Electroanatomical Mapping of the Heart: Basic Concepts and Implications for the Treatment of Cardiac Arrhythmias

The CARTO electroanatomical mapping system represents a paradigm shift in the ability to map the three-dimensional anatomy of the heart and determine the cardiac electrical activity at any given mapped point. The system associates anatomical structure and electrophysiological data and displays the combined information in an easily readable, visual fashion. The system consists of a roving mapping catheter with small magnetic sensors in the tip, a fixed sensor that acts as a reference point, a low magnetic field generating pad, and a data acquisition and display system. When the roving catheter is moved in three-dimensional space, its location in relation to the fixed sensor is monitored by the system, with a resolution of < 1 mm. By gating the acquisition of points in space to the cardiac electrical activity, points that represent both location and electrical activity at that location can be acquired and displayed on a computer screen. After acquiring a number of points, a three-dimensional representation is constructed, and may be displayed from any viewing projection. Clinical applications of the system include defining the mechanisms of arrhythmias, designing ablation strategies, guiding ablations, and improving the safety of mapping and ablation procedures by allowing localization of critical cardiac structures such as the atrioventricular node and His bundle. The system holds the potential to both further our understanding of arrhythmias and increase the safety, efficacy, and efficiency of catheter ablation.     

Polycystic Kidney Disease Re-evaluated: A Population-based Study

A genetic register of all known cases of autosomal dominantpolycystic kidney disease occurring in South and Mid-Wales hasbeen established. In a population of 2.1 million, 209 familieswith affected members were identified, 303 of whom are currentlyalive, 70 on renal replacement therapy. An additional 551 caseswould be predicted amongst family members at 50 per cent and25 per cent risk, giving an apparent prevalence of 1:2459 inthe general population. Five possible new mutations were seenwhere adults with phenotypic autosomal dominant polycystic kidneydisease had both parents alive, age > 55 years with no cystsvisible on ultrasound. The take-on rate for renal replacementtherapy increased during 1970–79 but has apparently reacheda plateau of 4.8 cases per million population per year overthe last 8 years, despite a rapidly increasing acceptance ofuraemic patients as a whole (72/10⁶/year in 1988–89).Considerably more patients with autosomal dominant polycystickidney disease aged over 50 years were started on treatmentin 1980–89 than in 1970–79, but the survival overallimproved with time. All cases of autosomal dominant polycystickidney disease reaching end-stage renal disease are now beingtreated, but the apparent clinical prevalence of this conditionin our region is less than half the supposed gene frequency,suggesting that undiagnosed cases have a benign prognosis.     

Prenatal identification of potential donors for umbilical cord blood transplantation for Fanconi anemia

Reported here are studies of Fanconi anemia fetal cells that led to the first use of umbilical cord blood for hematopoietic reconstitution in a clinical trial. Prenatal diagnosis and HLA typing were performed in fetuses at risk for Fanconi anemia (FA) to identify, prior to birth, those that were unaffected with the syndrome and were HLA-identical to affected siblings. Umbilical cord blood was harvested at the delivery of these infants; assays of progenitor cells indicated the presence of colony-forming units-granulocyte-macrophage (CFU-GM) in numbers similar to those of bone marrow CFU-GM that are associated with successful engraftment in HLA-matched allogeneic bone marrow transplantation. The possibility that umbilical cord blood from a single individual can be used as an alternative to bone marrow for hematopoietic reconstitution has now been demonstrated by the successful engraftment of two patients with FA. Progenitor cell assays of umbilical cord blood collected at the birth of a child affected with FA, who had been misdiagnosed on the basis of chorionic villus sampling (CVS) studies, indicated a profound deficiency in colony formation, consistent with previously reported abnormalities in the growth of FA cells in vitro. These results suggest that the hematopoietic disorder in FA is related to an underlying problem with cell proliferation.     

Aspirin in Alzheimer's disease (AD2000): a randomised open-label trial

BACKGROUND: Cardiovascular risk factors and a history of vascular disease can increase the risk of Alzheimer's disease (AD). AD is less common in aspirin users than non-users, and there are plausible biological mechanisms whereby aspirin might slow the progression of either vascular or Alzheimer-type pathology. We assessed the benefits of aspirin in patients with AD. METHODS: 310 community-resident patients who had AD and who had no potential indication or definite contraindication for aspirin were randomly assigned to receive open-label aspirin (n=156; one 75-mg enteric-coated tablet per day, to continue indefinitely) or to avoid aspirin (n=154). Primary outcome measures were cognition (assessed with the mini-mental state examination [MMSE]) and functional ability (assessed with the Bristol activities of daily living scale [BADLS]). Secondary outcomes were time to formal domiciliary or institutional care, progress of disability, behavioural symptoms, caregiver wellbeing, and care time. Patients were assessed at 12-week intervals in the first year and once each year thereafter. Analysis of the primary outcome measures was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN96337233. FINDINGS: Patients had a median age of 75 years; 156 patients had mild AD, 154 had moderate AD, and 18 had concomitant vascular dementia. Over the 3 years after randomisation, in patients who took aspirin, mean MMSE score was 0.10 points higher (95% CI -0.37 to 0.57; p=0.7) and mean BADLS score was 0.62 points lower (-1.37 to 0.13; p=0.11) than in patients assigned to aspirin avoidance. There were no obvious differences between the groups in any other outcome measurements. 13 (8%) patients on aspirin and two (1%) patients in the control group had bleeds that led to admission to hospital (relative risk=4.4, 95% CI 1.5-12.8; p=0.007); three (2%) patients in the aspirin group had fatal cerebral bleeds. INTERPRETATION: Although aspirin is commonly used in dementia, in patients with typical AD 2 years of treatment with low-dose aspirin has no worthwhile benefit and increases the risk of serious bleeds.     

On the development of the European S3 guidelines on the systemic treatment of psoriasis vulgaris: structure and challenges

Background The development of evidence based guidelines is a demanding and time consuming process. Therefore it is important to share the knowledge and discuss the structure of these guidelines in detail. Objectives To present a method report on the development process of the European evidence based guidelines on the systemic treatment of psoriasis vulgaris with the aim to offer guidance to other guidelines groups with lesser experience and to critically appraise the methodology of the guidelines development process. Methods The guidelines are based on the previously evaluated literature from three European national evidence based guidelines and an additional systematic search and evaluation of new literature. Further steps included a structured consensus conference and a DELPHI procedure to develop the recommendations, as well as several internal and external reviews. All steps were coordinated by the Division of evidence based medicine in cooperation with a group of methodologists. Results A total of 114 studies were included, serving as base for the efficacy chapters of the intervention. The recommendations, based on the efficacy and the level of evidence of the included studies were discussed and finally consented by the guidelines group. After subsequent reviews the guidelines were presented to the European Dermatology Forum, European Academy of Dermatology and Venereology and Union Européenne des Médicins Spécialistes for approval and published in October 2009. Conclusion The development of European evidence based guidelines requires a coordinated structure which can be achieved by the integration of an experienced group of methodologists. Nevertheless further improvements are imaginable and might be considered for an update or other European evidence based guidelines.     

Does deficient sensorimotor experience affect drawing of human figures?

Development of visuomotor competence might result in an internalized body concept in relation to the outside world. Figure drawing has been used in an attempt to access this concept in normal children and in children with spina bifida causing lower limb sensorimotor abnormalities. Compared with normal children, the figure drawings of spina bifida children showed no significant distortion of the proportion of the lower limbs in relation to the head and body. This is in agreement with other methods attempting to access the body schema in these children.     

Homozygous and compound heterozygous mutations in the ATP6V1B1 gene in patients with renal tubular acidosis and sensorineural hearing loss

Mohebbi N, Vargas‐Poussou R, Hegemann SCA, Schuknecht B, Kistler AD, Wüthrich RP, Wagner CA. Homozygous and compound heterozygous mutations in the ATP6V1B1 gene in patients with renal tubular acidosis and sensorineural hearing loss. Distal renal tubular acidosis (dRTA) is characterized by the inability to excrete acid in the renal collecting ducts resulting in inappropriately alkaline urine and hyperchloremic (normal anion gap) metabolic acidosis in the context of a normal (or near‐normal) glomerular filtration rate. Inborn dRTA can be due to autosomal dominant or recessive gene defects. Clinical symptoms vary from mild acidosis, incidental detection of kidney stones or renal tract calcification to severe findings such as failure to thrive, severe metabolic acidosis, and nephrocalcinosis. The majority of patients with recessive dRTA present with sensorineural hearing loss (SNHL). Few cases with abnormal widening of the vestibular aqueduct have been described with dRTA. Mutations in three different genes have been identified, namely SLC4A1, ATP6V1B1, and ATP6V0A4. Patients with mutations in the ATP6V1B1 proton pump subunit develop dRTA and in most of the cases sensorineural hearing loss early in childhood. We present two patients from two different and non‐consanguineous families with dRTA and SNHL. Direct sequencing of the ATP6V1B1 gene revealed that one patient harbors two homozygous mutations and the other one is a compound heterozygous. To our knowledge, this is the first case in the literature describing homozygosity in the same dRTA gene on both alleles.