Clinician perspectives of the implementation of an early intervention service for eating disorders in England: a mixed method study

BACKGROUND

The First Episode Rapid Early Intervention for Eating Disorders (FREED) service has been shown to reduce the wait for care and improve clinical outcomes in initial evaluations. These findings led to the national scaling of FREED in England. To support this scaling, we conducted a mixed method evaluation of the perceptions and experiences of clinicians in the early phases of scaling. The Normalisation Process Theory (NPT) was used as a conceptual lens to understand if and how FREED becomes embedded in routine practice.

METHODS

The convergent mixed method evaluation included 21 semi-structured interviews with clinicians from early adopter sites and 211 surveys administered to clinicians before, immediately after and 3 months after the FREED training. The interview guide and survey included questions evaluating attitudes towards early intervention for eating disorders (EDs) and NPT mechanisms. Interview data were analysed using an inductive thematic analysis. The NPT was applied to the inductively derived themes to evaluate if and how NPT domains impacted the implementation. Survey data were analysed using multilevel growth models.

RESULTS

Six themes and 15 subthemes captured barriers and facilitators to implementation at the patient, clinician, service, intervention, implementation and wider system levels. These interacted with the NPT mechanisms to facilitate or hinder the embedding of FREED. Overall, clinicians were enthusiastic and positive towards early intervention for EDs and FREED, largely because of the expectation of improved patient outcomes. This was a considerable driver in the uptake and implementation of FREED. Clinicians also had reservations about capacity and the potential impact on other patients, which, at times, was a barrier for its use. The FREED training led to significant improvements in positive attitudes and NPT mechanisms that were largely maintained at the 3-month follow-up. However, negative attitudes did not significantly improve following training.

CONCLUSIONS

Positive attitudes towards early intervention for EDs increased enthusiasm and engagement with the model. Features of the model and its implementation were effective at developing adopter commitment and capabilities. However, there were aspects of the model and its implementation which require attention in the future (e.g., capacity and the potential impact on the wider service).

National roll-out of early intervention for eating disorders: Process and clinical outcomes from first episode rapid early intervention for eating disorders

AIM

First Episode Rapid Early Intervention for Eating Disorders (FREED) is an early intervention model for young people with recent-onset eating disorders (ED). Promising results from a previous single-centre study and a four-centre study (FREED-Up) have led to the rapid national scaling of FREED to ED services in England (FREED-4-All). Our aim was to evaluate duration of an untreated ED (DUED), wait time target adherence, and clinical outcomes in FREED-4-All and compare these to the (benchmark) findings of the earlier FREED-Up study.

METHOD

FREED services submit de-identified data to the central FREED team quarterly. The current study covers the period between September 2018 and September 2021. This FREED-4-All dataset includes 2473 patients. These were compared to 278 patients from the FREED-Up study.

RESULTS

DUED was substantially shorter in the FREED-4-All dataset relative to the FREED-Up study (15 vs. 18 months). Adherence to the wait time targets was comparable in both cohorts (~85% of engagement calls attempted in <2 days, ~50%-60% of assessments offered in <14 days, ~40% of treatment offered in <28 days). Patients in the FREED-4-All dataset experienced significant improvements in ED and general psychological symptoms from pre- to post-treatment that were comparable to the FREED-Up study. These findings should be interpreted cautiously as only 6% of FREED-4-All patients had post-treatment data.

CONCLUSIONS

Data from the FREED-4-All evaluation suggest that FREED is replicating at scale. However, these data are flawed, uncertain, proximate, and sparse and should therefore be used carefully alongside other evidence and clinical experience to inform decision making.

The impact of the COVID-19 pandemic on referral numbers, diagnostic mix, and symptom severity in Eating Disorder Early Intervention Services in England

OBJECTIVE

First Episode Rapid Early Intervention for Eating Disorders (FREED) is a service model and care pathway which aims to provide timely, well-coordinated, developmentally informed and evidence-based care for young people with eating disorders (EDs). This article investigates the impact of the COVID-19 pandemic on FREED patient presentations and service provision in England.

METHOD

Data from three services spanning the pre- to post-pandemic period were included (January 2019-September 2021; n = 502 patients). Run charts were created to analyze changes in monthly baseline patient data (e.g., referral numbers, duration of an untreated ED, diagnostic mix, and average body mass index for patients with anorexia nervosa [AN]).

RESULTS

Significant increases in referral numbers were found from September 2020 onward, coinciding with the end of the first UK national lockdown. The percentage of AN presentations significantly increased after the onset of the first national lockdown (April 2020-December 2020). No other significant change patterns were identified.

DISCUSSION

There have been substantial increases in referral numbers and presentations of AN to FREED services whereas illness severity seems largely unchanged. Together, this suggests that increased referrals cannot be attributed to milder presentations being seen. Implications for the implementation, funding, and sustainability of the model are discussed.

PUBLIC SIGNIFICANCE

Our research suggests that early intervention eating disorder services across England faced significant increases in patient referrals and presentations of anorexia nervosa over the COVID-19 pandemic. This increase in referrals is not due to a rise in milder eating disorder cases, as baseline symptom severity remained stable across the pandemic. Investment in early intervention for eating disorders must therefore match increased referral trends.

Early weight gain trajectories in first episode anorexia: predictors of outcome for emerging adults in outpatient treatment

BACKGROUND

Early response to treatment has been shown to be a predictor of later clinical outcomes in eating disorders (EDs). Specifically, early weight gain trajectories in anorexia nervosa (AN) have been shown to predict higher rates of later remission in inpatient treatment. However, no study has, as of yet, examined this phenomenon within outpatient treatment of first episode cases of AN or in emerging adults.

METHODS

One hundred seven patients with AN, all between the ages of 16 and 25 and with an illness duration of < 3 years, received treatment via the first episode rapid early intervention in eating disorders (FREED) service pathway. Weight was recorded routinely across early treatment sessions and recovery outcomes (BMI > 18.5 kg/m2 and eating psychopathology) were assessed up to 1 year later. Early weight gain across the first 12 treatment sessions was investigated using latent growth mixture modelling to determine distinct classes of change. Follow-up clinical outcomes and remission rates were compared between classes, and individual and clinical characteristics at baseline (treatment start) were tested as potential predictors.

RESULTS

Four classes of early treatment trajectory were identified. Three of these classes (n = 95), though differing in their early change trajectories, showed substantial improvement in clinical outcomes at final follow-up. One smaller class (n = 12), characterised by a 'higher' start BMI (> 17) and no early weight gain, showed negligible improvement 1 year later. Of the three treatment responding groups, levels of purging, depression, and patient reported carer expressed emotion (in the form of high expectations and low tolerance of the patient) determined class membership, although these findings were not significant after correcting for multiple testing. A higher BMI at treatment start was not sufficient to predict optimal clinical outcomes.

CONCLUSION

First episode cases of AN treated via FREED fit into four distinct early response trajectory classes. These may represent subtypes of first episode AN patients. Three of these four trajectories included patients with substantial improvements 1 year later. For those in the non-response trajectory class, treatment adjustments or augmentations could be considered earlier, i.e., at treatment session 12.

Assessing implementation fidelity in the First Episode Rapid Early Intervention for Eating Disorders service model

BACKGROUND

The First Episode Rapid Early Intervention for Eating Disorders (FREED) service model is associated with significant reductions in wait times and improved clinical outcomes for emerging adults with recent-onset eating disorders. An understanding of how FREED is implemented is a necessary precondition to enable an attribution of these findings to key components of the model, namely the wait-time targets and care package.

AIMS

This study evaluated fidelity to the FREED service model during the multicentre FREED-Up study.

METHOD

Participants were 259 emerging adults (aged 16-25 years) with an eating disorder of <3 years duration, offered treatment through the FREED care pathway. Patient journey records documented patient care from screening to end of treatment. Adherence to wait-time targets (engagement call within 48 h, assessment within 2 weeks, treatment within 4 weeks) and care package, and differences in adherence across diagnosis and treatment group were examined.

RESULTS

There were significant increases (16-40%) in adherence to the wait-time targets following the introduction of FREED, irrespective of diagnosis. Receiving FREED under optimal conditions also increased adherence to the targets. Care package use differed by component and diagnosis. The most used care package activities were psychoeducation and dietary change. Attention to transitions was less well used.

CONCLUSIONS

This study provides an indication of adherence levels to key components of the FREED model. These adherence rates can tentatively be considered as clinically meaningful thresholds. Results highlight aspects of the model and its implementation that warrant future examination.

Acquisition of visual priors and induced hallucinations in chronic schizophrenia

Prominent theories suggest that symptoms of schizophrenia stem from learning deficiencies resulting in distorted internal models of the world. To test these theories further, we used a visual statistical learning task known to induce rapid implicit learning of the stimulus statistics. In this task, participants are presented with a field of coherently moving dots and are asked to report the presented direction of the dots (estimation task), and whether they saw any dots or not (detection task). Two of the directions were more frequently presented than the others. In controls, the implicit acquisition of the stimuli statistics influences their perception in two ways: (i) motion directions are perceived as being more similar to the most frequently presented directions than they really are (estimation biases); and (ii) in the absence of stimuli, participants sometimes report perceiving the most frequently presented directions (a form of hallucinations). Such behaviour is consistent with probabilistic inference, i.e. combining learnt perceptual priors with sensory evidence. We investigated whether patients with chronic, stable, treated schizophrenia (n = 20) differ from controls (n = 23) in the acquisition of the perceptual priors and/or their influence on perception. We found that although patients were slower than controls, they showed comparable acquisition of perceptual priors, approximating the stimulus statistics. This suggests that patients have no statistical learning deficits in our task. This may reflect our patients' relative wellbeing on antipsychotic medication. Intriguingly, however, patients experienced significantly fewer (P = 0.016) hallucinations of the most frequently presented directions than controls when the stimulus was absent or when it was very weak (prior-based lapse estimations). This suggests that prior expectations had less influence on patients' perception than on controls when stimuli were absent or below perceptual threshold.

Gene expression and linkage analysis implicate CBLB as a mediator of rituximab resistance

Elucidating resistance mechanisms for therapeutic monoclonal antibodies (MAbs) is challenging, because they are difficult to study in non-human models. We therefore developed a strategy to genetically map in vitro drug sensitivity, identifying genes that alter responsiveness to rituximab, a therapeutic anti-CD20 MAb that provides significant benefit to patients with B-cell malignancies. We discovered novel loci with genome-wide mapping analyses and functionally validated one of these genes, CBLB, which causes rituximab resistance when knocked down in lymphoma cells. This study demonstrates the utility of genome-wide mapping to discover novel biological mechanisms of potential clinical advantage.

Reading between the lines: molecular characterization of five widely used canine lymphoid tumour cell lines

Molecular characterization of tumour cell lines is increasingly regarded as a prerequisite for defining their validity as models of in vivo neoplasia. We present the first comprehensive catalogue of genomic and transcriptional characteristics of five widely used canine lymphoid tumour cell lines. High-resolution microarray-based comparative genomic hybridization defined their unique profiles of genomic DNA copy number imbalance. Multicolour fluorescence in situ hybridization identified aberrant gains of MYC, KIT and FLT3 and deletions of PTEN and CDKN2 in individual cell lines, and also revealed examples of extensive structural chromosome reorganization. Gene expression profiling and RT-PCR analyses defined the relationship between genomic imbalance and transcriptional dysregulation in each cell line, clarifying their relevance as models of discrete functional pathways with biological and therapeutic significance. In combination, these data provide an extensive resource of molecular data for directing the appropriate use of these cell lines as tools for studying canine lymphoid neoplasia.

Generalized epilepsy with febrile seizures plus-associated sodium channel beta1 subunit mutations severely reduce beta subunit-mediated modulation of sodium channel function

Two novel mutations (R85C and R85H) on the extracellular immunoglobulin-like domain of the sodium channel beta1 subunit have been identified in individuals from two families with generalized epilepsy with febrile seizures plus (GEFS+). The functional consequences of these two mutations were determined by co-expression of the human brain NaV1.2 alpha subunit with wild type or mutant beta1 subunits in human embryonic kidney (HEK)-293T cells. Patch clamp studies confirmed the regulatory role of beta1 in that relative to NaV1.2 alone the NaV1.2+beta1 currents had right-shifted voltage dependence of activation, fast and slow inactivation and reduced use dependence. In addition, the NaV1.2+beta1 current entered fast inactivation slightly faster than NaV1.2 channels alone. The beta1(R85C) subunit appears to be a complete loss of function in that none of the modulating effects of the wild type beta1 were observed when it was co-expressed with NaV1.2. Interestingly, the beta1(R85H) subunit also failed to modulate fast kinetics, however, it shifted the voltage dependence of steady state slow inactivation in the same way as the wild type beta1 subunit. Immunohistochemical studies revealed cell surface expression of the wild type beta1 subunit and undetectable levels of cell surface expression for both mutants. The functional studies suggest association of the beta1(R85H) subunit with the alpha subunit where its influence is limited to modulating steady state slow inactivation. In summary, the mutant beta1 subunits essentially fail to modulate alpha subunits which could increase neuronal excitability and underlie GEFS+ pathogenesis.

Structure-function relationships in yeast tubulins

A comprehensive set of clustered charged-to-alanine mutations was generated that systematically alter TUB1, the major alpha-tubulin gene of Saccharomyces cerevisiae. A variety of phenotypes were observed, including supersensitivity and resistance to the microtubule-destabilizing drug benomyl, lethality, and cold- and temperature-sensitive lethality. Many of the most benomyl-sensitive tub1 alleles were synthetically lethal in combination with tub3Delta, supporting the idea that benomyl supersensitivity is a rough measure of microtubule instability and/or insufficiency in the amount of alpha-tubulin. The systematic tub1 mutations were placed, along with the comparable set of tub2 mutations previously described, onto a model of the yeast alpha-beta-tubulin dimer based on the three-dimensional structure of bovine tubulin. The modeling revealed a potential site for binding of benomyl in the core of beta-tubulin. Residues whose mutation causes cold sensitivity were concentrated at the lateral and longitudinal interfaces between adjacent subunits. Residues that affect binding of the microtubule-binding protein Bim1p form a large patch across the exterior-facing surface of alpha-tubulin in the model. Finally, the positions of the mutations suggest that proximity to the alpha-beta interface may account for the finding of synthetic lethality of five viable tub1 alleles with the benomyl-resistant but otherwise entirely viable tub2-201 allele.

VH4-34 encoded antibodies in systemic lupus erythematosus: a specific diagnostic marker that correlates with clinical disease characteristics

OBJECTIVE

To determine the clinical significance of elevated serum levels of VH4-34 encoded antibodies (VH4-34 Ab) with respect to the diagnosis and clinical characteristics of systemic lupus erythematosus (SLE).

METHODS

Ninety-five patients with SLE and 344 controls were studied. The controls included 34 healthy individuals, 282 patients with nonautoimmune diseases, and 28 patients with autoimmune diseases other than SLE. VH4-34 Ab levels were measured by inhibition ELISA using anti-idiotope monoclonal antibody (9G4). SLE disease activity, severity, and damage were assessed by visual analog scales, Systemic Lupus Activity Measure, Lupus Severity of Disease Index, and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index.

RESULTS

Fifty-two of 95 patients with SLE had elevated levels of VH4-34 Ab compared to 18 of 344 controls (5%), giving a sensitivity of 55% and a specificity of 95% for elevated VH4-34 Ab as a serologic test for SLE. The positive predictive value of elevated VH4-34 under these conditions was 74-85%. In this study, anti-dsDNA was not VH4-34 encoded. Significant correlations between VH4-34 and disease activity and severity indices were observed (r = 0.29-0.50). The relative risk for severe disease in SLE patients with VH4-34 antibody level in the highest tertile compared to the lowest tertile was 5.25. Twenty-five of 29 patients with lupus nephritis and 6 of 6 patients with central nervous system (CNS) lupus had elevated VH4-34 Ab.

CONCLUSION

With a specificity of 94-95%, the VH4-34 antibody assay may prove valuable as a confirmatory diagnostic test for SLE. In patients with known SLE, serum VH4-34 Ab levels correlate with overall disease severity and activity, but not damage, and with nephritis and CNS lupus.

Molecular definition of the retention parameters of peptides separated by RP-HPLC

Different physicochemical properties of the constituent amino acid side chains have been employed in order to investigate the molecular basis of the experimentally derived retention parameters, S and log k0, of peptides separated by reversed-phase high performance liquid chromatography (RP-HPLC). The results demonstrate that the S-value is strongly related to the total surface area of a peptide but correlates poorly with the corresponding predicted hydrophobicity based on the summated amino acid group retention coefficients. In contrast, the experimentally derived log k0 value correlates well with both the total surface area and the predicted affinity values derived from the incremental free energy of transfer calculated from the summated amino acid retention coefficients. Since the S and log k0 values are parameters useful to the interpretation of peptide and protein chromatographic behavior in RP-HPLC, the results of the present study document the physicochemical relationships that exist between these retention parameters and peptide structure.

RPB7, one of two dissociable subunits of yeast RNA polymerase II, is essential for cell viability

The Saccharomyces cerevisiae RNA polymerase II subunit gene RPB7 was isolated and sequenced. RPB7 is a single copy gene whose sequence predicts a 19,000 Dalton protein of 171 amino acids. RPB7 is known to dissociate from RNA polymerase II as an RPB4/RPB7 subcomplex in vitro. RPB7 also appears to interact with RNA polymerase II in a manner dependent upon RPB4, since RNA polymerase II purified from cells lacking RPB4 also lacks RPB7. Previous results have demonstrated that deletion of the RPB4 results in slow growth and cold- and temperature-sensitivity. In contrast, deletion of the RPB7 gene revealed that it is essential for cell growth and viability. Loss of both the RPB4 and the RPB7 genes causes lethality. These results suggest that RPB7 contributes to the function of RNA polymerase II in the absence of RPB4 either in a manner independent of its association with the enzyme or by directly binding to the enzyme in a manner independent of its association with RPB4.

Assessment of aortic and pulmonic stenosis by echocardiography

Doppler and imaging echocardiography are highly useful methods of identifying and quantifying both aortic and pulmonic stenosis. The presence of valve stenosis and associated regurgitation is based on detecting abnormal intracardiac velocity patterns near the affected valve. Defining the specific valve involved and the type of lesion present is based on determining the location and timing of the abnormal velocities. Both color flow imaging and duplex pulsed Doppler with two-dimensional echocardiographic imaging are highly accurate in identifying the lesions present. Quantification of the severity of stenotic lesions requires calculation of the pressure gradient across the valve and estimation of valve area; quantification of volume flow rate is frequently helpful. The pressure gradient is calculated from high velocity data acquired in the stenotic valve orifice by using the Bernoulli equation. Volume flow rate through the valve can be estimated by using Doppler velocity data and two-dimensional echocardiographic imaging data acquired at sites upstream from the stenotic valve. The continuity equation allows calculation of valve area that is based on this noninvasive stroke volume and pressure gradient data. This review characterizes flow patterns present near stenotic valves, discusses the equations required to quantify aortic and pulmonic stenosis, and then describes the clinical approach to the noninvasive quantification of both stenotic lesions.

Engineering the chloroplast genome: techniques and capabilities for chloroplast transformation in Chlamydomonas reinhardtii

Chloroplast transformation of Chlamydomonas reinhardtii has been accomplished by agitating cell wall-deficient cells in the presence of glass beads and DNA. By using the atpB gene as the selected marker and cells grown in 0.5 mM 5-fluorodeoxyuridine, we have recovered up to 50 transformants per microgram of DNA. This method is easy and does not require specialized equipment, although it is not as efficient as the tungsten particle bombardment method [Boynton, J. E., Gillham, N. W., Harris, E. H., Hosler, J. P., Johnson, A. M., Jones, A. R., Randolph-Anderson, B. L., Robertson, D., Klein, T. M., Shark, K. B. & Sanford, J. C. (1988) Science 240, 1534-1537]. By using particle bombardment, we have developed a cotransformation approach in which spectinomycin-resistant 16S rRNA-encoding DNA is the selected marker, and we have demonstrated that cotransformation of an unselected marker on an independent replicon is very efficient. We have used this strategy (i) to recover transformants with partially deleted atpB genes that could not otherwise have been selected since they did not restore photosynthetic capability to a recipient carrying a more extensive atpB deletion and (ii) to generate specific deletion mutations in a wild-type recipient. This methodology should allow the introduction of any desired change into the chloroplast genome, even in the absence of phenotypic selection, and thus a detailed functional analysis of any chloroplast DNA sequence should be possible.

Accuracy of mitral Doppler echocardiographic cardiac output determinations in adults

The Doppler echocardiographic estimation of cardiac output at the mitral valve site is often underestimated in adults with slow heart rates because the mitral valve remains open in mid-diastole when flow is markedly reduced. Therefore we tested several approaches to this measurement in 17 adults with nonvalvular heart disease who had thermodilution catheters in the right side of the heart. Superior correlations with thermal output values were obtained by a new method that excludes mitral orifice measurements during mid-diastole when flow less than 10 cm/sec (r = 0.94) compared with the standard method (r = 0.89). Also, the new method resulted in significantly less underestimation of thermal cardiac output in patients with heart rates less than 70 beats/min (-10%) compared with the standard method (-34%). In addition, use of a constant maximal two-dimensional echocardiographic mitral orifice correction factor of 0.77 with the new method to account for variations in mitral valve orifice during the cardiac cycle, as opposed to 0.68 with the standard method, resulted in similar results as compared with determining individual correction factors from M-mode echoes. We conclude that: (1) the mitral orifice approach is accurate for measuring cardiac output in adult patients with nonvalvular heart disease; (2) a new method that excludes mid-diastolic mitral orifice measurements is superior to the standard method; and (3) use of a constant two-dimensional echocardiographic mitral valve orifice correction factor obviates the need for M-mode echoes.

Identification of an IgA inhibitor of neutrophil chemotaxis and its membrane target for the metabolic burst

Affinity-purified IgA from the serum of an 8-year-old boy with a 5-year history of recurrent facial nodules, intermittent neutropenia and elevated immunoglobulin levels, inhibited the chemotaxis of polymorphonuclear neutrophils (PMN) from both patient and normal adults. Preincubation of normal PMN with IgA from the patient's serum (0.5 mg/ml) inhibited chemotaxis to C5a and to the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP) by 80%, while IgA or IgG from pooled human serum and IgG from the patient were without effect. Normal PMN chemotaxis was restored after IgA depletion of the patient's serum by affinity chromatography. The patient's IgA, but not IgA from pooled human serum, bound specifically to normal PMN by its antigen-binding sites and recognized a 62,000 MW membrane protein on normal neutrophils, which was distinct from the FMLP receptor, the C5a receptor, or the Fca receptor. Attachment of the patient's IgA to the 62,000 MW protein activated intracellular oxidative metabolism on a parity with phorbol myristate acetate (PMA) and resulted in a significant up-regulation of membrane receptors for FMLP. After the binding of patient (Pt) IgA, normal neutrophils were rendered significantly less responsive to subsequent stimulation with phorbol esters. These results characterize a novel mechanism of chemotactic inhibition by serum IgA and also identify a neutrophil membrane protein that is linked to intracellular oxidative metabolism.

Inadequacy of the Gorlin formula for predicting prosthetic valve area

A total of 135 patients with normally functioning prosthetic aortic valves who were catheterized 6 months after placement of Hancock, modified Hancock or Bjork-Shiley prostheses were studied to determine the magnitude of error in Gorlin formula estimates of prosthetic aortic valve area. All patients were male, selected from 13 participating hospitals and routinely followed after valve replacement for 5 years. Hemodynamically determined Gorlin valve areas were compared with independently verified actual valve areas. Actual Hancock areas were measured from videotapes of valves exercised in a pulse duplicator flow model. Actual Bjork-Shiley areas were calculated directly from the valves' inner ring radius. Gorlin valve areas correlated poorly with actual valve areas (r = 0.39). The mean Gorlin formula error was 0.36 cm2 (standard deviation = 0.32). Gorlin areas overestimated actual areas by greater than 0.25 cm2 in 43 patients (32%) and underestimated actual areas by greater than 0.25 cm2 in 29 (21%). It was concluded that the Gorlin formula inaccurately predicts prosthetic valve area in the aortic position. Overreliance on this formula in assessing aortic stenosis could lead to errant clinical decisions.

Mitral valve prolapse in patients with prior rheumatic fever

It is known that rheumatic heart disease frequently results in isolated mitral regurgitation without concomitant mitral stenosis, especially in countries with a high prevalence of rheumatic fever. However, more recent surgical pathologic data also have demonstrated a high incidence of mitral valve prolapse in cases of rheumatic heart disease, which suggests that rheumatic fever may be a cause of mitral valve prolapse. To determine whether this association of mitral valve prolapse and rheumatic heart disease is present in a stable clinic population, we studied 30 patients who had an apical systolic murmur and a well-documented history of rheumatic fever with dynamic auscultation, two-dimensional echocardiography, and pulsed Doppler examinations. Twenty of the 30 patients (67%) had findings on physical examination consistent with isolated mitral regurgitation and 25 patients (84%) had mitral regurgitation by Doppler examination. Echocardiography demonstrated mitral valve prolapse in 24 patients (80%), whereas only one of the total study group had echocardiographic findings consistent with mitral stenosis. We conclude that (1) the presence of an isolated systolic murmur in patients with a history of rheumatic fever frequently represents pure mitral regurgitation secondary to mitral valve prolapse and (2) postinflammatory changes in valvular tissue resulting from rheumatic fever may be the etiology of mitral valve prolapse in these patients.

Differing mechanisms of exercise flow augmentation at the mitral and aortic valves

To determine the mechanisms by which blood flow increases across the mitral and aortic valves during exercise, 18 normal men were studied during graded supine and upright bicycle exercise at matched workloads. Mitral valve orifice and ascending aortic blood velocities were recorded by Doppler echocardiography during steady states at each stage of exercise. Parasternal two-dimensional echocardiographic imaging of the ascending aorta adjacent to the aortic valve orifice and the mitral valve orifice at the tips of the valve leaflets was used to calculate changes in cross-sectional area during exercise. Heart rate increased from rest to exercise from 67 to 150 beats/min (124%) during supine exercise and from 72 to 147 beats/min (104%) during upright exercise. Stroke volume increased 20% during supine and 46% during upright exercise; the increase in stroke volume was statistically significant when rest and exercise were compared and when the magnitude of change was compared vs position (p less than .05). The increase in stroke volume measured at the ascending aorta was accomplished by an increase in the velocity-time integral (+15% supine and +48% upright, p less than .05), with little change in aortic cross-sectional area (5% supine and 0% upright, p = NS). By contrast, the increase in flow rate measured at the mitral valve was predominantly due to an increase in mean diastolic cross-sectional area (+29% supine and 34% upright, p less than .05); the velocity-time integral did not increase significantly (-10% supine and 4% upright; p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Calculation of aortic valve area by Doppler echocardiography: a direct application of the continuity equation

The continuity equation suggests that a ratio of velocities at two different cardiac valves is inversely proportional to the ratio of cross-sectional areas of the valves. To determine whether a ratio of mitral/aortic valve orifice velocities is useful in determining aortic valve area in patients with aortic stenosis, 10 control subjects and 22 patients with predominant aortic stenosis were examined by Doppler echocardiography. The ratio of (mean diastolic mitral velocity)/(mean systolic aortic velocity), (Vm)/(Va), and the ratio of (mitral diastolic velocity-time integral)/(aortic systolic velocity-time integral), (VTm)/(VTa), were determined from Doppler spectral recordings. Aortic valve area determined at catheterization by the Gorlin equation was the standard of reference. High-quality Doppler recordings were obtained in 30 of 32 subjects (94%). Catheterization documented valve areas of 0.5 to 2.6 (mean 1.1) cm2. There was good correlation between Doppler-determined (Vm)/(Va) and Gorlin valve area (r = .90, SEE = 0.23 cm2); a better correlation was noted between (VTm)/(VTa) and Gorlin valve area (r = .93, SEE = 0.18 cm2). The data demonstrate the usefulness of Doppler alone in the determination of aortic valve area in adults with absent or mild aortic or mitral regurgitation and no mitral stenosis. Although the use of mean velocity and velocity-time integral ratios requires accurate measurement of mitral and aortic velocities, it does not require squaring of these velocities or measurement of the cross-sectional area of flow.

Hydraulic estimation of stenotic orifice area: a correction of the Gorlin formula

To determine the source of errors in the Gorlin formula for estimating stenotic valvular orifice area, we used a pulsatile flow model that emulated left ventricular and aortic pressures and flow and allowed control of ventricular outflow orifice area. After comparing orifice areas calculated by the Gorlin formula with actual orifice areas, the Gorlin formula constant (k) was found to be highly correlated with the square root of the mean transvalvular gradient (r = .95). A new formula was derived empirically and predicted areas more accurately and with smaller standard errors than the Gorlin formula in the model (r = .98, SEE = 0.11 and r = .87, SEE = 0.28, respectively) in a series of 19 patients with Hancock porcine xenograft valves (r = .89, SEE = 0.07 and r = .60, SEE = 0.12, respectively) and in the original series of patients reported by Gorlin and Gorlin in proposing the Gorlin formula (r = .93, SEE = 0.11 and r = .91, SEE = 0.12, respectively).

Doppler echocardiographic diagnosis and quantification of valvular heart disease

Doppler echocardiography is a logical companion to ultrasound imaging in the diagnosis and quantification of valvular heart disease. Accurate noninvasive identification and quantification of valvular heart disease is now possible if both techniques are utilized together. The continued application of our knowledge of hemodynamics should extend our current uses of Doppler echocardiography to allow more intelligent management of patients with known or suspected valvular heart disease.

Comparison of Doppler echocardiographic peak frequency and turbulence parameters in the quantification of aortic stenosis in a pulsatile flow model

To test the relative accuracy of Doppler echocardiographic peak frequency and turbulence parameters in assessing aortic stenosis, we constructed a pulsatile flow model that simulated human left ventricular and aortic pressures, flow, and anatomy. Continuous wave-measured peak frequencies and pulsed Doppler-measured turbulence were determined in the model ascending aorta for nine stenotic valve areas for each of five different flow rates. The mean squared systolic peak frequency (MSPF) and turbulence spectral envelope area (SEA) were regressed against the mean systolic gradient (r = .94, SEE = 5.6 mm Hg; and r = .96, SEE = 1.2 mm Hg, respectively). SEA was more accurate than MSPF at moderate-to-high degrees of stenosis and exhibited a smaller standard error. MSPF was more accurate than SEA in mild stenoses, where SEA tended to overestimate gradients. When flow data were included in a multiple regression analysis, both MSPF and SEA provided fair predictions of actual effective valve areas (r = .90 and r = .94, respectively). Use of high pulse-repetition-frequency Doppler echocardiography significantly reduced aliasing problems common to pulsed Doppler techniques.

Usefulness of the postexercise response of systolic blood pressure in the diagnosis of coronary artery disease

The normal decline in systolic blood pressure (SBP) during the recovery phase of treadmill exercise does not occur in some patients with coronary artery disease (CAD). In others the recovery values of SBP exceed the peak exercise values. To examine the diagnostic value of this observation, we studied 31 normal subjects and 56 patients undergoing treadmill exercise before coronary cineangiography. Because of large differences in peak exercise pressures between the two groups, recovery ratios were derived by dividing the SBP at 1, 2, and 3 min after exercise by the peak exercise SBP. The 1, 2, and 3 min ratios in the normal subjects declined steadily from 0.85 +/- 0.07 (SD) to 0.79 +/- 0.06 and to 0.73 +/- 0.06, respectively, while the ratios in the patients with CAD remained elevated at 0.97 +/- 0.12 to 0.97 +/- 0.11 to 0.93 +/- 0.13. With use of the upper limits defined by two SDs of the normal value, recovery ratios were compared with the occurrence of angina and with ST segment depression on the exercise electrocardiogram in the patients with CAD. Abnormal ratios were more frequent in patients with CAD (53/56, 95%) than in those with ST segment depression (33/56, 59%), angina (37/56, 66%), and either ST segment depression or angina (42/56, 75%). Twenty of the patients with CAD who were on no medication underwent an additional treadmill exercise test on a separate day and no significant differences were found in the ratios from the two tests. Ten additional patients with CAD underwent treadmill exercise testing while on placebo and while on a beta-blocker.(ABSTRACT TRUNCATED AT 250 WORDS)

Diastolic coronary artery pressure-flow velocity relationships in conscious man

We characterised the diastolic pressure-flow velocity relationship in the normal left coronary artery of conscious man before and after vasodilatation with angiographic contrast medium. Phasic coronary artery pressure and flow velocity were measured in ten patients during individual diastoles (0.5 to 1.0 s) using a 20 MHz catheter-tipped, pulsed Doppler transducer. All pressure-flow velocity curves were linear over the diastolic pressure range of 110 +/- 15 (SD) mmHg to 71 +/- 7 mmHg (r = 0.97 +/- 0.01). In the basal state, values for slope and extrapolated zero flow pressure intercept averaged 0.35 +/- 0.12 cm X s-1 X mmHg-1 and 51.7 +/- 8.6 mmHg, respectively. Vasodilatation resulted in a 2.5 +/- 0.5 fold increase in mean flow velocity. The diastolic pressure-flow velocity relationship obtained during peak vasodilatation compared to that during basal conditions was characterised by a steeper slope (0.80 +/- 0.48 cm X s-1 X mmHg-1, p less than 0.001) and lower extrapolated zero flow pressure intercept (37.9 +/- 9.8 mmHg, p less than 0.05). Mean right atrial pressure for the group averaged 4.4 +/- 1.7 mmHg, while left ventricular end-diastolic pressure averaged 8.7 +/- 2.8 mmHg. These observations in man are similar to data reported in the canine coronary circulation which are consistent with a vascular waterfall model of diastolic flow regulation. In this model, coronary blood flow may be regulated by changes in diastolic zero flow pressure as well as in coronary resistance.

Positive inotropic and vasodilator effects of MDL 17,043 in patients with reduced left ventricular performance

To assess the potential positive inotropic properties of the drug MDL 17,043, 10 patients were studied who had impaired left ventricular (LV) performance and who were undergoing diagnostic cardiac catheterization (LV ejection fraction 16 to 46%). MDL 17,043 was given in repeated i.v. doses of 0.5 mg/kg every 15 minutes until a maximal effect was observed or a total dose of 3 mg/kg was attained. Cardiac output increased from 3.5 +/- 1.0 to 5.3 +/- 0.7 liters/min (p less than 0.005); pulmonary artery wedge pressure decreased from 22 +/- 4 to 9 +/- 5 mm Hg (p less than 0.001); and total systemic resistance decreased from 2,335 +/- 1,147 to 1,310 +/- 365 dyne cm-5 (p less than 0.025). Also, maximal LV dP/dt increased from 1,011 +/- 301 to 1,243 +/- 330 mm Hg/s (p less than 0.001). No significant changes in heart rate, systemic blood pressure, routine blood chemistries, complete blood counts or platelet counts were observed. Thus, MDL 17,043 has hemodynamic effects consistent with positive inotropic and vasodilating properties in patients with reduced LV performance. Because this agent is effective orally, further evaluation in patients with overt congestive heart failure is warranted.

A modified microchamber method for chemotaxis and chemokinesis

A 48 well chemotaxis microchamber, originally designed for use with polycarbonate filters, was used with nitrocellulose filters to quantitate chemotaxis and chemokinesis of granulocytes. Various features of the microchamber were compared to Boyden chambers. The accuracy and reproducibility of the method were found to be comparable to Boyden chambers in the variability between individual readings and superior in the variability between replicate values. Concentrations of optimal doses of chemoattractant for chemotaxis and chemokinesis were similar using both types of chamber. The data indicates that this method may be useful in studying components of the chemotactic response which require the use of cellulose filters. Advantages of this method over standard Boyden chambers include the use of a single filter rather than individual, non-identical filters and a reduction in the number of cells required, particularly for pediatric testing or in neutropenic patients.

Alterations of the glycocalyx of Fc receptor-bearing cell lines during Fc receptor-ligand interactions

The binding of IgG-coated erythrocytes to Fc receptors on both a lymphoblastoid and a macrophage-like cell line resulted in a decrease in thickness of the polyanionic, extracellular glycocalyx (cell coat) as determined by electron microscopic histochemistry. This decrease showed no correlation with ligand-binding sites and was considered to be a generalized extramembrane effect. Pretreatment of the cells with trypsin or neuraminidase produced decreases in thickness similar to those observed following ligand binding. The results suggest a possible role for enzymatic cleavage of extracellular constituents by morphologically and functionally different cell types and may represent an event common to cell-surface recognition.

Noninvasive diagnosis of aortic and mitral valve disease with pulsed-Doppler spectral analysis

To differentiate normal from abnormal left-sided heart valves, 34 adults (6 normal and 28 abnormal) with 48 valve lesions proved at catheterization were examined using a 3 MHz duplex pulsed Doppler echocardiograph with 2-dimensional verification of sample volume position and on-line display of the Doppler audio spectrum. A uniform protocol was used to position the sample volume for each lesion and to analyze the Doppler spectral data. Intracardiac blood turbulence, manifested by an increased Doppler spectral envelope area, was the noninvasive indicator of disease. The specific lesion present was determined by documenting the intracardiac location and timing of the turbulence. Doppler spectral envelope areas in all normal valve sites were smaller than those measured at the same sites in patients with aortic stenosis, mitral stenosis, and mitral regurgitation (p less than 0.01). Except for a single patient with minimal aortic regurgitation, spectral envelope area allowed complete separation of patients with valve disease from normal subjects (p less than 0.01). High sensitivity (97%) and specificity (100%) were noted despite the presence of multiple valve lesions in 67% of the patients. The data demonstrate application of a simple, noninvasive method of acquiring and analyzing Doppler echocardiographic data which allows accurate identification or exclusion of left-sided valve disease in adults, even in the presence of multiple valve lesions.

Angioplasty catheter communication mimicking coronary arterial dissection

We report a case in which a sudden communication between the pressure and balloon inflation lumens of a percutaneous transluminal angioplasty (PTCA) catheter angiographically mimicked dissection of the coronary artery. This case illustrates a previously undescribed catheter artifact that must be differentiated from other complications of PTCA.

Digital Fourier techniques in the diagnosis and quantification of aortic stenosis with pulsed-Doppler echocardiography

Pulsed Doppler echocardiography and digital Fourier analysis were utilized to examine flow distal to the aortic valve and to quantify aortic stenosis. A graphic index of parameters derived from velocity spectrum patterns generated by Fourier analysis was regressed against mean systolic pressure gradients in 21 adults with clinical evidence of aortic stenosis who underwent catheterization studies and five normal adults (r = .82). Correlation improved in the absence of regurgitation (r = .92). Sensitivity for detecting gradients greater than 30 mmHg was 86%; specificity was 90%. Doppler spectral analysis shows promise in alleviating the need for many invasive studies.

Predictive value of early postmyocardial infarction modified treadmill exercise testing in multivessel coronary artery disease detection

We evaluated 57 patients with modified treadmill exercise testing and angiography early post-infarction (MI) to determine the predictive value of ST segment depression, angina, and an inadequate blood pressure response for multivessel coronary artery disease (MVCAD). ST segment depression alone identified MVCAD stenoses (greater than or equal to 70% diameter narrowing in two or more vessels) with sensitivity 54%, specificity 75%, and accuracy 60%. When ST segment depression and angina were considered a positive treadmill test result, a significant improvement in sensitivity (88%, p less than 0.01) and accuracy (82%, p less than 0.05) for MVCAD was observed. An inadequate blood pressure response was associated with MVCAD (12 of 13 patients) and a significantly reduced average left ventricular (LV) ejection fraction of 39 plus or minus 13% compared to 58 plus or minus 14% for patients without this treadmill abnormality (p less than 0.01). Therefore, we conclude that (1) ST segment depression and angina on early post-MI modified treadmill exercise testing are superior predictors of MVCAD compared to ST segment depression alone and (2) an inadequate blood pressure response during modified exercise testing early following MI is observed in patients with MVCAD and reduced LV performance.

Immunoglobulin E anti-Staphylococcus aureus antibodies in atopic patients

Sera from 56 patient and normal adults were examined to quantitate total immunoglobulin E (IgE) and IgE antibodies to Staphylococcus aureus and Staphylococcus epidermidis. Patients were divided into six groups based on clinical symptoms; a seventh group consisted of normal adults. Anti-S, aureus IgE binding was significantly higher in three groups of patients (those with eczema, those with or without series staphylococcal abscesses, and allergic patients with staphylococcal skin infections) than it was in the control group. Patients with high IgE due to allergies or parasitic infections without staphylococcal infections and patients with low or normal IgE and serious staphylococcal infection showed low levels of binding. The assay measured specific binding of IgE to bacterial antigens.

Prevention of contrast-induced bradycardia during coronary angiography

A double-blind study of 90 patients undergoing coronary angiography was performed to determine the safety and efficacy of 0.6 mg atropine sulfate in preventing contrast-induced bradycardia. Coronary angiography performed using the Sones technique resulted in ventricular pauses of greater than 2 seconds in 3 of 49 patients (6%) who received prophylactic atropine and 20 of 41 patients (49%) receiving placebo. Though the pauses were usually due to atrial asystole, 26% of those with greater than 2 second pauses did so because of transient complete heart block. Prophylactic atropine did increase resting heart rate but did not cause other arrhythmias or increase the frequency of angina pectoris despite the presence of severe coronary disease. Our data indicate that contrast-induced asystole is very common, cannot be predicted by consideration of "precatheterization data," and can be prevented effectively and safely by use of prophylactic atropine sulfate.

Venous thromboembolism in decompensated chronic obstructive pulmonary disease. A prospective study

Largely on the basis of postmortem studies, pulmonary emboli have been implicated as an etiologic factor in the acute and chronic respiratory failure of chronic obstructive pulmonary disease (COPD). The diagnosis of pulmonary embolism clinically or by tests directed at the lungs (except pulmonary angiography) is likely to be inaccurate in the presence of COPD because of the underlying abnormalities. We reasoned that by directing tests at the lower extremities to determine the presence or absence of deep venous thrombosis (DVT), we might obtain an accurate reflection of the presence of pulmonary emboli (PE), since virtually all PE are believed to arise in those deep veins. Accordingly, in a group of 45 patients with decompensated COPD, we performed ascending contrast venography (12 patients), 125I-labeled fibrinogen scanning (6 patients), or both (27 patients). Only 2 patients had proximal DVT, which was probably present on admission (4.4%). Two other patients developed DVT (limited to the calf) while hospitalized, (overall incidence of 8.9%). Another patient developed superficial thrombophlebitis during the study but before venography. Noninvasive tests for DVT (Doppler ultrasound and impedance plethysmography) were performed in 40 subjects. A negative result had a high predictive value (94% for each), but contrary to findings in other settings, a positive test had a poor predictive value (Doppler = 33%, IPG = 25%).

131I-labeled fibrinogen in the diagnosis of deep vein thrombosis of the lower extremities

Autologous 131I-labeled fibrinogen was administered to 17 patients during 19 episodes of suspected lower extremity deep vein thrombosis in an attempt to assess its diagnostic accuracy. Serial rectilinear scanning and probe counting of the lower extremities and pelvis were performed and compared with ascending contrast venography. The sensitivities of imaging and counting were 67% and 47%, respectively, and both had a specificity of 95%. The experience with evaluation of deep vein thrombosis of the pelvic and iliac veins was small but suggested that 131I fibrinogen will be of limited use in those vessels.

Noninvasive diagnosis of deep venous thrombosis

Eighty-five patients suspected of having lower-extremity deep venous thrombosis (DVT) participated in a prospective study to test the diagnostic accuracy of four noninvasive techniques: Doppler ultrasonic flow study, electrical impedance plethysmography, the serial dilution protamine sulfate test, and an extensive physical examination. Ascending radiocontrast phlebography was the diagnostic standard of reference. We found that (1) when both Doppler and impedance examinations were positive, the diagnosis of DVT could be considered virtually certain; (2) impedance and Doppler examinations, when used in combination, were reliable screening tests capable of establishing or excluding the presence of thigh DVT; (3) physical examination and the serial dilution protamine sulfate test were unreliable screening techniques for DVT; (4) techniques other than the noninvasive methods investigated were needed to reliably detect or to exclude popliteal and call DVT.