Atrial Late Potentials in Patients with Paroxysmal Atrial Fibrillation Detected Using a High Gain, Signal-Averaged Esophageal Lead

High gain, signal-averaged ECGs using conventional surface lead technique and a transesophageal lead technique were performed in 45 idiopathic paroxysmal atrial fibrillation patients and in 33 normal controls. Both techniques showed increased P wave duration in patients compared with the controls (P < 0.001), but higher P wave amplitudes were obtained using the transesophageal technique compared with surface leads (patients: 169.8 ± 81.7 μV vs 15.8 ± 7.3 μV; P < 0.0005; controls: 163.5 ± 22.1 μV vs 18.5 ± 5.2 μV; P < 0.0005). The signal-averaged transesophageal lead, but not the surface recordings, identified the presence of atrial late potentials evidenced by lower root wean square voltages in the terminal portion of the P wave: in last 10 seconds, 4.4 ±1.3 μV versus 8.5 ± 3.0 μV; P < 0.001; in last 20 seconds, 7.0 ± 2.3 μV versus 16.0 ± 7.9 μV; P < 0.001; in last 30 seconds, 12.5 ± 5.3 μV versus 23.8 ± 12.8 μV; P < 0.001, in patients with respect to controls. The criterion P wave duration ≥ 110 msec had 85% sensitivity. 100% specificity, and 100% positive predictive value in identifying the patients; the combined criteria P wave duration ≥ 110 msec and root mean square for the last 10 msec ≤ 6.5 showed 80% sensitivity, 100% specificity, and 100% predictive value. The signal-averaged transesophageal lead produces a higher amplitude signal, which reveals fractionation of atrial activation in atrial fibrillation and allows identification of individuals predisposed to this arrhythmia.     

Relation between physical fitness and gross motor capacity in children and adolescents with cerebral palsy

Aim  To examine the relation between physical fitness and gross motor capacity in children with cerebral palsy (CP) who were classified in Gross Motor Function Classification System levels I or II.
Method  In total, 68 children with CP (mean age 12y 1mo, SD 2y 8mo; 44 males, 24 females; 45 classified as having spastic unilateral CP, 23 as having spastic bilateral CP) participated in this study. All participants performed a maximal aerobic exercise test (10m Shuttle Run Test), a short-term muscle power test (Muscle Power Sprint Test), an agility test (10×5m sprint test), and a functional muscle strength test (30s repetition maximum) within 2 weeks. Gross motor capacity was concurrently assessed using dimensions D (standing) and E (walking, running, and jumping) of the 88-item version of the Gross Motor Function Measure (GMFM).
Results  No relation between aerobic capacity, body mass index, and dimensions D and E of the GMFM was found. The correlations between short-term muscle power, agility, functional muscle strength, and dimensions D and E of the GMFM were moderate to high ( r ∼0.6–0.7).
Interpretation  The relations found between short-term muscle power, agility, functional muscle strength, and gross motor capacity indicate the importance of these components of physical fitness, and may direct specific interventions to maximize gross motor capacity in children and adolescents with CP.     

A critique of elective pediatric supraglottic airway devices

In 1988, when the Laryngeal Mask Airway-Classic™ (Intavent Orthofix, Maidenhead, UK), was introduced there were only two choices of airway management: tracheal tube or facemask. The supraglottic airway, as we now understand the term, did not exist. Yet, 20 years later, we are faced with an ever increasing choice of supraglottic airway devices (SAD). For many SADs, with the exception of the LMA-Classic^TM and LMA-Proseal^TM (Intavent Orthofix, Maidenhead, UK), there is a lack of high quality data of efficacy. The best evidence requires a randomized controlled trial comparing a new device against an established alternative, properly powered to detect clinically relevant differences in clinically important outcomes. Such studies in children are very rare. Safety data is even harder to establish particularly for rare events such as aspiration. Therefore, most safety data comes from extended use rather than high quality evidence which inevitably biases against newer devices. For reason of these factors, claims of efficacy and particularly safety must be interpreted cautiously. This narrative review aims to present the evidence surrounding the use of currently available pediatric SADs in routine anesthetic practice.     

Highway driving performance and cognitive functioning the morning after bedtime and middle‐of‐the‐night use of gaboxadol,zopiclone and zolpidem

Gaboxadol is a selective extrasynaptic GABA_A receptor agonist previously in development for the treatment of insomnia. Due to its short half‐life (1.5–2 h) it is expected to be free from residual effects the next morning. The present study assessed the residual effects of evening and middle‐of‐the‐night administration of 15 mg of gaboxadol on cognitive, psychomotor and driving performance. Twenty‐eight healthy volunteers entered the study with 25 (12 women; mean age 31.4 years) completing a double‐blind, placebo‐controlled, active‐referenced five‐way cross‐over study. Each treatment night subjects ingested one capsule at 23:00 hours and one at 04:00 hours. Treatments were placebo at both times, 15 mg gaboxadol or 7.5 mg zopiclone followed by placebo, and placebo followed by 15 mg gaboxadol or 10 mg zolpidem. Effects on cognition and psychomotor performance were assessed between 07:30 and 08:30 hours and on driving between 09:00 and 10:00 hours. Driving, as measured by standard deviation of lateral position in an on‐the‐road driving test, was almost significantly (P < 0.07) impaired after evening administration of gaboxadol for the all‐subjects‐completed set (n = 25) but significantly (P < 0.05) in the full analysis set (n = 28). Effects of all other active treatments on driving were significant. Evening administration of gaboxadol had minor effects on divided attention only, whereas middle‐of‐the‐night administration impaired performance significantly in all tests except memory. Zolpidem and zopiclone impaired performance significantly in every test except tracking after zopiclone; 15 mg of gaboxadol can produce minor residual effects on driving after evening administration. Administration later at night is associated with moderately impairing residual effects on driving and psychomotor performance but not on memory.     

Pneumococcal antibody responses in elite swimmers

The ability of elite swimmers to mount an antibody response to the pneumococcal vaccine, Pneumovax 23, was assessed at the end of an intensive 12-week training programme. Antibody titres to six pneumococcal polysaccharide types were measured in 20 elite swimmers (10 male, 10 female) aged 17–23 years and 19 sedentary age- and sex-matched students (eight male, 11 female) aged 18–23 years. Blood samples were tested 14 days apart to assess the magnitude of the antibody response and changes in serum immunoglobulin isotypes and IgG subclasses. There were no significant differences in any of the pneumococcal antibody responses to the Pneumovax between swimmers and controls, and no gender effect, either before or after vaccination. The clinically adequate response to the vaccine was greatest for the pneumococcal serotype 4, which was 97% for the total study population. There were no significant correlations between the magnitude of any of the pneumococcal antibody responses and (i) changes in the scores for the swimmers’ international performance; (ii) infection rates in either swimmers or controls; (iii) any psychological variables, assessed by the Profile of Mood States (POMS) questionnaire for either swimmers or controls. Swimmers had significantly lower concentrations of serum IgG2 (P = 0·04) and IgG3 (P = 0·002) before pneumococcal vaccination. The swimmers had an increase in all immunoglobulin isotypes and IgG subclasses post-vaccination, suggesting a polyclonal response to the vaccine that was not observed in control subjects. The magnitude of the subclass responses after vaccination was significantly greater in swimmers compared with controls for IgG1 (P = 0·04), IgG3 (P = 0·04) and IgG4 (P = 0·01). The data indicated that elite swimmers undertaking an intensive training programme were capable of mounting an antibody response to pneumococcal antigens equivalent to that of age- and sex-matched sedentary control subjects, despite the swimmers having lower prevaccination levels of serum immunoglobulins.     

Design of active analogues of a 15-residue peptide using D-optimal design,QSAR and a combinatorial search algorithm

This report describes the rational design of novel analogues of a 15-residue antibacterial peptide CAMELO. A constrained D-optimal design was carried out to derive a training set of 60 analogues. Partial least squares (PLS) models describing quantitative structure-activity relationships (QSARs) were initially derived for the peptides using two published and one novel parameter set. The novel ‘Design parameters’ were based on key structural features identified in hypothetical models of the mechanisms by which peptides interact with cell membranes. In an extension of the PLS method, influence statistics were used to decrease the weighting of compounds having a large effect on model predictions. A combinatorial search algorithm was developed which used PLS models as predictors to select a test set of 39 peptides with high predicted potencies. Within this set, the most potent analogue CAMEL135, which contained seven point mutations from CAMEL0, was identified. For a panel of 24 bacteria, the mean MIC value of CAMEL135 was approximately half of that for CAMEL0. For the parameter sets tested, covariance functions derived from Z-scales gave highest Q²-values for the training set, whilst the model using the the ‘Design parameters’ gave least error when predicting the activity of the test set. The predictive ability of a third published set of peptide parameters was found to compare favourably with that of the parameters used in the design. Analysis of the PLS models indicates that hydrophobicity and amphipathicity are the most important features influencing activity for this class of compound. © Munksgaard 1997.     

ELEVATED CARBOHYDRATE-DEFICIENT TRANSFERRIN PREDICTS PROLONGED INTENSIVE CARE UNIT STAY IN TRAUMATIZED MEN

Carbohydrate-deficient transferrin (CDT) is reported to havea higher specificity in alcoholism than conventional markers.As the morbidity and mortality rates amongst chronic alcoholicsare raised following trauma, the objective was to investigateif CDT could be used to predict prolonged intensive care Unit(ICU) stay and an increased morbidity in patients with multipleinjuries admitted to the ICU. In this prospective double-blindstudy, 66 traumatized male patients were transferred to theICU following admission via the emergency room and operativemanagement. Blood samples for CDT determination were taken uponadmission to the emergency room, the ECU and on days 2 and 4following admission. The patients were allocated a priori totwo groups; high CDT group (CDT > 20 U/I on admission tothe emergency room) and low CDT group (CDT     

Sexual behaviour of drug injectors in London: implications for HIV transmission and HIV prevention

The importance of sharing infecting equipment in the transmission dynamics of HIV is well established. Comparatively less is known about the sexual behaviour of drug injectors and the risks posed to themselves and their sexual partners through the sexual transmission of HIV. Findings are reported from survey-based interviews undertaken in 1991 which investigated the sexual behaviour of 516 drug injectors, both in and out of treatment in London. The majority of respondents (80%) were sexually active in the 6 months preceding interview. During this time, respondents had a mean of 2.1 non-commercial opposite sex partners. Most (66%) had vaginal intercourse at least once a week, although 68% never used condoms with primary partners and 34% never used condoms with casual partners. Those having sexual intercourse most often were less likely to use condoms. Many had non-injecting sexual partners, and 62% of respondents' primary and casual partners did not inject drugs. Confirmed saliva HIV test results show 10% of respondents to be antibody positive, with a higher rate of prevalence (14% positive) among those with no experience of treatment. This group were also more likely la report casual sexual intercourse. The average rate of partner change, the high proportion of drug injectors with non-injecting partners and the infrequency of condom use within primary and casual relationships indicates the potential for HIV transmission between injectors and their non-injecting sexual partners. The paper concludes by emphasizing the importance of outreach and community-based intervention in safer sex health promotion.     

Radiofrequency Catheter Ablation of a Macroreentrant Ventricular Tachycardia Late After Surgical Repair of Tetralogy of Fallot Using the Electroanatomic Mapping (CARTO)

This case report describes a patient with a sustained monomorphic VT after surgical repair of a tetralogy of Fallot (TOF). In combination with the three-dimensional electroanatomic mapping system, CARTO, and conventional mapping techniques the VT was identified as a macro-reentrant tachycardia circling around the border between pulmonary graft and right ventricular outflow tract (RVOT). A y-shaped ablation line crossing this zone was created. The VT terminated during RF application and was not inducible again. This case underlines the use of a combined conventional and three-dimensional electroanatomic mapping technique can be helpful for catheter ablation of ventricular arrhythmias in TOF patients. (PACE 2004; 27[Pt. I]:801–804)