Project description:BackgroundTransseptal puncture to achieve left atrial access is necessary for many cardiac procedures, including atrial fibrillation ablation. More recently, there has been an increasing need for left atrial access using large caliber sheaths, which increases risk of perforation associated with the initial advancement into the left atrium. We compared the effectiveness of a radiofrequency needle-based transseptal system versus conventional needle for transseptal access.MethodsThis prospective controlled trial randomized 161 patients with symptomatic paroxysmal atrial fibrillation undergoing cryoballoon pulmonary vein isolation to transseptal access with a commercially available transseptal system (radiofrequency needle plus stiff pigtail wire; RF + Pigtail group) versus conventional transseptal access (standard group). The primary outcome was time required for left atrial access. Secondary outcomes included failure of the assigned transseptal system, radiation exposure, and complications.ResultsThe median transseptal puncture time was significantly shorter using the radiofrequency needle plus stiff pigtail wire transseptal system compared with conventional transseptal (840 ± 323 vs. 956 ± 407 s, P = 0.0489). Compared to conventional transseptal puncture, fewer transseptal attempts were required (1.0 ± 0.5 RF applications vs. 1.3 ± 0.8 mechanical punctures, P = 0.0123) and the fluoroscopy time was significantly shorter (72.0 [IQR 48.0, 129.0] vs. 93.0 [IQR 60.0, 171.0] s, P = 0.0490) with the radiofrequency needle plus stiff pigtail wire transseptal system. Failure to achieve transseptal LA access with the assigned system was rarely observed (1.3% vs. 5.7%, P = 0.2192). There were no procedural complications observed with either system.ConclusionsThe use of a radiofrequency needle plus stiff pigtail wire resulted in shorter time to left atrial access and reduced fluoroscopy time compared to left atrial access using conventional transseptal equipment.Trial registrationClinicalTrials.gov identifier NCT03199703.
Project description:BackgroundIn the era of fluoroless catheter ablation (CA), achieving a successful transseptal puncture (TSP) presents a significant challenge. We introduce a novel technique for zero-fluoroscopy and cost-effective needle-free TSP.Case summaryWe describe two cases where a GMS-1 guidewire (0.025 inch, pigtail configuration; Toray Medical Co., Ltd., Japan) was utilized for TSP. This technique was performed using either fluoroscopy or intracardiac echocardiography (ICE). The procedure was completed successfully in both cases, with no complications reported.ConclusionThe use of a 0.025 inch GMS-1 guidewire with an electrocautery technique enables effective transseptal puncture without the need for a needle or fluoroscopy. This novel approach offers a safe, efficient, and zero-fluoroscopic alternative for TSP.
Project description:BackgroundCryoballoon (CB) ablation is successful in eliminating atrial fibrillation (AF).PurposeThe purpose of this study was to assess procedural efficacy and safety of CB ablation performed by a newly trained operator.MethodsForty patients with documented paroxysmal AF (58 ± 11 years, 26 male) undergoing CB catheter ablation were prospectively enrolled.ResultsElectrical pulmonary vein (PV) isolation was achieved in all patients (156 PVs). The primary end point (PV isolation using CB only) was reached in 31 patients (92% PV isolation, 144/156 PVs). In the remaining 9 patients (12 PVs), additional single point cryofocal ablations were required to achieve isolation of all veins (LSPV, n = 5; LIPV, n = 3; LCPV, n = 2; RSPV, n = 1; RIPV, n = 1). There was no vascular access complication, pericardial effusion/tamponade, stroke/transient ischemic attack, phrenic nerve palsy, acute PV stenosis, or atrioesophageal fistula. The procedure duration decreased with experience by 30% from 155 min during the first 10 procedures to 108 min (final 10 treatments). Similar effects were observed with fluoroscopy time (-57%; from 28 min to 12 min), dose area product (-66%; from 22 Gy x cm2 to 8 Gy x cm2), CB time in the left atrium (-24%; from 99 min to 75 min), and cryoenergy delivery time (-19%; from 83 min to 67 min), when comparing cases #1-10 to cases #30-40.ConclusionsCB ablation of AF is effective and safe in the hands of a new operator. Procedure and fluoroscopy times decrease with user experience.
Project description:Epigenetics helps define current cell states, yet also shapes how cells respond to external cues such as differentiation or stress. The epigenetic plasticity of a cell describes how flexible this regulation is. Bivalent chromatin is an exemplar of epigenetic plasticity. This co-occurrence of the active-associated H3K4me3 and inactive-associated H3K27me3 histone modifications on opposite tails of the same nucleosome was first described in mouse embryonic stem cells where it is found at promoters of key developmental genes. It has been postulated that bivalent chromatin poises these promoters, keeping them free from repressive DNAmethylation, enabling them to be transcriptionally upregulated upon differentiation. Bivalent chromatin has also been reported in other cell types including somatic cells and cancer cells, however we know little of the dynamics, resolution and regulation of this chromatin state. This is partly due to the technical challenges distinguishing bone-fide bivalent chromatin, where both marks are on the same nucleosome, from sample heterogeneity where some alleles have H3K4me3 and others H3K27me3. We developed a robust and sensitive reChIP method to accurately profile bivalent chromatin in as little as 2 million mouse embryonic stem cells. We validated the sensitivity of our method to detect changes in bivalent chromatin by profiling mouse ESCs lacking the epigenetic priming factors Dppa2 and Dppa4.
Project description:BackgroundThe non-fluoroscopy approach with the use of a three-dimensional (3D) navigation system is increasingly recognized as a future technology in the treatment of arrhythmias. However, there are a limited number of articles published concerning transseptal puncture without the use of fluoroscopy.MethodsPresented in this paper is the first series of patients (n = 10) that have undergone transseptal puncture without the use of fluoroscopy under transesophageal echocardiography control using a radiofrequency transseptal needle and a 3D navigation system.ResultsAll patients were treated without complications. In 6 patients, re-pulmonary vein isolation was performed. In 5 cases, linear ablation of the left atrium for treatment of left atrial macro re-entry tachycardia was provided. In 2 patients, focal atrial tachycardia was treated, 1 patient underwent cavo tricuspidal isthmus (CTI) ablation and 1 patient, re-CTI ablation. The ablation of complex fragmented atrial electrograms was done in 2 patients. In 1 case, right atrial macro re-entry tachycardia was treated.ConclusionsTransseptal puncture without using fluoroscopy is safe and effective when using a radiofrequency needle, a 3D navigation system and transesophageal echocardiography.
Project description:IntroductionOptimal occlusion of pulmonary vein (PV) is essential for atrial fibrillation (AF) cryoballoon ablation (CBA). The aim of the study was to investigate the performance of two different tools for the assessment of PV occlusion with a novel navigation system in CBA procedure.MethodsIn consecutive patients with paroxysmal AF who underwent CBA procedure with the guidance of the novel 3-dimentional mapping system, the baseline tool, injection tool and pulmonary venography were all employed to assess the degree of PV occlusion, and the corresponding cryoablation parameters were recorded.ResultsIn 23 patients (mean age 60.0 ± 13.9 years, 56.5% male), a total of 149 attempts of occlusion and 122 cryoablations in 92 PVs were performed. Using pulmonary venography as the gold standard, the overall sensitivity, specificity of the baseline tool was 96.7% (95% confidence interval [CI] 90.0%-99.1%), and 40.5% (95% CI 26.0%-56.7%), respectively, while the corresponding value of the injection tool was 69.6% (95% CI 59.7%-78.1%), and 100.0% (95% CI 90.6%-100.0%), respectively. Cryoablation with optimal occlusion showed lower nadir temperature (baseline tool: -44.3 ± 8.4°C vs. -35.1 ± 6.5°C, p < .001; injection tool: -46.7 ± 6.4°C vs. -38.3 ± 9.2°C, p < .001) and longer total thaw time (baseline tool: 53.3 ± 17.0 s vs. 38.2 ± 14.9 s, p = .003; injection tool: 58.5 ± 15.5 s vs. 41.7 ± 15.2 s, p < .001) compared with those without.ConclusionsBoth tools were able to accurately assess the degree of PV occlusion and predict the acute cryoablation effect, with the baseline tool being more sensitive and the injection tool more specific.
Project description:PurposeThe aim was to report procedural and technical differences of a novel cryoballoon (NCB) ablation catheter for pulmonary vein isolation (PVI) compared to the standard cryoballoon (SCB) catheter.MethodsConsecutive patients with atrial fibrillation (AF) undergoing PVI using the NCB and the SCB were included. Procedural parameters, technical differences, acute efficacy, and safety are reported.ResultsEighty patients (age 66 ± 10 years, ejection fraction 57 ± 10%, left atrial volume index 40 ± 6 ml/m2) were studied. With the NCB, 156 of 158 PVs (99%) were isolated compared to isolation of 159 of 159 PVs (100%) with the SCB. The median number of freezes in the NCB and the SCB group was 6 (IQR 5-8) and 5 (IQR 4-7), respectively (p = 0.051), with 73% and 71% of the PVs isolated with a single freeze, respectively. Nadir temperature and temperature at isolation were - 59 ± 6 °C and - 45 ± 17 °C in the NCB group and - 46 ± 7 °C and - 32 ± 23 °C in the SCB group, respectively (both p < 0.001) with no difference in time to isolation (TTI). Procedural differences were observed for the total procedure time (84 ± 29 min in the NCB group and 65 ± 17 min in the SCB group, p = 0.003). There was a peri-procedural stroke in one patient in the NCB group. Differences in catheter design were observed that may account for the differences in temperature recordings and ice cap formation.ConclusionsAcute efficacy and TTI were similar with the NCB compared to the SCB. Measured temperatures were lower with the NCB, most likely due to differences in catheter design.