stimulated with PHA, as well as the stimulation index (ratio of IL-2 concentration following stimulation by PHA to that of IL-2 concentration without stimulation by PHA) were significantly lower in iron-deficient children. The reduction in IL-2 production by activated lymphocytes observed in our study of iron-deficient children may be responsible for impairments in immunity found by other authors, particularly in cell-mediated immunity.