Heart rate variability enhances the prognostic value of established parameters in patients with congestive heart failure.

This prospective study evaluated whether heart rate variability (HRV) assessed from Holter ECG has prognostic value in addition to established parameters in patients with congestive heart failure (CHF). The study included 222 patients with CHF due to dilated or ischemic cardiomyopathy (left ventricular ejection fraction LVEF 21+/-1%; mean+/-SEM). During a mean follow-up of 15+/-1 months, 38 (17%) patients died and 45 (20%) were hospitalized due to worsening of CHF. The HRV parameter SDNN (standard deviation of all intervals between normal beats) was significantly lower in non-surviving or hospitalized than in event-free patients (118+/-6 vs 142+/-5 ms), as were LVEF (18+/-1 vs 23+/-1%), and peak oxygen uptake during exercise (peak VO(2)) (12.8+/-0.5 vs 15.6+/-0.5 ml/min/kg). While each of these parameters was a risk predictor in univariate analysis, multivariate analysis revealed that HRV provides both independent and additional prognostic information with respect to the risk 'cardiac mortality or deterioration of CHF'. It is concluded that the determination of HRV enhances the prognostic power given by the most widely used parameters LVEF and peak VO(2) in the prediction of mortality or deterioration of CHF and thus enables to improve risk stratification.

Do cytokines enable risk stratification to be improved in NYHA functional class III patients? Comparison with other potential predictors of prognosis.

AIMS: Elevated plasma levels of proinflammatory cytokines have been reported in patients with congestive heart failure. The purpose of this study was to assess whether cytokines improve risk stratification in a homogeneous group of NYHA class III patients with a left ventricular ejection fraction <40%. METHODS AND RESULTS: Plasma concentrations of big endothelin, tumour necrosis factor alpha, interleukins -1, -6, -10 and -12, sCD14 and GM-CSF were measured by ELISA in 91 NYHA III patients [mean (SD) age: 55 (10) years, 69% male, 34% coronary artery disease, 66% dilated cardiomyopathy] with a left ventricular ejection fraction and a peak oxygen uptake (peak VO2) of 19 (9)% and 12.1 (3.6) ml x min(-1) x kg(-1), respectively. During follow-up [22 (13) months], 31 patients (34%) died due to cardiovascular causes. In non-survivors, interleukin-6 was twice as high as in survivors [12.8 (16.9) pg x ml(-1)vs 5.6(5.3) pg x ml(-1), P<0.003], whereas plasma concentrations of the other cytokines showed no significant differences. Concerning long-term survival (> or =1 year), multivariate Cox regression analysis revealed an independent prognostic power for interleukin-6, which was further improved by combining with left ventricular ejection fraction and peak VO2, while for short-term survival (up to 6 months) interleukin-6 did not allow risk stratification. CONCLUSION: In NYHA class III patients, plasma concentrations of interleukin-6 are predictive of long-term survival. However, its value may be limited for clinical decision-making for cardiac transplantation (short-term survival).

Visual categorical perception by rats with temporal, striate, or sham ablations.

Rats were trained to discriminate a 0 degrees stripe from a 90 degrees stripe in a two choice water maze. They were prepared with either Te2/3, partial striate (PS), or sham lesions and retrained on the preoperative discrimination. In two separate experiments, excellent savings was observed for all groups. Next, trials were administered with novel stripe orientations defined as either between- or within-category problems. Performance accuracy eroded rapidly for all groups in the first experiment, and no between-group differences were observed. In the second experiment, each session with categorical stimuli was preceded by four reminder trials with the original stimuli. This improved accuracy for all groups, but it was found that animals with PS lesions, not animals with T2/3 lesions, were impaired on between-category judgements. The impairment was not secondary to a disruption of basic visual sensory processing or significantly larger lesions relative to the Te2/3 group. As is the case for monkeys, accuracy with within-category stimuli was inferior to between-category stimuli for all groups. Possible reasons for this inter-species difference are discussed.

Musculoskeletal fitness, health outcomes and quality of life.

The health benefits and quality-of-life outcomes of a fit musculoskeletal system (musculoskeletal fitness) are reviewed in this article. The World Health Organization suggests health is a state of complete physical, mental or social well-being and not merely the absence of disease or infirmity. Physical health includes such characteristics as body size and shape, sensory acuity, susceptibility to disease and disorders, body functioning, recuperative ability and the ability to perform certain tasks. One aspect of physical health is the musculoskeletal system, which consists of 3 components; muscular strength, endurance and flexibility. Muscular strength (dynamic) is defined as the maximum force a muscle or muscle group can generate at a specific velocity. Muscular endurance is the ability of a muscle or muscle group to perform repeated contractions against a load for an extended period of time. Flexibility has 2 components, dynamic or static, where dynamic flexibility is the opposition or resistance of a joint to motion, that is, the forces opposing movement rather than the range of movement itself. Static flexibility is the range of motion about ajoint, typically measured as the degree of arc at the end of joint movement. If strength, endurance and flexibility are not maintained, musculoskeletal fitness is then compromised which can significantly impact physical health and well-being. Many health benefits are associated with musculoskeletal fitness, such as reduced coronary risk factors, increased bone mineral density (reduced risk of osteoporosis), increased flexibility, improved glucose tolerance, and greater success in completion of activities of daily living (ADL). With aging, the performance of daily tasks can become a challenge. Additionally, falls, bone fractures and the need for institutional care indicate a musculoskeletal weakness as we age. The earlier in life an individual becomes physically active the greater the increase in positive health benefits; however, becoming physically active at any age will benefit overall health. Improved musculoskeletal fitness (for example, through resistance training combined with stretching) is associated with an enhanced health status. Thus, maintaining musculoskeletal fitness can increase overall quality of life.

Risk stratification in middle-aged patients with congestive heart failure: prospective comparison of the Heart Failure Survival Score (HFSS) and a simplified two-variable model.

AIMS: The performance of a US-American scoring system (Heart Failure Survival Score, HFSS) was prospectively evaluated in a sample of ambulatory patients with congestive heart failure (CHF). Additionally, it was investigated whether the HFSS might be simplified by assessment of the distance ambulated during a 6-min walk test (6'WT) instead of determination of peak oxygen uptake (peak VO(2)). METHODS AND RESULTS: In 208 middle-aged CHF patients (age 54+/-10 years, 82% male, NYHA class 2.3+/-0.7; follow-up 28+/-14 months) the seven variables of the HFSS: CHF aetiology; heart rate; mean arterial pressure; serum sodium concentration; intraventricular conduction time; left ventricular ejection fraction (LVEF); and peak VO(2), were determined. Additionally, a 6'WT was performed. The HFSS allowed discrimination between patients at low, medium and high risk, with mortality rates of 16, 39 and 50%, respectively. However, the prognostic power of the HFSS was not superior to a two-variable model consisting only of LVEF and peak VO(2). The areas under the receiver operating curves (AUC) for prediction of 1-year survival were even higher for the two-variable model (0.84 vs. 0.74, P<0.05). Replacing peak VO(2) with 6'WT resulted in a similar AUC (0.83). CONCLUSION: The HFSS continued to predict survival when applied to this patient sample. However, the HFSS was inferior to a two-variable model containing only LVEF and either peak VO(2) or 6'WT. As the 6'WT requires no sophisticated equipment, a simplified two-variable model containing only LVEF and 6'WT may be more widely applicable, and is therefore recommended.

Transforming an EPA QA/R-2 quality management plan into an ISO 9002 quality management system.

The Environmental Protection Agency's (EPA) Office of Emergency and Remedial Response (OERR) requires environmental data of known quality to support Superfund hazardous waste site projects. The Quality Assurance Technical Support (QATS) Program is operated by Shaw Environmental and Infrastructure, Inc. to provide EPA's Analytical Operations Center (AOC) with performance evaluation samples, reference materials, on-site laboratory auditing capabilities, data audits (including electronic media data audits), methods development, and other support services. The new QATS contract awarded in November 2000 required that the QATS Program become ISO 9000 certified. In a first for an EPA contractor, the QATS staff and management successfully transformed EPA's QA/R-2 type Quality Management Plan into a Quality Management System (QMS) that complies with the requirements of the internationally recognized ISO 9002 standard and achieved certification in the United States, Canada, and throughout Europe. The presentation describes how quality system elements of ISO 9002 were implemented on an already existing quality system. The psychological and organizational challenges of the culture change in QATS' day-to-day operations will be discussed for the benefit of other ISO 9000 aspirants.

Aberrant internal carotid artery in the middle-ear space.

The incidence of an aberrant internal carotid artery in the middle ear is approximately one per cent and most patients are asymptomatic. We present two patients with an aberrant internal carotid artery who presented with pulsatile tinnitus and an intra-tympanic mass. Here we discuss the clinical presentation, relevant radiographic investigations and further management of these patients.

PGAM-M expression is regulated pretranslationally in hindlimb muscles and under altered loading conditions.

Enzymatic activity from the muscle-specific isoform of phosphoglycerate mutase (PGAM-M) is higher within glycolytic skeletal muscles than in oxidative muscles. The hypothesis that PGAM-M is regulated pretranslationally among muscles of the hindlimb was tested using enzymatic assays, Western blots, and Northern blots. We further investigated the regulatory level(s) at which PGAM-M gene expression is controlled during hindlimb unweighting. PGAM-M mRNA and immunoreactive protein levels were fourfold lower in the rat soleus muscle than in the tibialis anterior (TA), plantaris, and extensor digitorum longus muscles. Four weeks of unweighting induced a 2.5-fold increase in PGAM enzymatic activity within the soleus muscle, a 1.8-fold increase in PGAM-M immunoreactivity, and a 3. 5-fold increase in PGAM-M mRNA. To examine potential transcriptional regulatory mechanisms, the proximal 400 bp of the rat PGAM-M promoter were linked to a firefly luciferase and injected into normal and unweighted TA and soleus muscles. Firefly luciferase activity was elevated two- to threefold in the TA and the unweighted soleus over the normal soleus muscle. These data suggest that PGAM-M expression is pretranslationally regulated among muscle types and within unweighted slow-twitch muscle. Furthermore, the proximal 400 bp of the PGAM-M promoter contains cis-acting sequences to allow muscle-type-specific expression of a reporter gene and responsiveness to soleus muscle unweighting.

Psychological adjustment of adolescents with sickle cell disease: relations with demographic, medical, and family competence variables.

OBJECTIVE: Investigate the hypothesis that family competence in addressing challenges associated with sickle cell disease (SCD) contributes to adolescents' adjustment. METHOD: During routine clinic appointments, 80 adolescents (M age = 14.4 years) and their parents independently completed the Self-Report Family Inventory (SFI), which assesses family competence, and measures of adolescent adjustment problems. Information related to disease severity was obtained from clinic files. RESULTS: Regression analyses controlling for demographic and medical variables revealed that higher family competence was associated with fewer internalizing and externalizing behaviors by the adolescent; these relations were particularly true for younger adolescents and for girls. Parental reports of somatic complaints in girls were predicted by parental ratings of family competence. DISCUSSION: Interventions for adolescents with SCD should be family-centered and should focus on strengthening the family's ability to manage stressors associated with parenting an adolescent with a chronic illness.

Case study: audio feedforward treatment of selective mutism.

Selective mutism is a relatively rare and difficult-to-treat disorder. Audio feedforward is a potential intervention that involves having the individual with selective mutism listen to audiotapes edited to depict him or her speaking in situations in which he or she is not currently speaking. The successful use of this intervention for three children with selective mutism is reported. The intervention was used in both school and community settings. This intervention has not always proved successful, sometimes because children refused to make the audiotapes.

Peritonsillar haematoma.

We present one patient who was admitted with a peritonsillar haematoma as a complication of acute tonsillitis and concomitant warfarin therapy for prosthetic aortic valves. While tonsillar haemorrhage as a result of acute tonsillitis has been well described, no cases of isolated haematoma formation have been documented, nor has it been recognized previously as a complication of long-term anticoagulant therapy. We discuss establishing the diagnosis, the likely aetiology and implications of this complication.

Carbohydrate sources for gestational diabetes mellitus screening. A comparison.

One hundred eight patients were prospectively randomized to receive 50 g of a glucose polymer, d-glucose or a candy bar during a one-hour gestational diabetes mellitus (GDM) screening. The polymer had a mean serum glucose similar to that of d-glucose, with significantly fewer side effects, allowing an increased rate of examination completion. The candy bar produced a significantly lower mean serum glucose but had the highest rating for flavor. The polymer was an inexpensive and well-tolerated alternative for GDM screening, while the use of a candy bar needs more study.

Screening for gestational diabetes mellitus with a reflectance photometer: accuracy and precision of the single-operator model.

OBJECTIVE: To investigate the accuracy and precision of a recent-generation reflectance photometer, Accu-Chek III, for gestational diabetes mellitus screening with a single operator. METHODS: Four hundred ten paired capillary and serum glucose samples collected prospectively were evaluated by a reflectance photometer and a glucose oxidase method (Beckman), respectively, during routine gestational diabetes mellitus screening with a single operator. RESULTS: The mean Accu-Chek III result was 12% greater than serum glucose oxidase (115.5 +/- 1.4 and 103.4 +/- 1.3 mg/dL, respectively). A serum glucose level of at least 135 mg/dL by glucose oxidase produced sensitivity and specificity of 0.81 and 0.68, respectively. At 155 mg/dL, the Accu-Chek III sensitivity was 0.81 and specificity 0.74, and the method produced fewer false-positive results (37 of 410 [9.0%] versus 41 of 410 [10%]) than a 135-mg/dL serum cutoff. Adjusting the Accu-Chek III threshold by two times the coefficient of variation resulted in the same number of false positives as the Beckman technique at 135 mg/dL. The receiver operating characteristic curve cutoff for the venous value of 135 mg/dL was an Accu-Chek III value of 141 mg/dL. Linear regression analysis predicted y = 20.6 + 0.919x, r = 0.838. The mean coefficient of variation was 3.9%. CONCLUSIONS: The Accu-Chek III produced accurate and precise gestational diabetes mellitus screening results with a single operator. Because capillary blood is a combination of arterial and venous blood, an Accu-Chek III cutoff of 155 mg/dL may be more appropriate for screening, considering the 10-15% higher capillary glucose level in the fed state. An Accu-Chek III cutoff of 155 mg/dL produced a higher specificity than venous serum at 135 mg/dL, with no decrease in sensitivity.

Hyperkalemia after irradiation of packed red blood cells: possible effects with intravascular fetal transfusion.

Plasma potassium, calcium, and albumin concentrations in irradiated blood, and in fetal blood before and after transfusion, were measured. Dangerously high plasma potassium levels were observed in some units of irradiated packed red blood cells (range, 13.9 to 66.5 mEq/L; mean, 44.7 mEq/L) and could be one possible explanation for the high incidence of fetal arrhythmia associated with fetal intravascular transfusion. There are many factors operative in the preparation of irradiated packed red blood cells that may predispose to high potassium levels: the age of the red blood cells, the number of procedures used to concentrate the blood, the duration of time elapsed from concentration, the duration of time elapsed from irradiation, and the hematocrit. Use of fresh blood, avoidance of multiple packing procedures, limiting the hematocrit in the donor unit to less than or equal to 80%, and minimizing the time between concentration, irradiation and transfusion may minimize the potassium levels, and therefore making an additional washing procedure unnecessary.

Mercury as a health hazard.

Pink disease has virtually disappeared since teething powders were withdrawn. We describe a case in a boy who was exposed to metallic mercury vapour. We discuss the potential health hazard of spilled elemental mercury in the house and the difficulties of removing it from the environment.