Project description:Radiofrequency catheter ablation (RFCA) is the primary choice for treating patients with an accessory pathway and atrioventricular re-entrant tachycardia. However, using RFCA to treat a right-sided accessory pathway in a patient with Ebstein anomaly can be difficult owing to challenges in locating the electrophysiological atrioventricular groove. We report a case of atrioventricular re-entrant tachycardia in a patient with Ebstein anomaly and a right-sided accessory pathway that was successfully treated using RFCA and 3-dimensional (3D) high-density mapping. RFCA and 3D mapping may be useful in the management of such cases and may aid in improving prognoses of patients.
Project description:Proper localization of the anatomical target during ablation of the accessory pathways (AP) and the ability to detect clear AP potentials on the ablation catheter are crucial for successful AP ablation. We report a case of recurring AP conduction that was finally eliminated using a novel ablation catheter equipped with high-resolution mini-electrodes. Smaller and closer electrodes result in high mapping resolution with less signal averaging and cancellation effects. Owing to improved sensitivity, the new catheter seems effective in detecting fragmented and high frequency signals, thus allowing more effective radiofrequency application and improving ablation success.
Project description:Background:Catheter ablation (CA) of epicardial accessory pathways (APs) can be performed via the coronary sinus (CS) system. Variable CS anatomy with complications of former CA procedures inside the CS venous system may require using alternative CA approach and technology. Case summary:We report the case of a 23-year-old man with Wolff-Parkinson-White syndrome and history of aborted sudden cardiac death (SCD) and unsuccessful previous AP radiofrequency ablation (RFA). CS venography during the redo procedure revealed an early CS trifurcation with cardiac veins stenosis, thus with difficulties in maintaining cardiac veins' access and catheter manoeuvring inside CS venous system. The last office visit with electrocardiogram (ECG) performance was in 3?months after the CA. Neither delta wave on the ECG nor any complaints/adverse health effects was detected at that time. Discussion:Successful CA of epicardial AP in patients with a high risk of SCD is essential. However, CS complex anatomy and changes after former RFA inside it may lead to CS venous system access limitations. Alternative CA approach and technology should be considered to ensure CS venous system cannulation and epicardial AP CA performance.
Project description:The purpose of this study was to evaluate ultra high density-activation sequence mapping (UHD-ASM) for ablating atypical atrial flutters.For 23 patients with 31 atypical atrial flutters (AAF), we created UHD-ASM.Demographics age?=?65.3?±?8.5 years, male?=?78%, left atrial size?=?4.66?±?0.64 cm, redo ablation 20/23(87%). AAF were left atrial in 30 (97%). For each AAF, 1273?±?697 points were used for UHD-ASM. Time to create and interpret the UHD-ASM was 20?±?11 min. For every AAF, the entire circuit was identified. Thirty (97%) were macroreentry. AAF cycle length was 267?±?49 ms, and the circuit length was 138?±?38 mm (range 35-187). Macroreentry atrial flutters took varied pathways, but each had an area of slow conduction (ASC) averaging 16?±?6 mm (range 6-29) in length. Entrainment was not utilized. We targeted the ASC and ablation terminated AAF directly in 19/31 (61.3%) and altered AAF activation in 7/31 (22.6%), all of which terminated directly with additional mapping/ablation. AAF degenerated to atrial fibrillation in 2/31 (6.5%) with RF and could not be reinduced after ASC ablation. Median time from initial ablation to AAF termination was 64 s. Thus, 28/31 (90.3%) terminated with RF energy and/or could not be reinduced after ASC ablation. At 1 year of follow-up, 77% were free of atrial tachycardia or atrial flutter and 61% were free of all atrial arrhythmias.Using rapidly acquired UHD-ASM, the entire AAF circuit as well as the target ASC could be identified. Most AAF were left atrial macroreentry. Ablation of the ASC or microreentry focuses directly terminated or eliminated AAF in 90.3% without the need for entrainment mapping.
Project description:A 73-year-old woman was admitted for atrial tachycardia (AT) ablation. The activation map and pacing study indicated that the AT propagated around the left pulmonary vein and that the Marshall bundle (MB) bypassed the scar area of the left pulmonary vein ridge and mitral isthmus. The Rhythmia Mapping System revealed double potentials propagated along the assumed position of the MB. The mapping system includes a confidence mask that can be used to visually identify low-confidence areas of the map based upon extremely low-voltage signals. Given the low-voltage area in the endocardial side, the epicardial conduction was emphasized.
Project description:The intent of the experiment was to construct molecular SNP-binning markers of a Col-0 x Pat RIL population, for sensitive QTL mapping. We performed Illumina low-coverage DNA sequencing of plant tissues.
Project description:An ultra-high-speed algorithm based on Histogram of Oriented Gradient (HOG) and Support Vector Machine (SVM) for hardware implementation at 10,000 frames per second (FPS) under complex backgrounds is proposed for object detection. The algorithm is implemented on the field-programmable gate array (FPGA) in the high-speed-vision platform, in which 64 pixels are input per clock cycle. The high pixel parallelism of the vision platform limits its performance, as it is difficult to reduce the strides between detection windows below 16 pixels, thus introduce non-negligible deviation of object detection. In addition, limited by the transmission bandwidth, only one frame in every four frames can be transmitted to PC for post-processing, that is, 75% image information is wasted. To overcome the mentioned problem, a multi-frame information fusion model is proposed in this paper. Image data and synchronization signals are first regenerated according to image frame numbers. The maximum HOG feature value and corresponding coordinates of each frame are stored in the bottom of the image with that of adjacent frames'. The compensated ones will be obtained through information fusion with the confidence of continuous frames. Several experiments are conducted to demonstrate the performance of the proposed algorithm. As the evaluation result shows, the deviation is reduced with our proposed method compared with the existing one.
Project description:Arabidopsis thaliana shows a wide range of genetic and trait variation among wild accessions. Because of its unparalleled biological and genomic resources, Arabidopsis has a high potential for the identification of genes underlying ecologically important complex traits, thus providing new insights on genome evolution. Previous research suggested that distinct light responses were crucial for Arabidopsis establishment in a peculiar ecological niche of southern Patagonia. The aim of this study was to explore the genetic basis of contrasting light-associated physiological traits that may have mediated the rapid adaptation to this new environment. From a biparental cross between the photomorphogenic contrasting accessions Patagonia (Pat) and Columbia (Col-0), we generated a novel recombinant inbred line (RIL) population, which was entirely next-generation sequenced to achieve ultra-high-density saturating molecular markers resulting in supreme mapping sensitivity. We validated the quality of the RIL population by quantitative trait loci (QTL) mapping for seedling de-etiolation, finding seven QTLs for hypocotyl length in the dark and continuous blue light (Bc), continuous red light (Rc), and continuous far-red light (FRc). The most relevant QTLs, Rc1 and Bc1, were mapped close together to chromosome V; the former for Rc and Rc/dark, and the latter for Bc, FRc, and dark treatments. The additive effects of both QTLs were confirmed by independent heterogeneous inbred families (HIFs), and we explored TZP and ABA1 as potential candidate genes for Rc1 and Bc1QTLs, respectively. We conclude that the Pat × Col-0 RIL population is a valuable novel genetic resource to explore other adaptive traits in Arabidopsis.
Project description:Current serological immunoassays have inherent limitations for certain infectious diseases such as Lyme disease, a bacterial infection caused by Borrelia burgdorferi in North America. Here we report a novel method of manufacturing high-density multiplexed protein microarrays with the capacity to detect low levels of antibodies accurately from small blood volumes in a fully automated system. A panel of multiple serological markers for Lyme disease are measured using a protein microarray system, Lyme Immunochip, in a single step but interpreted adhering to the standard two-tiered testing algorithm (enzyme immunoassay followed by Western blot). Furthermore, an enhanced IgM assay was supplemented to improve the test's detection sensitivity for early Lyme disease. With a training cohort (n = 40) and a blinded validation cohort (n = 90) acquired from CDC, the Lyme Immunochip identified a higher proportion of Lyme disease patients than the two-tiered testing (82.4% vs 70.6% in the training set, 66.7% vs 60.0% in the validation set, respectively). Additionally, the Immunochip improved sensitivity to 100% while having a lower specificity of 95.2% using a set of investigational antigens which are being further evaluated with a large cohort of blinded samples from the CDC and Columbia University. This universal microarray platform provides an unprecedented opportunity to resolve a broad range of issues with diagnostic tests, including multiplexing, workflow simplicity, and reduced turnaround time and cost.