148 research outputs found
Forceâsensing catheters during pediatric radiofrequency ablation: The FEDERATION Study
Background
Based on data from studies of atrial fibrillation ablations, optimal parameters for the TactiCath (TC; St. Jude Medical, Inc) forceâsensing ablation catheter are a contact force of 20 g and a forceâtime integral of 400 g·s for the creation of transmural lesions. We aimed to evaluate TC in pediatric and congenital heart disease patients undergoing ablation.
Methods and Results
Comprehensive chart and case reviews were performed from June 2015 to March 2016. Of the 102 patients undergoing electrophysiology study plus ablation, 58 (57%) underwent ablation initially with a forceâsensing catheter. Patients had an average age of 14 (2.4â23) years and weight of 58 (18â195) kg with 15 patients having abnormal cardiac anatomy. Electrophysiology diagnoses for the +
TC
group included 30 accessory pathwayâmediated tachycardia, 24 atrioventricular nodal reentrant tachycardia, and 7 other. Baseline generator settings included a power of 20 W, temperature of 40°, and 6 cc/min flow during lesion creation with 11 patients (19%) having alterations to parameters. Seventeen patients (30%) converted to an alternate ablation source. A total of 516 lesions were performed using the
TC
with a median contact force of 6 g, forceâtime integral of 149 g·s, and lesion size index of 3.3. Medianâterm followâup demonstrated 5 (10%) recurrences with no acute or medianâterm complications.
Conclusions
TactiCath can be effectively employed in the treatment of pediatric patients with congenital heart disease with lower forces than previously described in the atrial fibrillation literature. Patients with atrioventricular nodal reentrant tachycardia or atrioventricular reciprocating tachycardia may not require transmural lesions and the
TC
may provide surrogate markers for success during slow pathway ablation.
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Giant Left Atrial Myxoma Masquerading as Cough-Syncope Syndrome
Left atrial myxomas are the most common type of benign primary cardiac tumor. Patients can present with generalized symptoms, such as fatigue, symptoms from obstruction of the myxoma, or even embolization of the myxoma causing distal thrombosis. We describe a case with several-month duration of syncopal episodes that occurred after coughing and with exertion. Computed tomography of the chest showed a 6.1 cm by 4.5 cm mass in the left atrium, later evaluated with an echocardiogram. Cardiothoracic surgery removed the mass, and it was determined to be an atrial myxoma. It is important for an internist to be able to diagnose an atrial myxoma because of the risks associated with embolization and even sudden death as myxoma can block blood supply from atrium to ventricle
High-Output Heart Failure Contributing to Recurrent Epistaxis Kiesselbach Area Syndrome in a Patient With Hereditary Hemorrhagic Telangiectasia
Hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu syndrome, is a rare genetic blood disorder that leads to abnormal bleeding due to absent capillaries and multiple abnormal blood vessels known as arteriovenous malformations. A feature of HHT is high-output heart failure due to multiple arteriovenous malformations. High-output heart failure can lead to recurrent epistaxis Kiesselbach area syndrome (REKAS), further exacerbating heart failure through increased blood loss and resultant anemia. We report a patient with HHT who presented with high-output heart failure contributing to REKAS. In patients with REKAS, we propose if anemia is present, REKAS can be avoided by correcting the anemia by increasing the hemoglobin level to greater than 9 to 10 g/dL. This decreases hyperdynamic circulation and reduces pressure in the blood vessels of the nose
Implantable loop recorder monitoring for refining management of children with inherited arrhythmia syndromes
BACKGROUND: Implantable loop recorders (ILRs) are conventionally utilized to elucidate the mechanism of atypical syncope. The objective of this study was to assess the impact of these devices on management of pediatric patients with known or suspected inherited arrhythmia syndromes. METHODS AND RESULTS: A retrospective chart review was undertaken of all pediatric patients with known or suspected inherited arrhythmia syndromes in whom an ILR was implanted from 2008 to 2015. Captured data included categorization of diagnosis, treatment, transmitted tracings, and the impact of ILR tracings on management. Transmissions were categorized as symptomatic, autotriggered, or routine. Actionable transmissions were abnormal tracings that directly resulted in a change of medical or device therapy. A total of 20 patients met the stated inclusion criteria (long QT syndrome, n=8, catecholaminergic polymorphic ventricular tachycardia,n=9, Brugada syndrome, n=1, arrhythmogenic right ventricular cardiomyopathy, n=2), with 60% of patients being genotype positive. Primary indication for implantation of ILR included ongoing monitoring +/â symptoms (n=15, 75%), suspicion of noncompliance (n=1, 5%), and liberalization of recommended activity restrictions (n=4, 25%). A total of 172 transmissions were received in patients with inherited arrhythmia syndromes, with 7% yielding actionable data. The majority (52%) of symptom events were documented in the long QT syndrome population, with only 1 tracing (5%) yielding actionable data. Automatic transmissions were mostly seen in the catecholaminergic polymorphic ventricular tachycardia cohort (81%), with 21% yielding actionable data. There was no actionable data in routine transmissions. CONCLUSIONS: ILRs in patients with suspected or confirmed inherited arrhythmia syndromes may be useful for guiding management. Findings escalated therapies in 30% of subjects. As importantly, in this highârisk population, the majority of symptom events represented normal or benign rhythms, reassuring patients and physicians that no further intervention was required
Observations from a systematic review of pharmacist- led research in solid organ transplantation: An opinion paper of the American College of Clinical Pharmacy Immunology/Transplantation Practice and Research Network
IntroductionThe contributions of transplant pharmacists to clinical and translational research in the United States are ill- defined and have not been systematically reviewed.ObjectivesThe American College of Clinical Pharmacy Immunology/Transplantation Practice and Research Network conducted a systematic review of available pharmacist- led research publications involving solid organ transplantation with the intent to quantify and describe pharmacist- led research endeavors and their changes over time.MethodsAn electronic search of Scopus was conducted to identify publications in the field of solid organ transplantation by pharmacist authors between January 1, 1975 and May 25, 2017. Articles were excluded if they were written in non- English languages or originated from non- US countries. Review articles, case reports, surveys, basic science research, pre- clinical studies, and non- transplant research were further excluded. Studies were categorized as one of four phases on the clinical and translational research spectrum, adapted from the Harvard Clinical and Translational Science Center description of a T1 to T4 classification system.ResultsA total of 10- 354 publications were identified by the systematic search with 547 full- text English- language publications included in the analysis. Pharmacists served as the first author in 87% of the articles and as the senior author in 67% of the articles. A total of 71% of the articles included more than one pharmacist author. Transplant pharmacists published more studies that employed a retrospective or observational study design (55% and 78%, respectively). A total of 37% of studies were funded. On the spectrum of clinical and translation research, pharmacists were most involved in T3 (translation to practice) research (72%), followed by T2 (translation to patients) research (23%).ConclusionsTransplant pharmacists are increasingly represented in the US literature and frequently published across domains. Further demonstrating the relevance of pharmacist- delivered interventions and outcomes is a critical area of practice focus.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163590/2/jac51294.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163590/1/jac51294_am.pd
Histone locus regulation by the Drosophila dosage compensation adaptor protein CLAMP
The conserved histone locus body (HLB) assembles prior to zygotic gene activation early during development and concentrates factors into a nuclear domain of coordinated histone gene regulation. Although HLBs form specifically at replication-dependent histone loci, the cis and trans factors that target HLB components to histone genes remained unknown. Here we report that conserved GA repeat cis elements within the bidirectional histone3âhistone4 promoter direct HLB formation in Drosophila. In addition, the CLAMP (chromatin-linked adaptor for male-specific lethal [MSL] proteins) zinc finger protein binds these GA repeat motifs, increases chromatin accessibility, enhances histone gene transcription, and promotes HLB formation. We demonstrated previously that CLAMP also promotes the formation of another domain of coordinated gene regulation: the dosage-compensated male X chromosome. Therefore, CLAMP binding to GA repeat motifs promotes the formation of two distinct domains of coordinated gene activation located at different places in the genome
Lineage Regulators Direct BMP and Wnt Pathways to Cell-Specific Programs during Differentiation and Regeneration
SummaryBMP and Wnt signaling pathways control essential cellular responses through activation of the transcription factors SMAD (BMP) and TCF (Wnt). Here, we show that regeneration of hematopoietic lineages following acute injury depends on the activation of each of these signaling pathways to induce expression of key blood genes. Both SMAD1 and TCF7L2 co-occupy sites with master regulators adjacent to hematopoietic genes. In addition, both SMAD1 and TCF7L2 follow the binding of the predominant lineage regulator during differentiation from multipotent hematopoietic progenitor cells to erythroid cells. Furthermore, induction of the myeloid lineage regulator C/EBPα in erythroid cells shifts binding of SMAD1 to sites newly occupied by C/EBPα, whereas expression of the erythroid regulator GATA1 directs SMAD1 loss on nonerythroid targets. We conclude that the regenerative response mediated by BMP and Wnt signaling pathways is coupled with the lineage master regulators to control the gene programs defining cellular identity
Modern microwave methods in solid state inorganic materials chemistry: from fundamentals to manufacturing
No abstract available
Detection of Artificially Generated Seismic Signals Using Balloon-Borne Infrasound Sensors
Abstract We conducted an experiment in Pahrump, Nevada, in June 2017, where artificial seismic signals were created using a seismic hammer, and the possibility of detecting them from their acoustic signature was examined. In this work, we analyze the pressure signals recorded by highly sensitive barometers deployed on the ground and on tethers suspended from balloons. Our signal processing results show that wind noise experienced by a barometer on a free-flying balloon is lower compared to one on a moored balloon. This has never been experimentally demonstrated in the lower troposphere. While seismoacoustic signals were not recorded on the hot air balloon platform owing to operational challenges, we demonstrate the detection of seismoacoustic signals on our moored balloon platform. Our results have important implications for performing seismology in harsh surface environments such as Venus through atmospheric remote sensing
Pan-cancer Alterations of the MYC Oncogene and Its Proximal Network across the Cancer Genome Atlas
Although theMYConcogene has been implicated incancer, a systematic assessment of alterations ofMYC, related transcription factors, and co-regulatoryproteins, forming the proximal MYC network (PMN),across human cancers is lacking. Using computa-tional approaches, we define genomic and proteo-mic features associated with MYC and the PMNacross the 33 cancers of The Cancer Genome Atlas.Pan-cancer, 28% of all samples had at least one ofthe MYC paralogs amplified. In contrast, the MYCantagonists MGA and MNT were the most frequentlymutated or deleted members, proposing a roleas tumor suppressors.MYCalterations were mutu-ally exclusive withPIK3CA,PTEN,APC,orBRAFalterations, suggesting that MYC is a distinct onco-genic driver. Expression analysis revealed MYC-associated pathways in tumor subtypes, such asimmune response and growth factor signaling; chro-matin, translation, and DNA replication/repair wereconserved pan-cancer. This analysis reveals insightsinto MYC biology and is a reference for biomarkersand therapeutics for cancers with alterations ofMYC or the PMN
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