Ablação por cateter versus tratamento farmacológico para pacientes com síndrome de Wolf-Parkinson-White: revisão sistemática

Pós-graduação em Bases Gerais da Cirurgia - FMB

Paraseptal accessory pathway in Wolff-Parkinson- White-Syndrom: ablation from the right, from the left or within the coronary sinus/middle cardiac vein?

AIMS In 1999 the consensus statement "living anatomy of the atrioventricular junctions" was published. With that new nomenclature the former posteroseptal accessory pathway (APs) are termed paraseptal APs. The aim of this study was to identify ECG features of manifest APs located in this complex paraseptal space. METHODS AND RESULTS ECG characteristics of all patients who underwent radiofrequency ablation of an AP during a 3 year period were analyzed. Of the 239 patients with one or more APs, 30 patients had a paraseptal AP with preexcitation. Compared to APs within the coronary sinus (CS) or the middle cardiac vein (MCV) the right sided paraseptal APs significantly more often showed an isoelectric delta wave in lead II and/or a negative delta wave in aVR. The left sided paraseptal APs presented a negative delta wave in II significantly more often compared to the right sided APs. CONCLUSIONS According to the site of radiofrequency ablation, paraseptal APs are classified into 4 subgroups: paraseptal right, paraseptal left, inside the CS or inside the MCV. Subtle differences in preexcitation patterns of the delta wave as well as of the QRS complex exist. However, the definitive localization of APs remains reserved to the periinterventional intracardiac electrogram analysis.

Importância do eletrocardiograma de doze derivações na localização da via acessória no padrão de Wolff-Parkinson-White

A ablação por cateter de radiofrequência tornou-se o tratamento de escolha para os pacientes com síndrome de Wolff-Parkinson-White, sintomáticos. A localização da via acessória a partir da morfologia do QRS no eletrocardiograma basal, torna-se útil para o planeamento do procedimento de ablação, por permitir um conjunto de informações que ajudam na escolha da melhor abordagem terapêutica, em particular no que respeita ao intervalo para a ablação, a necessidade de punção transeptal e o risco de bloqueio aurículo-ventricular, se a via acessória estiver próxima do nódulo aurículo-ventricular ou do feixe de His. Estão descritos vários algoritmos para prever a localização da via acessória a partir da análise da morfologia do QRS basal. Os seus autores relatam elevados índices de acerto, todavia, estudos subsequentes obtiveram resultados distintos, com índices de acerto menores. O presente estudo tem como objetivo principal a avaliação da capacidade diagnóstica do eletrocardiograma de doze derivações na localização da via acessória no padrão de Wolff- Parkinson-White. Os dados clínicos necessários a este estudo foram recolhidos no Serviço de Cardiologia do Centro Hospitalar S. João – EPE, através da consulta dos exames eletrocardiograma e estudo eletrofisiológico, nos indivíduos com diagnóstico prévio de síndrome de Wolff-Parkinson- White. Numa amostra formada por 111 indivíduos de ambos os géneros e com idade média de 36,54 (± 15,27) anos (idade mínima de 7 anos e idade máxima de 75 anos), procedeu-se à comparação da localização da via acessória no estudo eletrofisiológico, com a obtida pela aplicação dos algoritmos de Arruda et al., Boersma et al., Chiang et al., Ávila et al., Fitzpatrick et al., Iturralde et al. e Xie et al. (harmonizadas para todos os algoritmos, as localizações possíveis das vias acessórias). Em volta do anel mitral, encontravam-se distribuídas 59 vias acessórias (53,15%), sendo 52 as vias acessorias distribuídas em torno do anel tricúspide (46,85%). Nesta distribuição não se observaram diferenças estatisticamente significativas de acordo com o género. O acerto global em todos os algoritmos variou entre 27,00% a 47,00%, aumentando para 40,00% a 76,00%, incluindo as localizações adjacentes. A concordância entre os investigadores variou entre 40,00% a 80,00%, observando-se que em relação ao valor médio de concordância, os algoritmos com menores localizações possíveis para as vias acessórias, obtiveram melhor resultado (64,00%). O acerto para as vias acessórias septais (51 no total) variou entre 2,00% a 52,20% (aumentando para 5,90% a 90,20%, incluindo as localizações adjacentes). As vias acessórias direitas, 13 no total, obtiveram acerto entre 7,70% a 69,20% (aumentando para 42,90% a 100%, incluindo as vias acessórias adjacentes). Por último, as vias acessórios esquerdas, 47 no total, obtiveram acerto entre 21,70% a 54,50% (aumentando para 50,00% a 87,00%, incluindo as vias acessórias adjacentes). Para esta distribuição das vias acessórias (localização septal, direita e esquerda), não se observaram diferenças estatisticamente significativas, de acordo com o género. Os resultados obtidos revelam que todos os algoritmos obtiveram valores de acerto inferiores aos enunciados pelos seus autores, permitindo concluir que embora o eletrocardiograma constitua um método muito importante no diagnóstico da pré-excitação ventricular do tipo Wolff-Parkinson-White, este não é sensível, nem específico para a deteção da localização da via acessória.

Radiofrequency ablation of multiple accessory pathways

The aim of the study was to review the clinical and electrophysiological characteristics and results of radiofrequency catheter ablation in patients with multiple accessory pathways to compare them with those of patients with single accessory pathways. Electrophysiological study and radiofrequency catheter ablation were performed in 1010 consecutive cases with Wolff Parkinson White Syndrome. Presence of multiple accessory pathways was documented in 31 patients (3.1%); 30 had two, and 1 had three accessory pathways. Of the 63 accessory pathways, 42 were manifest and 21 concealed. Nine patients had Ebstein's anomaly associated with atrioventricular bypass tracts. The most common combination was right posteroseptal with right free wall bypass tracts (15 patients with 30 accessory pathways). Fifty-one of the sixty-three accessory pathways (81%) were ablated successfully without complications. The duration of the procedure was 100 +/- 58 min and the fluoroscopic time 40 +/- 17 min. A follow up of 5 +/- 3 years after ablation, demonstrated recurrences of six accessory pathways (9.5%). In conclusion, patients with multiple accessory pathways can be treated by radiofrequency ablation in only one session with a high success rate although slightly less than that in patients with a single accessory pathway (81% vs 93%, P<0.01).

Microbial Communities Associated with Healthy and White Syndrome-Affected Echinopora lamellosa in Aquaria and Experimental Treatment with the Antibiotic Ampicillin

Prokaryotic and ciliate communities of healthy and aquarium White Syndrome (WS)-affected coral fragments were screened using denaturing gradient gel electrophoresis (DGGE). A significant difference (R = 0.907, p < 0.001) in 16S rRNA prokaryotic diversity was found between healthy (H), sloughed tissue (ST), WS-affected (WSU) and antibiotic treated (WST) samples. Although 3 Vibrio spp were found inWS-affected samples, two of these species were eliminated following ampicillin treatment, yet lesions continued to advance, suggesting they play a minor or secondary role in the pathogenesis. The third Vibrio sp increased slightly in relative abundance in diseased samples and was abundant in non-diseased samples. Interestingly, a Tenacibaculum sp showed the greatest increase in relative abundance between healthy and WS-affected samples, demonstrating consistently high abundance across all WS-affected and treated samples, suggesting Tenacibaculum sp could be a more likely candidate for pathogenesis in this instance. In contrast to previous studies bacterial abundance did not vary significantly (ANOVA, F2, 6 = 1.000, p = 0.422) between H, ST, WSU or WST. Antimicrobial activity (assessed on Vibrio harveyi cultures) was limited in both H and WSU samples (8.1% ±8.2 and 8.0% ±2.5, respectively) and did not differ significantly (Kruskal-Wallis, χ2 (2) = 3.842, p = 0.146). A Philaster sp, a Cohnilembus sp and a Pseudokeronopsis sp. were present in all WS-affected samples, but not in healthy samples. The exact role of ciliates in WS is yet to be determined, but it is proposed that they are at least responsible for the neat lesion boundary observed in the disease.

Intra-colonial response to Acroporid "White syndrome" lesions in tabular Acropora spp. (Scleractinia)

'White syndrome' is considered to be the most prevalent coral disease on the Great Barrier Reef, characterised by rapid rates of lesion progression and high levels of colony mortality. This study investigated the production and translocation of photoassimilates towards white syndrome lesions (WSLs) and artificially inflicted lesions in healthy and diseased colonies of tabular Acropora spp. to determine the intra-colonial response to white syndrome using C-14 labelling. Translocation of C-14 labelled photoassimilates was preferentially orientated away from active WSLs, with minimal C-14 activity observed in the lesion borders, whilst artificial lesions (ALs) created directly opposite WSL borders showed significantly higher C-14 activity, suggesting active translocation of photoassimilates for tissue regeneration. Transport of photoassimilates in healthy coral colonies was preferentially oriented towards ALs with a higher perimeter-area ratio, although translocation towards WSL boundaries was minimal even though the lesion perimeter was often the width of the colony (> 200 cm). We suggest that the preferential orientation of photoassimilates away from WSLs may represent a deliberate strategy by the colony to induce a 'shutdown reaction' in order to preserve intra-colonial resources within areas of the colony that are more likely to survive and recover.

Phototrophic microendoliths bloom during coral "white syndrome"

Following rapid lesion progression of white syndrome in tabular Acropora spp., the white bare skeleton gradually changes to green, a result of endolithic algae blooms (primarily Ostreobium spp.). Endolithic algal biomass and chlorophyll concentration were found to be an order of magnitude higher in the green zone compared with healthy appearing parts of each colony. Chl b to Chl a ratio increased from 1:1.6 in the healthy area to 1:2 and 1:3.5 in the white exposed skeleton and green zones, respectively. These observations together with pulse amplitude modulated (PAM) fluorometry suggest photoacclimation of the endoliths in the green zone. Histopathological microscopy revealed that the endolithic algal filaments penetrate the coral tissue. This study highlights the interaction of endolithic algae with both the skeleton and host tissue. This may have a critical role in the processes that accompany the post-disease state in reef-building corals.

Microbial community analysis of Acropora palamata mucus swabs, water and sediment samples from Hawksnest Bay, St. John, U.S. Virgin Islands

Colonies of the scleractinian coral Acropora palmata, listed as threatened under the US Endangered Species Act in 2006, have been monitored in Hawksnest Bay, within Virgin Islands National Park, St. John, from 2004 through 2010 by scientists with the US Geological Survey, National Park Service, and the University of the Virgin Islands. The focus has been on documenting the prevalence of disease, including white band, white pox (also called patchy necrosis and white patches), and unidentified diseases (Rogers et al., 2008; Muller et al., 2008). In an effort to learn more about the pathologies that might be involved with the diseases that were observed, samples were collected from apparently healthy and diseased colonies in July 2009 for analysis. Two different microbial assays were performed on Epicentre Biotechnologies DNA swabs containing A. palmata coral mucus, and on water and sediment samples collected in Hawksnest Bay. Both assays are based on polymerase chain reaction (PCR) amplification of portions of the small rRNA gene (16S). The objectives were to determine 1) if known coral bacterial pathogens Serratia marcescens (Acroporid Serratiosis), Vibrio coralliilyticus (temperature-dependent bleaching, White Syndrome), Vibrio shiloi (bleaching, necrosis), and Aurantimonas coralicida (White Plague Type II) were present in any samples, and 2) if there were any differences in microbial community profiles of each healthy, unaffected or diseased coral mucus swab. In addition to coral mucus, water and sediment samples were included to show ambient microbial populations. In the first test, PCR was used to separately amplify the unique and diagnostic region of the 16S rRNA gene for each of the coral pathogens being screened. Each pathogen test was designed so that an amplified DNA fragment could be seen only if the specific pathogen was present in a sample. A positive result was indicated by bands of DNA of the appropriate size on an agarose gel, which separates DNA fragments based on the size of the molecule. DNA from pure cultures of each of the pathogens was used as a positive control for each assay.

3-D Technology Used to Accurately Understand Equine Ileocolonic Aganglionosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

White spot syndrome virus (WSSV) transmission risk through infected cooked shrimp products assessed by polymerase chain reaction (PCR) and bio-inoculation studies

The aim of the study was to evaluate the resistance of white spot syndrome virus (WSSV) in shrimps (Penaeus monodon) to the process of cooking. The cooking was carried out at 1000C six different durations 5, 10, 15, 20, 25 and 30 min. The presence of WSSV was tested by single step and nested polymerase chain reaction (PCR). In the single step PCR, the primers 1s5 & 1a16 and IK1 & IK2 were used. While in the nested PCR, primers IK1 &IK2 – IK3 & IK4 were used for the detection of WSSV. WSSV was detected in the single step PCR with the primers 1s5 and 1a16 and the nested PCR with the primers IK1 and IK2 – IK3 & IK4 from the cooked shrimp samples. The cooked shrimps, which gave positive results for WSSV by PCR, were further confirmed for the viability of WSSV by conducting the bio-inoculation studies. Mortality (100%) was observed within 123 h of intra-muscular post injection (P.I) into the live healthy WSSV-free shrimps (P. monodon). These results show that the WSSV survive the cooking process and even infected cooked shrimp products may pose a transmission risk for WSSV to the native shrimp farming systems.

Rapid detection of white spot syndrome virus (WSSV) of Penaeus monodon by latex agglutination test using monoclonal antibodies

Latex beads were sensitized with monoclonal antibodies (MAb) rose against VP28 of WSSV. The optimum concentration of MAb required to sensitize the latex beads was 125 µg/ml. The sensitized latex beads were used to detect WSSV from PCR-positive stomach tissue homogenates obtained from infected shrimp. Stomach tissue homogenates from WSSV-infected shrimp agglutinated the sensitized latex beads within 10 minutes, while uninfected samples did not produce any agglutination, although non-specific agglutinations were observed in some samples. The analytical sensitivity, analytical specificity, diagnostic sensitivity and diagnostic specificity of the (LAT) agglutination test were assessed. The analytical sensitivity of the test was 40 ng of purified WSSV (2 µg/ml). The sensitized latex beads did not agglutinate with normal shrimp tissue or MBV-infected tissue homogenate. The test has a diagnostic sensitivity of 70 and 45%, respectively, compared to single-step and nested PCR. The diagnostic specificity of the test was 82%. This test is a simple and rapid on-farm test which can be used to corroborate clinical signs for the detection of WSSV in grow-out ponds.