Clinico-histopathological correlation of symptomatic left main coronary artery electrocardiographic ischemia pattern in a young child with hypertrophic cardiomyopathy

The specific electrocardiographic (ECG) pattern of left main coronary artery ischemia is exceptionally rare in children and under recognized. Occasional reports are bereft of a detailed mechanistic ECG description and limited to dissection, spasm, or anomalous origin of the left main coronary artery. An association with pediatric hypertrophic cardiomyopathy (HCM) is hitherto unreported. We furbish a detailed electrocardiographic description of this entity in the unusual setting of a 4-year-old child with HCM with a restrictive phenotype and exertional symptoms consistent with myocardial ischemia. Heart transplant was performed for this rare indication. Histopathology of the explanted heart in particular revealed left main coronary artery narrowing and provided us with a unique window of opportunity to correlate with clinical findings. The pathophysiology was also likely exacerbated by diffuse sub endocardial ischemia in the milieu of left ventricular hypertrophy with elevated end diastolic pressures. We anticipate that this illustrative case will help contextualize this as well as pediatric scenarios in which the 'left main ischemia' ECG pattern can be encountered and foster an accurate electrocardiographic recognition of this entity in children.

Echocardiographic Indicators Associated with Adverse Clinical Course and Cardiac Sequelae in Multisystem Inflammatory Syndrome in Children with Coronavirus Disease 2019

Background

Multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 causes significant cardiovascular involvement, which can be a determinant of clinical course and outcome. The aim of this study was to investigate whether echocardiographic measures of ventricular function were independently associated with adverse clinical course and cardiac sequelae in patients with MIS-C.

Methods

In a longitudinal observational study of 54 patients with MIS-C (mean age, 6.8 ± 4.4 years; 46% male; 56% African American), measures of ventricular function and morphometry at initial presentation, predischarge, and at a median of 3- and 10-week follow-up were retrospectively analyzed and were compared with those in 108 age- and gender-matched normal control subjects. The magnitude of strain is expressed as an absolute value. Risk stratification for adverse clinical course and outcomes were analyzed among the tertiles of clinical and echocardiographic data using analysis of variance and univariate and multivariate regression.

Results

Median left ventricular apical four-chamber peak longitudinal strain (LVA4LS) and left ventricular global longitudinal strain (LVGLS) at initial presentation were significantly decreased in patients with MIS-C compared with the normal cohort (16.2% and 15.1% vs 22.3% and 22.0%, respectively, P < .01). Patients in the lowest LVA4LS tertile (<13%) had significantly higher C-reactive protein and high-sensitivity troponin, need for intensive care, and need for mechanical life support as well as longer hospital length of stay compared with those in the highest tertile (>18.5%; P < .01). Initial LVA4LS and LVGLS were normal in 13 of 54 and 10 of 39 patients, respectively. There was no mortality. In multivariate regression, only LVA4LS was associated with both the need for intensive care and length of stay. At median 10-week follow-up to date, seven of 36 patients (19%) and six of 25 patients (24%) had abnormal LVA4LS and LVGLS, respectively. Initial LVA4LS < 16.2% indicated abnormal LVA4LS at follow-up with 100% sensitivity.

Conclusion

Impaired LVGLS and LVA4LS at initial presentation independently indicate a higher risk for adverse acute clinical course and persistent subclinical left ventricular dysfunction at 10-week follow-up, suggesting that they could be applied to identify higher risk children with MIS-C.

Strain and strain rate imaging using speckle tracking in acute allograft rejection in children with heart transplantation

Acute allograft rejection is a major cause of morbidity and mortality following heart transplantation. There is no reliable noninvasive test to diagnose rejection. We aimed to investigate the accuracy of strain by speckle tracking echocardiography in the detection of acute rejection. We identified acute rejection episodes in patients followed at a single transplant center. Data were collected at baseline, during rejection and two follow-up points. Peak systolic radial and circumferential strain at the level of papillary muscles and peak systolic longitudinal strain from apical four-chamber view were analyzed offline. ANOVA was used for comparison between groups. p value ≤0.05 was considered significant. Fifteen rejection episodes were identified. There were no differences in the fractional shortening, LV posterior wall thickness, E/A, septal E/E', septal S', lateral E/E', lateral S', or MPI during rejection, compared to baseline. There was a significant increase in the LV mass during a rejection episode (47.5 vs. 34.4 g/ht(2.7) [p = 0.03]). The peak systolic radial strain (18.3 vs. 26.5; p = 0.03), longitudinal strain (-11.7 vs. -14.6; p = 0.05), and circumferential strain (-14.4 vs. -21.7; p = 0.05) declined significantly during rejection. In conclusion, peak systolic radial, longitudinal and circumferential strain decline and LV mass increases during an episode of rejection.

A teen with chest pain

Chest pain is a frequent symptom and complaint in the teenage population. There are many common, benign causes of chest pain. However, it can create tremendous anxiety in the mind of the patient and family members and sometimes it can be perplexing even for the primary providers especially if there is associated family history of premature coronary artery disease. This article focuses on the evaluation of chest pain and how to differentiate between noncardiac and cardiac causes of chest pain in teenagers.

Assessment steers learning down the right road: impact of progress testing on licensing examination performance

Although it is generally accepted that assessment steers learning, this is generally viewed as an undesirable side effect. Recent evidence suggests otherwise. Experimental studies have shown that periodic formative assessments can enhance learning over equivalent time spent in study (Roediger & Karpicke 2006). However, positive effects of assessment at a curriculum level have not been demonstrated. Progress tests are a periodic formative assessment designed to enhance learning by providing objective and cumulative feedback, and by identifying a subgroup of students who require additional remediation. McMaster adopted the progress test methods in 1992-1993, as a consequence of poor performance on a national licensing examination. This article shows the positive effect of this innovation, which amounts to an immediate increase of about one-half standard deviation in examination scores, and a consistent upward trend in performance. The immediate effect of introducing objective tests was a reduction in failure rate on the licensing examination from 19% to 4.5%. Various reasons for this improvement in performance are discussed.

Breast cancer risk with postmenopausal hormonal treatment

This review was designed to determine from the best evidence whether there is an association between postmenopausal hormonal treatment and breast cancer risk. Also, if there is an association, does it vary according to duration and cessation of use, type of regimen, type of hormonal product or route of administration; whether there is a differential effect on risk of lobular and ductal cancer; and whether hormone treatment is associated with breast cancers that have better prognostic factors? Data sources for the review included Medline, the Cochrane Database of Systematic Reviews (Cochrane Library, 2005) and reference lists in the identified citations. Eligible citations addressed invasive breast cancer risk among postmenopausal women and involved use of the estrogen products with or without progestin that are used as treatment for menopausal symptoms. Abstracted data were demographic groupings, categories of hormone use, categories of breast cancer, two-by-two tables of exposure and outcome and adjusted odds ratios, relative risks (RRs) or hazard rates. Average estimates of risk were weighted by the inverse variance method, or if heterogeneous, using a random effects model. The average risk of invasive breast cancer with estrogen use was 0.79 [95% confidence interval (95% CI) = 0.61-1.02] in four randomized trials involving 12 643 women. The average breast cancer risk with estrogen-progestin use was 1.24 (95% CI = 1.03-1.50) in four randomized trials involving 19 756 women. The average risks reported in recent epidemiological studies were higher: 1.18 (95% CI = 1.01-1.38) with current use of estrogen alone and 1.70 (95% CI = 1.36-2.17) with current use of estrogen-progestin. The association of breast cancer with current use was stronger than the association with ever use, which includes past use. For past use, the increased breast cancer risk diminished soon after discontinuing hormones and normalized within 5 years. Reasonably adequate data do not show that breast cancer risk varies significantly with different types of estrogen or progestin preparations, lower dosages or different routes of administration, although there is a small difference between sequential and continuous progestin regimens. Epidemiological studies indicate that estrogen-progestin use increases risk of lobular more than ductal breast cancer, but the number of studies and cases of lobular cancer remains limited. Among important prognostic factors, the stage and grade in breast cancers associated with hormone use [corrected] do not differ significantly from those in non-users, but breast cancers in estrogen-progestin users are significantly more likely to be estrogen receptor (ER) positive. In conclusion, valid evidence from randomized controlled trials (RCTs) indicates that breast cancer risk is increased with estrogen-progestin use more than with estrogen alone. Epidemiological evidence involving more than 1.5 million women agrees broadly with the trial findings. Although new studies are unlikely to alter the key findings about overall breast cancer risk, research is needed, however, to determine the role of progestin, evaluate the risk of lobular cancer and delineate effects of hormone use on receptor presence, prognosis and mortality in breast cancer.

Does continuous passive motion during keyboarding affect hand blood flow and wrist function? A prospective case report

The purpose of this prospective case report was to evaluate the use of a keyboard platform device that uses continuous passive motion (CPM) on vascular flow to the hand for clerical employees who perform daily keyboarding tasks. Subjects were two female volunteers, one symptomatic of carpal tunnel syndrome (CTS), who were employed in clerical positions and perform daily keyboarding tasks for most of their workday. Data collection consisted of baseline and follow-up measurements at 6 weeks, including: 1) screening for symptoms based on the Carpal Tunnel Function Disability Form, 2) evaluation using standard physical therapy examination and assessment techniques, including modified Semmes- Weinstein monofilament testing, 3) a typing productivity test, and 4) Doppler ultrasound examination to quantify vascular flow at the wrist. Results revealed that both subjects demonstrated an overall increase in both radial and ulnar blood flow velocity with no decrement in typing productivity. The symptomatic subject also demonstrated an overall improvement of 10 wpm in the typing tests, a decrease in her disability score and symptom severity, and improvement in function. Results suggest that use of CPM as a non-intrusive ergonomic intervention may be used to treat, as well as prevent, carpal tunnel-like symptoms in those who keyboard.

The SOGC statement on the WHI report on estrogen and progestin use in postmenopausal women

The recent Women's Health Initiative study report evaluated the long-term benefits and risks of hormone replacement therapy among healthy postmenopausal women. The report showed that the risk-benefit profile of continuous combined hormone replacement therapy was not consistent with the primary prevention of coronary heart disease. The Women's Health Initiative study of continuous combined hormone replacement therapy is a landmark study and the results provide valuable information for patients and clinicians. However, the most common indication for hormone replacement therapy is menopausal symptoms, for which it is effective, not prevention of disease, and the most common use is for less than three years. Nevertheless, even short-term use has small effects on some outcomes. This statement discusses how the findings of the Women's Health Initiative study can be applied to reach appropriate clinical decisions.

Changes in spine and radius bone density during long-term hormone replacement

Lumbar spine and mid-radius bone mineral density was measured repeatedly in 48 postmenopausal women who completed 7 years of taking either a 500 mg·day-1 calcium supplement (n = 22) or calcium supplementation with hormone replacement therapy. The hormone replacement was either a low dose (n = 15) or a moderate dose (n = 11) regime. The purpose of the measurements was to establish the long-term pattern of change in bone mineral mass produced by continued hormone replacement. The calcium-only group lost bone mineral mass at the radius, while at the spine, bone was preserved. Low dose hormone replacement preserved radius bone. Moderate dose replacement increased bone mineral mass at the spine and preserved radius bone.Key words: calcium supplementation, long-term hormone replacement, lumbar spine bone mineral density, radius bone mineral density.

Changes in spine and radius bone density during long-term hormone replacement

Lumbar spine and mid-radius bone mineral density was measured repeatedly in 48 postmenopausal women who completed 7 years of taking either a 500 mg x day(-1) calcium supplement (n = 22) or calcium supplementation with hormone replacement therapy. The hormone replacement was either a low dose (n = 15) or a moderate dose (n = regime. The purpose of the measurements was to establish the long-term pattern of change in bone mineral mass produced by continued hormone replacement. The calcium-only group lost bone mineral mass at the radius, while the spine, bone was preserved. Low dose hormone replacement preserved radius bone. Moderate dose replacement increased bone mineral mass at the spine and preserved radius bone.

Characterization of the infection of Aedes albopictus cell clones by Sindbis virus

We have investigated the infection of Aedes albopictus (mosquito) cell clones by Sindbis virus. Variation in the multiplicity of infection (MOI) from ranges of 50-0.00005 pfu/cell was determined to have no effect on the progression of the infection to high acute phase titer, suggesting that intracellular factors alone are responsible for the restriction of virus production seen as the infection enters the persistent phase: While persistently infected (over 1 year post infection) cell clones are morphologically indistinct from uninfected cells, they do display a uniform 30% reduction in growth rate compared with uninfected cells of the same clone. Using flow cytometry-based DNA content analysis, we found that persistent Sindbis virus infection induces distinct cytological effects on these cells, including an increase in apoptosis and polyploidy in one clone and cell cycle phase effects in another. Finally, the observation that the number of cells in persistently infected cell cultures which are productively infected closely approximates the number of cells dying by apoptosis prompted us to investigate the role that cell death may play in the maintenance of the persistent infection. Persistently infected cell cultures which were artificially induced into apoptosis by short 45 degrees C heat treatments do not display increased Sindbis virus production. This result does not support the hypothesis that infection sensitivity induced by random apoptosis in persistently infected cell cultures is responsible for the long-term maintenance of the persistent infection.

Introducing progress testing in McMaster University's problem-based medical curriculum: psychometric properties and effect on learning

BACKGROUND

The progress test (or Quarterly Profile Examination), invented concurrently by the University of Missouri-Kansas City School of Medicine and the University of Limburg, is used to provide useful summative and formative judgments about students' knowledge without distorting learning. All students in all classes sit the same examination at regular intervals through the year, and their individual progress is noted. This paper reports on four years' experience with a progress test, the Personal Progress Index (PPI), at the McMaster University Faculty of Health Sciences.

METHOD

The PPI, a 180-item multiple-choice test with items drawn from all disciplines of medicine, is administered to medical students in all three classes three times per year. Individual feedback is provided, and accumulated student performance is determined for summative purposes. This paper examines extensive evidence of reliability, validity, and effect on student learning, using samples from the entering classes of 1992-1995 (a total of 400 students).

RESULTS

Reliabilities across test administrations (within classes) ranged from .46 to .63. The PPI demonstrated strong construct validity, with highly significant statistical tests of differences between classes and changes within classes on successive administrations. The predictive validity of the PPI, i.e., whether it could predict performance on the licensing examination of the Medical Council of Canada, increased monotonically from a correlation of .12 for the first test administration one month into medical school to a high of about .60 for the cumulative score across all administrations three months prior to the examination.

CONCLUSION

The PPI seems to be performing as intended, with students showing growth in performance across the three years of the MD program. Additional benefits are that many more students now self-refer for remediation (based on low PPI scores) and that the consistent relative performances of individual students across test administrations allow for the identification of students who have severe and persistent problems.

Postmenopausal bone mineral density: relationship to calcium intake, calcium absorption, residual estrogen, body composition, and physical activity

Physical and lifestyle data were collected from 62 postmenopausal women who had declined hormone replacement therapy. Potential predictor variables were examined for their associations with bone mineral density (BMD) of the lumbar spine and femoral neck as assessed by dual x-ray absorptiometry. Body weight demonstrated the strongest association with lumbar BMD; lean body mass demonstrated the strongest association with femoral BMD. Together with the natural logarithm of the number of years since menopause (ln YSM) these anthropometric variables explained 36 and 34% of the variability of femoral and lumbar BMD, respectively. Serum estradiol levels demonstrated a weak positive association with BMD, which lost statistical significance after adjustment for body mass. Similarly, cardiovascular fitness was positively associated with femoral BMD prior to but not following adjustment for body mass. Controlling for years since menopause and body mass, the product of dietary calcium and calcium absorption demonstrated a weak positive correlation with femoral BMD (partial r = 0.30). The intake of tea was positively and significantly associated with both bone density measurements. In multiple regression analysis, femoral BMD was best explained by the lean body mass, ln YSM, and the daily intake of tea (r2 = 0.50). Similarly, lumbar BMD was best explained by body weight, ln YSM, and intake of tea (r2 = 0.44). Body mass is a major predictor of postmenopausal bone density at the hip and spine. A positive association between dietary calcium and BMD was detected only by taking into account the intestinal absorptive efficiency.

Rehabilitation for children--parents can't do it all

Management of disabling conditions in children differs from that for adults, with ongoing needs related to growth and development. Parents also vary in their ability to deal with the demands placed on the family by a child with a disability. Different disabling conditions require many of the same kinds of therapies, with more emphasis on some. Functional goals include mobility, communication, independence in activities of daily living, education and eventual appropriate vocational planning. Consultation, outpatient therapy, or intensive, inpatient management may be appropriate at different times. A rehabilitation team approach with other specialists as needed can assist the child, family, and school to achieve the best outcome possible.

Hormone replacement therapy may reduce the return of endogenous lead from bone to the circulation

Hormone replacement therapy (HRT) in postmenopausal women suppresses the increase in bone resorption expected as circulating levels of endogenous estrogen decline. We tested the hypothesis that bone lead content might remain elevated in women on HRT. Fifty six women who at recruitment were on average 35 years postmenopausal were placed on calcium supplementation. Six months later 33 of these women were prescribed either low dose or moderate dose hormone replacement in addition to the calcium supplementation. After approximately 4 years of hormone replacement, lead content was measured at the tibia and calcaneus by in vivo fluorescence excitation, and lead concentrations were measured in serum, whole blood, and urine. Women not taking hormones had significantly lower lead concentrations in cortical bone compared to all women on HRT (p = 0.007). Tibia lead content (mean +/- SD) for women on calcium only was 11.13 +/- 6.22 microgram/g bone mineral. For women on HRT, tibia bone lead was 19.37 +/- 8.62 micrograms/g bone mineral on low-dose HRT and 16.87 +/- 11.68 micrograms/g bone mineral on moderate-dose HRT. There were no differences between groups for lead concentrations measured in trabecular bone, whole blood, serum or urine. Hormone replacement maintains cortical bone lead content. In women not on HRT, there will be a perimenopausal release of lead from bone.

FISH detection of Wolf-Hirschhorn syndrome: exclusion of D4F26 as critical site

Wolf-Hirschhorn syndrome (WHS) is due to a deletion in the terminal band of 4p16.3. Among loci that have been involved in deletions are D4S98, D4S95, D4S125, D4F26, as shown by PCR typing, Southern blot hybridization, and/or fluorescent in situ hybridization (FISH). Currently, FISH detection of WHS is predicted upon the deletion of the D4F26 locus with failure to hybridize to pC847.351, a commercially available cosmid probe. A WHS patient is shown to have an interstitial deletion, by hemizygosity at D4S98 and D4S95 but not at D4F26. This suggests that the tip of 4p, specifically D4F26, is not a critical deletion site for WHS.

Effects of 2 years of hormone replacement upon bone mass, serum lipids and lipoproteins

The objective of this study was to measure the effects on postmenopausal women of 2 years of either a low dose or a moderate dose regimen of hormone replacement upon bone mass and serum cardiovascular risk factors. After 6 months of calcium supplementation, 75 women chose to add hormone replacement or to remain on calcium. Those choosing hormones were randomised to either 0.3 mg/day equine estrogen and 2.5 mg/day medroxyprogesterone or 0.625 mg/day equine estrogen, days 1-25, and 5 mg/day medroxyprogesterone, days 16-25. On calcium only, lumbar spine bone mineral content and radius bone mass fell. Serum concentrations of cholesterol and triglycerides increased while HDL concentration fell. The low dose continuous regime reduced whole body bone turnover and prevented the age related reductions in bone mass and serum cardiovascular risk profile. The moderate dose regimen reduced whole body bone turnover and increased lumbar spine bone mass. Total serum cholesterol was unchanged while HDL levels increased, LDL levels fell and triglyceride concentration increased.

Prepubertal ovarian cyst formation: 5 years' experience

OBJECTIVE

To document the frequency of ovarian cyst formation in the prepubertal female and to report on the clinical implications of these cysts.

METHODS

We evaluated cases from a retrospective chart review of prepubertal females with ovarian cysts.

RESULTS

Over a 5-year period, 1818 ultrasound studies were completed in prepubertal females, from which 99 patients were identified as having ovarian cysts. The majority (82 of 99, 83%) were small, unilocular cysts averaging 2-3 mm in diameter. The incidence of these small cysts ranged at 2-5% in females between birth and age 8. Large ovarian cysts (ie, greater than 2 cm in diameter) are rare in young girls over age 2, with most occurring within the first year of life. Of the 17 large ovarian cysts, two presented with torsion and both were complex on ultrasound examination. Five (29%) of the large ovarian cysts were treated conservatively and demonstrated regression on follow-up; these were unilocular cysts. Although functioning cysts resulting in precocious pseudopuberty are expected to be rare, we identified five cases (5%) in our series.

CONCLUSIONS

Small, unilocular ovarian cysts less than 1 cm in diameter are found in prepubertal females with a frequency of 2-5% and are clinically insignificant. Ovarian cysts greater than 2 cm are rare. Unilocular ovarian cysts less than 5 cm may be followed conservatively with ultrasound surveillance until regression, without a major risk of torsion. Ovarian cysts associated with precocious pseudopuberty are generally larger than 2 cm and may be recurrent.

Measurement of heterophil antibody and antibodies to EB viral capsid antigen IgG and IgM in suspected cases of infectious mononucleosis

The EBV IgG titres in acute and convalescent specimens from 97 cases of infectious mononucleosis were compared with titres from acute and convalescent sera from 96 students with illnesses resembling infectious mononucleosis but without heterophil antibody, EB IgM or EB IgG seroconversion; and also with titres from 91 healthy students known to have had EB IgG antibody for at least six months. These titres were related to the titre of the Research Standard A.66/235 for infectious mononucleosis serum prepared by the National Institute for Biological Standards and Control. Serial sera were tested for heterophil antibody and EBVCA specific IgG and IgM from 61 university students with infectious mononucleosis. The period of persistence of heterophil antibody and EBV IgM after illness was outlined from the results of the tests. Single sera from 406 patients in hospital or general practice sent to the diagnostic laboratory for heterophil antibody tests were also tested for EBV antibodies without prior knowledge of the heterophil antibody result. The close agreement between heterophil antibody and EBV IgM results is shown. False positive EB IgM results were correlated with the presence of rheumatoid factor.

EB virus antibody and infectious mononucleosis in a boarding school for boys

A study of EB virus antibody was undertaken in a boarding school for boys between 11 and 18 years of age; 35% of boys had EBV antibody when first sampled and a small number acquired antibody each year. Some of these boys had had no recorded illness during the period before the first positive sample and some developed classic infectious mononucleosis which was accompainied by a positive heterophil antibody test and detection of EB virus specific IgM. In a school of 800 boys there were 13 cases of infectious mononucleosis in four years.

EB virus antibody at different ages

In relation to the study of infectious mononucleosis a survey of the prevalence of antibody to EB virus was made on the sera of persons of varying age from several different areas in England by the indirect immunofluorescence technique. About half those tested were found to have acquired antibody by the age of 4 years and there was a further significant increase in the proportion of those positive between the ages of 15 and 24 years. The finding of seroconversion in two patients who developed infectious mononucleosis provides further support for an association between EB virus and this condition.