Cardiac pacing for severe childhood neurally mediated syncope with reflex anoxic seizures

OBJECTIVE

To determine whether permanent cardiac pacing could prevent syncope and seizures in children with frequent severe neurally mediated syncope, and if so whether dual chamber pacing was superior to single chamber ventricular pacing.

METHODS

Dual chamber pacemakers were implanted into 12 children (eight male, four female) aged 2-14 years (median 2.8 years) with frequent episodes of reflex anoxic seizures and a recorded prolonged asystole during an attack. The pacemaker was programmed to sensing only (ODO), single chamber ventricular pacing with hysteresis (VVI), and dual chamber pacing with rate drop response (DDD) for four month periods, with each patient allocated to one of the six possible sequences of these modes, according to chronological order of pacemaker implantation. The parent and patient were blinded to the pacemaker mode and asked to record all episodes of syncope or presyncope ("near miss" events). The doctor analysing the results was blinded to the patient and pacemaker mode.

RESULTS

One patient was withdrawn from the study after the pacemaker was removed because of infection. In the remaining children, both dual chamber and single chamber pacing significantly reduced the number of syncopal episodes compared with sensing only (p = 0.0078 for both). VVI was as effective as DDD for preventing syncope, but DDD was superior to VVI in reducing near miss events (p = 0.016).

CONCLUSIONS

Permanent pacing is an effective treatment for children with severe neurally mediated syncope and reflex anoxic seizures. VVI is as effective as DDD in preventing syncope and seizures, but DDD is superior in preventing overall symptoms.

Transhepatic approach for cardiac catheterisation in children: initial experience

AIM

To assess initial experience of cardiac catheterisation in children by the transhepatic approach where conventional venous access is impossible.

PATIENTS AND METHODS

Percutaneous transhepatic cardiac catheterisation was performed on six occasions in five children (three male) aged 4 to 36 months (mean 17 months). All children had documented femoral venous occlusion and all but one had occlusion of the superior vena cava. Ultrasound was used in five of the six procedures to help identify a large hepatic vein. A 4 F or 5 F sheath was introduced into the vein using the Seldinger technique. In the fourth patient, hepatic venous access was obtained immediately without the assistance of ultrasound.

RESULTS

Percutaneous transhepatic catheterisation was successfully performed at all six attempts. Total procedure time ranged from 120 to 200 minutes (mean 138 minutes) and screening time from 14 to 22 minutes (mean 16.8 minutes). A serious complication was encountered in only one patient who had a retroperitoneal bleed after administration of thrombolysis for loss of femoral arterial pulse.

CONCLUSIONS

The percutaneous transhepatic technique can provide a safe alternative approach for cardiac catheterisation in children with multiple venous occlusion. The procedure can be performed very simply using the Seldinger technique and equipment normally used for conventional venous cannulation for cardiac catheterisation.

Food ads on TV: a health hazard for children?

OBJECTIVE

To examine the nutritional quality of food in television food advertisements that are targeted at children.

METHOD

We videotaped 42 hours of children's programs and analysed the food advertisements' content and nutrient composition using the New Zealand Food Composition Database.

RESULTS

Of 269 food advertisements, 63% were for foods 'high in fat and/or sugar'. Children who ate only the advertised foods would eat a diet too high in fat, saturated fat, protein, free sugars and sodium. Furthermore, their diets would have suboptimal levels of fibre and suboptimal intakes of a number of important micronutrients (depending on age), including magnesium, selenium and vitamin E. The food products advertised on this channel rarely included nutritious low-cost foods that are necessary for food security in low-income groups. There were also no food advertisements that included any of the healthy foods consumed by Maori and Pacific peoples.

CONCLUSIONS

Food advertisements targeted at children generally reflect the dietary pattern associated with an increased risk of obesity and dental caries in childhood; and cardiovascular disease, diabetes and cancers in adulthood.

Identification of two novel mutations in keratin 13 as the cause of white sponge naevus

BACKGROUND

White sponge naevus (WSN) is a rare autosomal dominant condition which is characterised by benign, white spongy plaques (oral leukokeratoses) affecting non-cornifying, wet mucosa. WSN shares several ultrastructural characteristics (eg, epithelial thickening, acanthosis, keratin filament aggregation) with a number of epithelial disorders caused by mutations in keratin genes and to-date two mutations, one in each of the mucosal specific keratins, K4 and K13, have been identified as the molecular basis of the disorder.

OBJECTIVES

To identify the molecular basis of WSN in two families with a history of the disease.

RESULTS

Two novel mutations were identified in helix initiation motif of K13. A T-to-C transition was found in the affected members of one family which is predicted to change leucine115 to proline. In the second family, a similar T-to-C transition was found in codon 108 which is predicted to change methionine to threonine in the protein sequence. These changes were not found in 50 unrelated, unaffected individuals.

CONCLUSIONS

The mutations in the helix initiation motif of K13 are the cause of WSN in these families. These cases confirm mutations in the mucosal specific keratins as a significant cause of the disorder.

High throughput detection of retrovirus-associated reverse transcriptase using an improved fluorescent product enhanced reverse transcriptase assay and its comparison to conventional detection methods

The development and application of a novel, sensitive TaqMan fluorescent probe-based product enhanced RT test (F-PERT) for the detection of retrovirus are described. The assay allows discrimination between the amplification signals generated by genuine positive signals that result from retroviral RT activity and the RT-like activity from DNA polymerases. The RT-like activity from DNA polymerases was suppressed by the addition of activated calf-thymus DNA with no reduction in the RT activity. A linear relationship between threshold cycle (C(T)) and the number of virus particles was demonstrated, allowing quantification of retroviruses in unknown samples. The F-PERT assay was able to detect a wide range of retroviral RT activities, including that from porcine endogenous retrovirus (PoERV), murine leukaemia virus (MLV), simian foamy virus (SFV), simian immunodeficiency virus (SIVmac) and squirrel monkey retrovirus (SMRV). The detection limit of SMRV, MLV and PoERV was approximately 100 virion particles and the test was able to detect at least 10(2) molecules of purified RT enzyme. RT activity was not detected in cellular lysates and supernatants from MRC-5, BT, VERO, or Raji cells, whereas RT activity was detected in C1271, Mus dunni, K-Balb, BHK-21, CHO-K1, SP2/0-Ag14 and NSO cell supernatants. RT activity was also detected in the Spodoptera cell line Sf9.

Content analysis and publication outcomes of projects by public health medicine registrars

OBJECTIVE

To examine the content of the project work of public health medicine registrars in New Zealand and identify publication outcomes.

METHOD

All projects submitted during 1987-97 were examined and key aspects captured on a database. Literature searches using Medline, Health Star, Index New Zealand and the NZ National Library catalogue were undertaken.

RESULTS

A total of 355 registrar projects produced by 91 registrars were identified. Only 29% of these projects were associated with one or more publications that could be identified in electronic databases commonly available to New Zealanders and only 16% of them were associated with an article in the Medline-indexed literature. A possible cause for concern is the relatively small amount of project work (6% of projects) that was directly on Maori and/or Pacific Peoples' health. There also appears to be a relative lack of project work on chronic disease epidemiology and control, tobacco control and the socio-economic determinants of health.

CONCLUSIONS

Given the relatively high quality of registrar project work, a publication rate of only 29% is probably suboptimal. The subject matter of registrar projects appears to infrequently address certain major areas of public health importance including Maori and Pacific Peoples' health.

IMPLICATIONS

Consideration should be given to addressing these issues by those involved in public health medicine training.

Transcatheter closure of a large coronary artery fistula with the Amplatzer duct occluder

We report the successful percutaneous closure of a large coronary artery fistula from the obtuse marginal artery to the right ventricle in an 8-month-old boy using the Amplatzer duct occluder. The device was positioned and deployed via the venous system, using a guidewire that had been advanced via the aorta, coronary artery, and fistula to the venous circulation. Cathet. Cardiovasc. Intervent. 48:188-190, 1999.

Transcatheter closure of atrial septal defect and interatrial communications with a new self expanding nitinol double disc device (Amplatzer septal occluder): multicentre UK experience

OBJECTIVE

To review the safety and efficacy of the Amplatzer septal occluder for transcatheter closure of interatrial communications (atrial septal defects (ASD), fenestrated Fontan (FF), patent foramen ovale (PFO)).

DESIGN

Prospective study following a common protocol for patient selection and technique of deployment in all participating centres.

SETTING

Multicentre study representing total United Kingdom experience.

PATIENTS

First 100 consecutive patients in whom an Amplatzer septal occluder was used to close a clinically significant ASD or interatrial communication.

INTERVENTIONS

All procedures performed under general anaesthesia with transoesophageal echocardiographic guidance. Interatrial communications were assessed by transoesophageal echocardiography with reference to size, position in the interatrial septum, proximity to surrounding structures, and adequacy of septal rim. Stretched diameter of the interatrial communications was determined by balloon sizing. Device selection was based on and matched to the stretched diameter of the communication.

MAIN OUTCOME MEASURES

Success defined as deployment of device in a stable position to occlude the interatrial communication without inducing functional abnormality or anatomical obstruction. Occlusion status determined by transoesophageal echocardiography during procedure and by transthoracic echocardiography on follow up. Clinical status and occlusion rates assessed at 24 hours, one month, and three months.

RESULTS

101 procedures were performed in 100 patients (86 ASD, 7 FF, 7 PFO), age 1.7 to 64.3 years (mean (SD), 13.3 (13.9)), weight 9.2 to 100.0 kg (mean 32.5 (23.5)). Procedure time ranged from 30 to 180 minutes (mean 92.4 (29.0)) and fluoroscopy time from 6.0 to 49.0 minutes (mean 16.1 (8.0)). There were seven failures, all occurring in patients with ASD, and one embolisation requiring surgical removal. Immediate total occlusion rate was 20.4%, rising to 84.9% after 24 hours. Total occlusion rates at the one and three month follow up were 92.5% and 98.9%, respectively. Complications were: transient ST elevation (1), transient atrioventricular block (1), presumed deep vein thrombosis (1), presumed transient ischaemic attack (1).

CONCLUSIONS

It appears feasible to close interatrial communications and atrial septal defects up to 26 mm stretched diameter safely with the Amplatzer septal occluder. Short term results confirm an early high occlusion rate with no major complications. Careful selection of cases based on the echocardiographic morphology of the ASD and accurate assessment of their stretched diameter is of utmost importance. Further experience with the larger devices and longer term results are required before a firm conclusion regarding its use can be made.

Assessment of the quality of neonatal echocardiographic images transmitted by ISDN telephone lines

OBJECTIVE

To assess the quality of echocardiographic images from neonates transmitted over Integrated Service Digital Network 2 (ISDN2) channels.

DESIGN

Echocardiographic images were viewed live in real time either by a direct video link or by transmission over the commercial network, using one, two, or three ISDN2 channels. The order of the viewing formats was random and four observers marked each view for potential for provision of complete diagnostic information and quality.

SETTING

Cardiology department of tertiary referral centre for paediatric cardiac services. ISDN lines were positioned in two nearby rooms. Telephone connection was through the commercial network and video connection by a direct video cable.

PATIENTS

10 neonates were studied (weight 2600 to 3900 g). In each, nine echocardiographic studies were undertaken to assess imaging (M mode and cross sectional) and Doppler (spectral and colour) quality.

RESULTS

No significant differences were found in diagnostic ability between the different formats for M mode, colour, or spectral Doppler studies. For cross sectional imaging the diagnostic information and image quality increased with increasing numbers of ISDN channels. With six channels there was little difference from the directly connected images.

CONCLUSIONS

In echocardiographic assessment of the newborn, one or two ISDN2 channels will transmit images of satisfactory quality in many situations but three or more channels are necessary to ensure minimum degradation of the live image.

Diabetes in New Zealand--better information needed

AIMS

To review the availability and quality of data on the epidemiology of diabetes in New Zealand.

METHODS

A search was undertaken for all Medline-indexed publications on diabetes in New Zealand. Hospitalisation and mortality data (ICD9 code 250) from the New Zealand Health Information Service (NZHIS) were examined.

RESULTS

Information on diabetes in New Zealand has come from community surveys, national surveys, diabetes registers, hospitalisation data and mortality data. Much of this information has been valuable, but there is still inadequate national information on diabetes prevalence, incidence and time trends.

CONCLUSION

Information technology provides an opportunity to couple the surveillance of diabetes with improved diabetes care. Medical practitioners need to support the development of their own practice-based registers/recall systems and to contribute to the development of district-based diabetes registers where these have a central focus on improving diabetes care.

Reduced heart rate variability following repair of tetralogy of Fallot

OBJECTIVE

To examine autonomic function as assessed by heart rate variability in patients 10 or more years after repair of tetralogy of Fallot, and to relate this to cardiac structure, function, and electrocardiographic indices.

METHODS

Heart rate variability was measured by standard time domain techniques on a 24 hour Holter ECG in 28 patients, aged 12 to 34 years (mean 19.5), who had undergone repair of tetralogy of Fallot at least 10 years previously. Echocardiography was performed to assess left ventricular size and function, right ventricular size and pressure, and any proximal pulmonary arterial stenosis. Right ventricular function was evaluated by radionuclide scan. QRS duration, QT interval, and QT dispersion were measured on a standard 12 lead ECG. Measurements of heart rate variability were compared with values from 28 age matched healthy controls (mean age 19.9 years). Interrelations between variables were assessed using Pearson correlation coefficients and stepwise regression analysis.

RESULTS

Heart rate variability was reduced, compared with values for age matched normal controls, in 12 of the 28 patients. Reduced heart rate variability was associated with increased age, increased right ventricular size and pressure, and widening of the QRS complex.

CONCLUSIONS

Reduced heart rate variability is a feature following repair of tetralogy of Fallot. It is associated with increasing age, impaired right ventricular haemodynamics, and widening of the QRS complex. Under these circumstances, reduced heart rate variability may be a marker for deteriorating right ventricular function. Increased QRS duration has been identified as a risk factor for sudden death following repair of tetralogy of Fallot, and impaired cardiac autonomic control may be one of the mechanisms involved.

Tobacco control in New Zealand from 1945 to 1961

The 1945 to 1961 period was characterised by a significant increase in the international scientific knowledge of the health risks of smoking. Despite this, there was relatively little response by the New Zealand Government, the New Zealand medical profession and other local agencies. Specific tobacco control activities were virtually limited to some episodic and low profile publicity measures, and an incidental increase in tobacco taxation. This limited response may have partly been due to the slow diffusion of the health risk information to health professionals in this country and the presence of other more obvious health concerns (such as polio epidemics). Other reasons may have been the absence of a New Zealand research base, the lack of focused advocacy groups, political wariness about using tobacco taxation, a minimalist approach by government to product safety regulation and the major extent to which smoking was normalised within New Zealand society. Britain and the US led to further research. Reports linking lung cancer to smoking were published in 1950 by Doll and Hill in Britain, and by Wynder and Graham in the US. As a result of subsequent prospective studies, the American Cancer Society and the British Medical Research Council produced in 1954, independent reports that death rates were higher for cigarette smokers. A number of further studies on smoking and health were published in Britain and the US during the 1950s (e.g. by Doll and Hill in 1954), and the Medical Research Council and the United States Surgeon General gave further strong warnings. However, the unease of some parts of the medical world with the new science of epidemiology was reflected in the confusion by public and politicians over the conclusiveness of the evidence. Nevertheless, by the late 1950s there was evidence of declining tobacco consumption amongst US doctors, partly at least because of concern about health risks such as lung cancer.

Outcomes of transposition of the great arteries in the ear of atrial inflow correction

OBJECTIVE

To examine long term morbidity and mortality following atrial inflow corrective procedures for transposition of the great arteries (TGA) and to investigate factors that influence morbidity and mortality.

DESIGN

Retrospective cohort study from a single centre.

SETTING

Cardiology and cardiothoracic surgical unit in a large tertiary referral centre.

PATIENTS

All 130 patients who had TGA diagnosed between August 1972 and May 1988 and were considered suitable for atrial inflow correction; 109 of these underwent surgery (operative cohort: 84 Mustard operations and 25 Senning operations); 95 survived to hospital discharge (hospital surviving cohort).

MAIN OUTCOME MEASURES

Death and cardiac events.

RESULTS

There were relatively good long term results from atrial inflow correction for TGA with 5, 10, and 15 year survivals of 77.3%, 75.9%, and 71.3%. However, there was an appreciable incidence of late cardiac death and events, with 5, 10, and 15 year cardiac event-free survivals of 74.5%, 67.1%, and 39.6%. Supraventricular tachycardia was the only significant risk factor for late cardiac death (relative risk 8.72, 95% confidence interval, 2.86 to 26.64). Senning patients had better event-free survival (p = 0.04).

CONCLUSIONS

Atrial inflow correction for TGA has a reasonably good 15 year survival (71.3%), but there is an appreciable incidence of late cardiac deaths and events (15 year event-free survival 39.6%). The Senning procedure is preferable to the Mustard procedure for cases unsuitable for arterial switching.

Polygenis martinezbaezi (Siphonaptera: Rhopalopsyllidae) reared from a rodent nest found in the Peloncillo Mountains of southwestern New Mexico

A 3rd species of the flea genus Polygenis Jordan was added to the U.S. fauna by extension of known range from Mexico into New Mexico. Eleven males and 24 females of P. martinezbaezi Vargas were reared from a rodent nest, probably that of a yellow-nosed cotton rat, Sigmodon ochrognathus Bailey.

Sudden death 10 years after patch aortoplasty for coarctation

A 25-year-old man died 10 years after a Dacron patch was used to repair a coarctation of the aorta. Death was due to rupture of an unrecognized aneurysm at the site of the patch. After the initial operation at the age of 15 years, there had been no signs of residual or recurrent obstruction. He had no evidence of hypertension and was discharged some years later from regular hospital follow-up to the care of his general practitioner. We strongly recommend that patients who have undergone repair of aortic coarctation by patch aortoplasty should have lifelong follow-up in cardiac units with imaging facilities for monitoring aortic dilation. We would now recommend surgical intervention in the presence of progressive aortic dilation.

Short- and long-term efficacy. Childhood asthma

In clinical studies of asthma, great attention should be focused on the choice and validation of outcome measures. The outcome parameters to be used when evaluating efficacy of early intervention in childhood asthma treatment must be closely linked to the aims of the intervention and considered in the design of the study. In an interventional study, possible adverse consequences should also be considered as outcome measures when designing the study. The appropriate time span for assessing different types of interventions may vary from days to several decades, depending on the character of the intervention. Not only outcome parameters, such as improvement in symptom score and improvement of lung function, but also those that measure reduction in frequency and severity of acute exacerbations, reduction in morbidity and improvement in quality of life should be used. For some purposes, a more detailed approach to symptom severity is needed, such as separation of acute from chronic symptoms. Other outcome measures that need to be considered are: cost-effectiveness, normalization of inflammatory changes in the airways, control of airway hyperresponsiveness, airway growth and prevention of airway remodelling and importantly, whether an intervention against asthma can alter the natural course, or cure, the disease. Interventions should be evaluated to see to what extent such aims have been met.

Rotational ablation assisted angioplasty of an obstructed aortopulmonary collateral artery

A 15 month old baby girl with pulmonary atresia, ventricular septal defect, and multiple aortopulmonary collateral arteries underwent rotational ablation assisted balloon angioplasty of a severely stenosed collateral artery that had previously proved undilatable using a high pressure non-compliant balloon angioplasty catheter. It is postulated that the rotablation debulked a fibrotic stricture within the artery to facilitate effective balloon dilatation. Rotational ablation assisted angioplasty may have a role to play in congenital stenotic lesions that are "undilatable".

Aspergillus flavus endocarditis in a child with neuroblastoma

We report a case of Aspergillus flavus endocarditis in a 6-year-old boy with stage IV neuroblastoma with no pre-existing cardiac disease. The infection was successfully treated with high-dose liposomal amphotericin (AmBisome) once daily. Recurrence was prevented with itraconazole oral solution once daily as maintenance therapy. Adjunctive surgery was not required. The patient's cardiac function was uncompromised, but subsequent death from progressive neuroblastoma prevented long-term follow-up.

Novel preconcentration technique for on-line coupling to high-speed narrow-bore capillary gas chromatography: sample enrichment by equilibrium (ab)sorption. II. Coupling to a portable micro gas chromatograph

The technique of equilibrium (ab)sorption has been proven to be a powerful method for preconcentration of gaseous samples for high-speed narrow-bore capillary gas chromatography (GC) in general and field-portable GC instruments, often referred as micro GCs, in particular. Using a simple experimental set-up equipped with an open-tubular enrichment column it is possible to produce a homogeneously enriched sample plug, allowing reproducible injections of an enriched sample into the micro GC. Using a non-polar trapping column enrichment factors found for n-alkanes in the range of C7 to C10 ranged from 15 to 150 and agree well with calculated values. Using a highly retentive Thermocap column, the enrichment factor observed for heptane was above 500. As the use of this new preconcentration method requires only minimum modification of the micro GC, the chromatographic performance of the instrument was not compromised by direct coupling to the preconcentration device. Examples of on-line enrichment with portable micro GC analysis of VOCs from air are shown. These examples clearly demonstrate the potentials of the new method in field analysis.