Echocardiographic myocardial deformation evaluation of right ventricular function in comparison with CMRI in repaired tetralogy of Fallot: a cross-sectional and longitudinal validation study.

BACKGROUND: Decreased right ventricular (RV) ejection fraction (EF) increases morbidity in repaired tetralogy of Fallot (rToF). Cardiac magnetic resonance (CMR) is the accepted reference standard for RV EF measurement. There are no established color Doppler tissue imaging (cDTI) values that identify decreased RV EF in rToF. We sought to assess accuracy of cDTI myocardial deformation and velocity indices in predicting CMR-derived RV EF. METHODS: Retrospective evaluation of CMR and echocardiography studies performed on the same day. cDTI-derived peak systolic velocity (pkS), isovolumic acceleration (IVA) of the tricuspid valve annulus, strain (ε) and strain rate (SR) of the RV free wall, adjusted for age, volume and pressure overload were used to compute RV EF. The probability of correctly classifying CMR measured RV EF <45% was estimated by logistic regression analysis. The accuracy of the model was tested on 10 prospective patients. RESULTS: Sixty matched echocardiographic and CMR studies were analyzed. None of the individual cDTI parameters could reliably identify patients with CMR-derived decreased RV EF. However, when adjusted for age in a logistic model: Y = -0.5 - 0.07 × age + 0.016 × Îµ + 0.46 × pkS, where Y is the logit (log odds), patients with RV EF <45% were identified with 86% sensitivity, 93.5% specificity. Prospective application of this model correctly identified all subjects with RV EF <45%. CONCLUSION: The age-adjusted logistic model and not individual parameters, derived from cDTI-derived pkS, and ε can reliably identify patients with decreased RV EF <45%.

A comparison of echocardiographic techniques in determination of arterial elasticity in the pediatric population.

BACKGROUND: Many methods are used to measure arterial elasticity in children using echocardiography. There is no data to support the equivalence of the different techniques. The goal of this study was to evaluate the reproducibility of several techniques used to measure arterial elasticity using echocardiography. METHODS: Aortic distension in two different sites (arterial distension) through the cardiac cycle was measured by (four) two-dimensional (2D) and M-mode echocardiographic techniques in 20 children without significant structural heart disease. These measurements combined with noninvasive blood pressure measurements were used to calculate arterial elastic indices. Arterial elasticity was expressed in terms of distensibility and stiffness. Data were collected by two sonographers and interpreted by two reviewers. Paired Student's t-test and Pitman's test for equality of variance for correlated observations were used to detect differences between different sonographers, different reviewers, and different techniques. RESULTS: No significant difference in the measured elasticity between sonographers or reviewers was observed. There was a somewhat increased variance in two of the four techniques evaluated. There was no significant difference in elasticity measured using different techniques to evaluate the same arterial site, although a significantly decreased elasticity was noted from measurements taken in the proximal ascending aorta as compared with the distal ascending aorta. CONCLUSIONS: Many echocardiographic techniques produce reproducible measurements of arterial elasticity. There may be intrinsic differences in arterial elasticity between different segments of the ascending aorta, which have not been previously described in children with normal cardiac anatomy. Comparisons of data from separate studies must take these differences into account.

Using the intraoperative hand held probe without lymphoscintigraphy or using only dye correlates with higher sensory morbidity following sentinel lymph node biopsy in breast cancer: a review of the literature.

BACKGROUND: There are no studies that have directly investigated the incremental reduction in sensory morbidity that lymphoscintigraphy images (LS) and triangulated body marking or other skin marking techniques provide during sentinel lymph node biopsy (SLNB) compared to using only the probe without LS and skin marking or using only dye. However, an indirect assessment of this potential for additional sensory morbidity reduction is possible by extracting morbidity data from studies comparing the morbidity of SLNB to that of axillary lymph node dissection. METHODS: A literature search yielded 13 articles that had data on sensory morbidity at specific time points on pain, numbness or paresthesia from SLNB that used radiotracer and probe or used only dye as a primary method of finding the sentinel node (SN). Of these, 10 utilized LS, while 3 did not utilize LS. By matching the data in studies not employing LS to the studies that did, comparisons regarding the percentage of patients experiencing pain, numbness/paresthesia after SLNB could be reasonably attempted at a cutoff of 9 months. RESULTS: In the 7 studies reporting on pain after 9 months (> 9 months) that used LS (1347 patients), 13.8% of patients reported these symptoms, while in the one study that did not use LS (143 patients), 28.7% of patients reported these symptoms at > 9 months (P < 0.0001). In the 6 studies reporting on numbness and/or paresthesia at > 9 months that used LS (601 patients), 12.5% of patients reported these symptoms, while in the 3 studies that did not use LS (229 patients), 23.1% of patients reported these symptoms at > 9 months (P = 0.0002). Similar trends were also noted for all these symptoms at < or = 9 months. CONCLUSION: Because of variations in techniques and time of assessing morbidity, direct comparisons between studies are difficult. Nevertheless at a minimum, a clear trend is present: having the LS images and skin markings to assist during SLNB appears to yield more favorable morbidity outcomes for the patients compared to performing SLNB with only the probe or performing SLNB with dye alone. These results are extremely pertinent, as the main reason for performing SLNB itself in the first place is to achieve reduced morbidity.

The impact of obesity on health service utilization and costs in childhood.

Most studies of the economic costs of childhood obesity have focused upon hospitalization for comorbidities of obesity, whereas increased expenditures may also be the result of additional outpatient/emergency room visits or prescription drug expenditures. To quantify the magnitude of increased health-care utilization and expenditures among overweight and obese children, we performed descriptive, bivariate, and multivariable analyses on data from 6- to 19-year olds in the 2002-2005 Medical Expenditure Panel Survey (MEPS), a national probability survey of the noninstitutionalized civilian population in the United States. Compared with normal/underweight children, we found that children who were obese during both years of the MEPS had USD194 higher outpatient visit expenditures, USD114 higher prescription drug expenditures, and USD12 higher emergency room expenditures. Children who were overweight during both years, or overweight in one year and obese in the other had USD79 higher outpatient visit expenditures, USD64 higher prescription drug expenditures, and USD25 higher emergency room expenditures than normal/underweight children. Significantly, increased utilization was noted for outpatient visits, prescription drug use, and emergency room visits. Increased costs and utilization were concentrated among adolescents, though 6-11-year-old children who were obese in both years did have more outpatient visits and expenditures than other children. Extrapolated to the nation, elevated BMI in childhood was associated with USD14.1 billion in additional prescription drug, emergency room, and outpatient visit costs annually. Although further research is needed to identify effective interventions, the immediate economic consequences of childhood obesity are much greater than previously realized, and further reinforce efforts to prevent this major comorbidity are needed.

Relation of coarctation of the aorta to the occurrence of ascending aortic dilation in children and young adults with bicuspid aortic valves.

Children with bicuspid aortic valve (BAV) have aortic dilation that is present and progressive from birth irrespective of the functional state of the valve. There are no published data comparing aortic dilation in children with BAV with and without aortic coarctation (CoA). The objectives of this study were to (1) compare differences in aortic dimensions and rates of dilation between children with isolated BAV with those of children with BAV and CoA and (2) identify risk factors for the development of aortic dilation. Patients with BAV with CoA (group A) and without CoA (group B) were identified from our echocardiographic database (1993 to 2006). Aortic measurements at 4 levels were obtained, and z scores were compared. Criteria for exclusion were severe aortic regurgitation/stenosis, previous aortic valvuloplasty, complex left-sided cardiac disease, ventricular septal defects, and Turner, Noonan, Williams, and Marfan syndromes. There were 600 echocardiograms in 247 patients. Group A had 192 echocardiograms in 53 patients (median age 11.3 years; range 0 to 30; median follow-up 7 years), and group B had 382 in 194 patients (median age 8.7 years; range 0 to 29; median follow-up 4 years). Group B had significantly greater ascending aorta dimensions (p<0.05) and significantly faster rates of aortic dilation (p<0.0001). The ascending aorta in patients with BAV and CoA did not dilate to the same degree as in patients with isolated BAV. In conclusion, valve morphologic characteristics and function and age at CoA repair had none to minimal impact on aortic dimensions.

Black/white differences in very low birth weight neonatal mortality rates among New York City hospitals.

OBJECTIVE: We sought to determine whether differences in the hospitals at which black and white infants are born contribute to black/white disparities in very low birth weight neonatal mortality rates in New York City. METHODS: We performed a population-based cohort study using New York City vital statistics records on all live births and deaths of infants weighing 500 to 1499 g who were born in 45 hospitals between January 1, 1996, and December 31, 2001 (N = 11 781). We measured very low birth weight risk-adjusted neonatal mortality rates for each New York City hospital and assessed differences in the distributions of non-Hispanic black and non-Hispanic white very low birth weight births among these hospitals. RESULTS: Risk-adjusted neonatal mortality rates for very low birth weight infants in New York City hospitals ranged from 9.6 to 27.2 deaths per 1000 births. White very low birth weight infants were more likely to be born in the lowest mortality tertile of hospitals (49%), compared with black very low birth weight infants (29%). We estimated that, if black women delivered in the same hospitals as white women, then black very low birth weight mortality rates would be reduced by 6.7 deaths per 1000 very low birth weight births, removing 34.5% of the black/white disparity in very low birth weight neonatal mortality rates in New York City. Volume of very low birth weight deliveries was modestly associated with very low birth weight mortality rates but explained little of the racial disparity. CONCLUSION: Black very low birth weight infants more likely to be born in New York City hospitals with higher risk-adjusted neonatal mortality rates than were very low birth weight infants, contributing substantially to black-white disparities.

Strain-dependent differences in the efficiency of transgenic mouse production.

Transgenic mouse production via pronuclear microinjection is a complex process consisting of a number of sequential steps. Many different factors contribute to the effectiveness of each step and thus influence the overall efficiency of transgenic mouse production. The response of egg donor females to superovulation, the fertilization rate, egg survival after injection, ability of manipulated embryos to implant and develop to term, and concentration and purity of the injected DNA all contribute to transgenic production efficiency. We evaluated and compared the efficiency of transgenic mouse production using four different egg donor mouse strains: B6D2/F1 hybrids, Swiss Webster (SW) outbred, and inbred FVB/N and C57BL/6. The data included experiments involving approximately 350 DNA transgene constructs performed by a high capacity core transgenic mouse facility. Significant influences of particular genetic backgrounds on the efficiency of different steps of the production process were found. Except for egg production, FVB/N mice consistently produced the highest efficiency of transgenic mouse production at each step of the process. B6D2/F2 hybrid eggs are also quite efficient, but lyze more frequently than FVB/N eggs after DNA microinjection. SW eggs on the other hand block at the 1-cell stage more often than eggs from the other strains. Finally, using C57BL/6 eggs the main limiting factor is that the fetuses derived from injected eggs do not develop to term as often as the other strains. Based on our studies, the procedure for transgenic mouse production can be modified for each egg donor strain in order to overcome any deficiencies, and thus to increase the overall efficiency of transgenic mouse production.