Blocking Rate Research Articles

Innovative water rates as a policy tool for drought response: Two case studies from Utah, USA

Drought in the Western U.S. has elevated the need for innovative water pricing. We describe two utilities whose novel pricing structures reflect water availability and reasonable use expectations. One has a physical basis of water rights, landscape water needs, and irrigated area; the other has a hydrologic basis of an annual water supply forecast. Both utilities charge users tiered (increasing block) rates for an adjustable water allotment. The rates have proved hydrologically beneficial, socially equitable, and financially sustainable during the drought, suggesting that water pricing can be an effective policy tool for responsive water management.

Ahmed and Baerveldt Glaucoma Drainage Devices in Childhood Glaucoma: A Meta-Analysis.

The effectiveness of Ahmed glaucoma valve (AGV) and Baerveldt glaucoma implant (BGI) was comparable in the management of childhood glaucoma over the long term despite initial better success rate with BGI. There were higher tube block and retraction rates in the BGI group and higher tube exposure rates in the AGV group. To evaluate the outcomes and safety of AGV and BGI in childhood glaucoma. We performed a systematic literature review of publications from 1990 to 2022 in PubMed, EMBASE, ClinicalTrials.gov, Ovid MEDLINE, Cochrane CENTRAL, and google scholar for studies evaluating AGV and BGI in childhood glaucoma. Primary outcome measures were intraocular pressure (IOP) reduction and glaucoma medication reduction. The secondary outcome measures were the success rates and incidence of postoperative complications. We conducted a meta-analysis using a random effects model. Thirty-two studies met the inclusion criteria. A total of 1480 eyes were included. The mean IOP reduction was 15.08 mm Hg ( P < 0.00001) for AGV and 14.62 ( P < 0.00001) for the BGI group. The mean difference between pre and postoperative glaucoma medications was 1 ( P < 0.00001) fewer medications in the AGV group and 0.95 ( P < 0.0001) fewer medications in the BGI group. There was a lower success rate in the AGV versus BGI groups at 2 years [63% vs 83%, respectively ( P < 0.0001) and 3 years (43% vs 79%, respectively ( P < 0.0001)]; however, the success was higher for AGV at 5 years (63% vs 56% in the BGI group, P < 0.001). The incidence of postoperative complications was comparable in the AGV and BGI groups, with rates of 28% and 27%, respectively. The IOP and glaucoma medication reduction, success rates, and incidence of postoperative complications were comparable in Ahmed and Baerveldt groups. Most literature comes from retrospective low-quality studies on refractory childhood glaucoma. Further larger cohort studies are needed.

Investigating the effect of preformed particle gel on conformance control of naturally fractured tight sandstone reservoirs: An experimental study using pressure transfer test method

The recovery of oil and gas resources is limited by the high water production from wells in unconventional reservoirs. While water intrusion prevention measures have been extensively investigated in highly permeable reservoirs, there has been limited research in tight unconventional reservoirs. In this study, a Pressure Transfer Test (PTT) method was used to evaluate the effect of preformed particle gel (PPG) on the conformance control of naturally fractured tight sandstone reservoirs. The study analyzed and compared four types of naturally fractured cores, and performed experiments on the PPG plugging effect under different natural fracture types, injection pressures, and salinities using a PTT device. The results showed that among the four fracture types, vertical and oblique penetrations had the highest plugging effect, with a 12% higher rate than fractures without effective channels. The injection pressure also had a significant impact on the plugging efficiency, with a 99.13% blocking rate at 12.5 MPa, which was almost completely plugged. Meanwhile, the salinity of the injected fluid had a decreasing effect on the PPG plugging efficiency, with the lower salinity of 1 wt% improving the plugging efficiency by 15% compared to high salinity. The experimental results and analysis were used to propose the plugging mechanism of PPG in different types of naturally fractured tight reservoirs. This study provides valuable experimental and theoretical references for the field application and further studies of PPG in naturally fractured tight reservoirs.

Cardiovascular events after the initiation of immune checkpoint inhibitors

We sought to clarify the incidence of major adverse cardiac events (MACE) after the initiation of immune checkpoint inhibitors (ICIs). We analyzed the JMDC Claims Database between 2005 and 2021. The study included 2972 patients with no history of cardiovascular disease and a prescription for an ICI. The primary outcome was the incidence of MACE, including myocarditis, pericarditis, Takotsubo cardiomyopathy, atrio-ventricular block, heart failure, myocardial infarction, and stroke. The median age of study participants was 59 (Q1-Q3 53–65) years, and 2163 participants (72.8%) were male. Lung cancer was the most common cancer site (n = 1603). Among ICIs, programmed cell death-1 (PD-1) was most frequently used, and a combination ICI treatment was conducted in 110 patients (3.7%). During a mean follow-up of 358 ± 327 days, 419 MACE events were recorded. The incidence rate of myocarditis, pericarditis, Takotsubo cardiomyopathy, atrio-ventricular block, heart failure, myocardial infarction, and stroke was 3.4, 142.3, 10.3, 17.2, 1191.2, 55.2, and 278.5 per 10,000 person-years, respectively. The incidence of cardiovascular events was higher within 180 days after the initial prescription of ICI. The continuation rate of ICI after MACE was 38.4%. In conclusion, our analysis of a nationwide epidemiological dataset demonstrated the incidence of MACE after the initiation of ICI treatment. The incidence of heart failure was higher than expected, and the continuation rate of ICI treatment after MACE was low. Our results indicated the importance of monitoring and prevention of cardiovascular events in cancer patients requiring ICI treatment.

Improving generalization performance of electrocardiogram classification models

Objective. Recently, many electrocardiogram (ECG) classification algorithms using deep learning have been proposed. Because the ECG characteristics vary across datasets owing to variations in factors such as recorded hospitals and the race of participants, the model needs to have a consistently high generalization performance across datasets. In this study, as part of the PhysioNet/Computing in Cardiology Challenge (PhysioNet Challenge) 2021, we present a model to classify cardiac abnormalities from the 12- and the reduced-lead ECGs. Approach. To improve the generalization performance of our earlier proposed model, we adopted a practical suite of techniques, i.e. constant-weighted cross-entropy loss, additional features, mixup augmentation, squeeze/excitation block, and OneCycle learning rate scheduler. We evaluated its generalization performance using the leave-one-dataset-out cross-validation setting. Furthermore, we demonstrate that the knowledge distillation from the 12-lead and large-teacher models improved the performance of the reduced-lead and small-student models. Main results. With the proposed model, our DSAIL SNU team has received Challenge scores of 0.55, 0.58, 0.58, 0.57, and 0.57 (ranked 2nd, 1st, 1st, 2nd, and 2nd of 39 teams) for the 12-, 6-, 4-, 3-, and 2-lead versions of the hidden test set, respectively. Significance. The proposed model achieved a higher generalization performance over six different hidden test datasets than the one we submitted to the PhysioNet Challenge 2020.

HOUSEHOLD-SPECIFIC SOCIAL NORMS, THE ELASTICITY OF ELECTRICITY DEMAND, AND CARBON EMISSION REDUCTIONS IN THE RESIDENTIAL SECTOR: EVIDENCE FROM A NATURAL EXPERIMENT IN RUSSIA

In this paper, I estimate the price elasticity of residential electricity demand using household-level panel data for Russia. The study takes advantage of the variation in tariffs across regions and over time, as well as the introduction of increasing block rate (IBR) schemes in a number of regions. I show that in those regions consumers appear to be aware of the block cut-offs, even though the latter are based on the prescribed social norms and are household and dwelling specific, to the point that there are up to a total of 31 different tier cut-offs. Based on these results, I estimate the price elasticity of electricity demand to be around −0.1. I also predict the associated changes in electricity consumption, CO2 emissions, and revenues if similar IBR policies are implemented countrywide.

The influence of flexible/rigid obstacle on flame propagation and blast injuries risk in gas explosion

ABSTRACT The interaction between flame, shock wave and obstacle is an important content in the study of fuel combustion and safety. In this paper, the performance difference between flexible and rigid obstacles in the process of explosion flame propagation was studied. Five barriers with different blocking rates（BR） were tested in the pipeline for methane premixed explosion. The high-speed photography system collects the flame image, the flame front velocity is calculated, and the dynamic pressure changes in the upstream and downstream pipelines during flame propagation are recorded by the high-frequency pressure acquisition system. The results show that the obstacle affects the unburned flow field and generates compression waves and shear layers. The explosion promotion degree of the two obstacles presents different trends, and the peak pressure decreases. At the same time, obstacles reflect pressure waves, causing instability in the front of the flame. With the increase of plugging rate, the difference of peak pressure rises to 30% at BR = 0.4. The flame velocity of flexible obstacles is also more flat, and the peak velocity at BR = 0.2 and BR = 0.4 is close to 43 m/s. During the study, it was found that the flexible material can effectively absorb the reflected wave, and the pressure oscillation is absorbed. The average amplitude of the rigid oscillation rises from 4 kPa to 10 kPa, and the flexible oscillation decreases to nearly zero. The difference of barrier materials makes the impact of shock wave on flame and primary explosive injury (PBI) lighter, which is more conducive to assessing the explosion risk of combustible gas.

Comparison of Ultrasound Guided with Conventional Landmark Technique Caudal Block in Pediatric Patients Scheduled for Lower Abdomen Surgery under General Anesthesia: A Prospective Randomized Study

Background: Perioperative pain in pediatric population is a special concern and Caudal block is easy to perform extensively safe if used in children, resulting in low pain scores and when combined with general anaesthesia, it reduces the requirement for volatile agents, opioids, improved postoperative analgesia, and earlier extubation. Ultrasound guided caudal block has reduced the complication rates such as inadvertent dural or vascular puncture. Aim of the study was to compare the success rate of ultrasound guided with conventional landmark technique caudal block in pediatric patients undergoing lower abdominal surgery under general anaesthesia.&#x0D; Methods: Hundred pediatric patients, ASA class I, age between 6 months to 7 years of either sex, posted for lower abdomen surgery under general anaesthesia were randomly divided in to two groups. In group C- The group with caudal block using conventional landmark technique was used and Group U- The group with caudal block using ultrasound technique was used. Primary objectives of the study to find out the success rate of block in both the groups.&#x0D; Results: The demographic data were comparable in group C and group U. Significant difference was seen in the distribution of successful block between group C and group U. (p value 0.008) block was successful in 96% of patients in group U which was significantly higher as compared to group C (76%). significant difference was seen in the distribution of number of attempts between group C and group U. (p value 0.001).&#x0D; Conclusion: We conclude that Caudal block by ultrasound technique increases the first puncture success rate, decreases the number of multiple needle puncture attempts and overall success rate when compared to the conventional landmark technique in pediatric patients undergoing lower abdomen surgery.

Preparation and characterization of waterborne polyurethane based coating resins including near infrared blocking compound

Near infrared (NIR) rays, which account for 53% of sunlight, act as the strongest heat rays at 800–1,200 nm. Due to this heating action, the temperature inside a building or vehicle rises, which increases the use of air conditioners, energy consumption, and carbon dioxide generation increase. In order to solve this problem, a NIR blocking compound was prepared and introduced into the waterborne polyurethane (WPU) coating resin to prepare a WPU based coating resins including NIR blocking compound. As a result, a new absorption peak appeared around 870–910 nm which is the NIR region and a NIR blocking rate of 58.3% was confirmed.

Fear of childbirth and use of labor analgesia: A nationwide register-based analysis in Finland.

To calculate the rates of labor analgesia among women with fear of childbirth (FOC) in multiparous and nulliparous women, because FOC might be associated with higher rates of labor analgesia. In this retrospective register-based cohort study, data from the National Medical Birth Register was used to evaluate the usage of labor analgesia in pregnancies with FOC, when compared with those without. The analgesia methods were stratified into neuraxial analgesia, pudendal, paracervical, nitrous oxide, other medical, other non-medical, and no analgesia. A total of 19 285 pregnancies with diagnosed maternal FOC were found during our study period. The control group consisted of 757 997 pregnancies without diagnosed maternal FOC. Nulliparous women with diagnosed FOC had a higher rate of epidural analgesia (70.2% vs 67.1%), spinal analgesia (12.3% vs 7.6%), and pudendal block (17.6% vs 9.6%). Multiparous women with FOC had a notably higher rate for epidural analgesia (47.0% vs 29.0%). The main finding in this study was that women with diagnosed FOC had a higher rate of labor analgesia. The results of this study can be used by midwives, obstetricians, and anesthesiologists to provide optimal pain relief for mothers with FOC.

Trans-Reflective Structural Color Filters Assisting Multifunctional-Integrated Semitransparent Photovoltaic Window.

Multifunction-integrated semitransparent organic photovoltaic cells (STOPVs), with high power generation, colorful transmittance/reflectance, excellent UV protection, and thermal insulation, are fully in line with the concept of architectural aesthetics and photoprotection characteristics for building-integrated photovoltaic-window. For the indelible rainbow color photovoltaic window, one crucial issue is to realize the integration of these photons- and photoelectric-related multifunction. Herein, dynamic transmissive and reflective structural color controllable filters, with asymmetrical metal-insulator-metal configurations (20nm-Ag-HATCN-30nm-Ag) through machine learning, were deliberately designed for colorful STOPV devices. This endows the resultant integrated devices with ∼5% enhanced power conversion efficiency than the bare-STOPVs, gifted UV (300-400nm) blocking rates as high as 93.5, 94.1, 90.2, and 94.5%, as well as a superior IR (700-1400nm) rejection approaching 100% for transparent purple-, blue-, green- and red-STOPV cells, respectively. Most importantly, benefiting from the photonic recycling effect beyond microcavity resonance wavelength, a reported quantum utilization efficiency as high as 80%, was first presented for the transparent-green-STOPVs with an ultra-narrow bandgap of 1.2eV. These asymmetrical Febry-Pérot transmissive and reflective structural color filters can also be extended to silicon- and perovskite-based optoelectric devices and make it possible to integrate additional target optical functions for multi-purpose optoelectric devices. This article is protected by copyright. All rights reserved.

Determination of Critical Point of Particle Migration Direction in a Confined Shear Flow of Giesekus Fluids

Migration of a particle in a confined shear flow of Giesekus fluids is investigated numerically with the method of direct forcing/fictitious domain. We focus on the migration direction for the particle with initial lateral position y0 and determination of critical point yc of a particle moving towards the center line or wall. The effect of viscosity ratio μr, shear-thinning parameter α, Weissenberg number Wi, and blocking rate β on the value yc is analyzed. The results showed that when μr ≤ 0.5, the particle will migrate towards the wall regardless of the value of y0. When μr &gt; 0.5, yc increases with increasing μr, and some particles will migrate towards the center line with the increase in μr. The particle is more likely to migrate towards the center line at small values of Wi and α but at large values of μr. The impact of Wi and β on the particle migration direction is more obvious. The particle will migrate towards the wall for β = 0.3 and is more likely to migrate towards the wall with increasing β. α and Wi have little influence on the pressure distribution in the case of the same β and μr. The particle near the wall will migrate faster because large positive pressure and negative pressure appear around the particle.

Rate of residual neuromuscular block using single-dose rocuronium in general anesthesia for ENT surgery: a retrospective cohort study

IntroductionNMB facilitates intubating conditions in general anesthesia. However, it is associated with significant residual postoperative paralysis and morbidity.ObjectiveTo investigate the rate of underdiagnosed residual NMB based on two TOFR criteria (< 0.91 and < 1.00).MethodsWe performed a retrospective study adhering to STROBE guidelines. We included patients undergoing ENT surgery using single-dose neuromuscular block for balanced general anesthesia from June to December 2018. We collected demographic and anthropometric data, ASA score, NMBA dose, TOFR recordings at 5, 30 and 60 min and end of the surgery, anesthesia and surgery time, and administration of reversal agent. Statistical analysis included descriptive and dispersion measures statistics, curve and cross tables for residual NMB on different TOFR criteria with sub-analysis for AR, RR, and OR in patients over 65 years old.ResultsWe included 57 patients, mean age 41; 43 females and 14 males. Mean anesthetic and surgical time were 139.4 and 116.1 min, respectively. All the patients received rocuronium under a mean ponderal single-dose of 0.48 mg/kg. Residual NMB rates were 29.9 and 49.1% for a TOFR < 0.91 and < 1.00, respectively. Older adults had an OR of 6.08 for residual NMB.ConclusionsThe rate of residual NMB was 29.9 to 49.1%, depending on the criteria used (TOFR < 0.91 and < 1.00, respectively). Patients above 65 years old had an increased risk of residual NMB (6.08 OR) and clinical symptoms related to residual NMB (11.75 OR). We recommend future research aiming to provide a specific surveillance protocol for patients above 65 years old, including shorter-action NMB, early reversal, and prolonged surveillance using the TOFR criteria of < 1.00 to identify patients at risk of residual NMB readily.

Terminal Access Method of Power Equipment Based on eSIM in WSN Environment

To ensure the integration of wireless sensor network and broadband wireless communication network, we establish a new generation of power IoTs information communication system for smart grid, and propose a distribution automation terminal solution based on eSIM card. An adaptive access algorithm based on multi logic eSIM priority, and a WSN based power acquisition system architecture, are also put forward. Then, according to the statistical analysis results of service arrival, the dialing and location information are integrated into one module. Through terminal classification and mobile modeling, a remote management mechanism based on EUICC is finally established. The system simulation test results show that the strategy adopted in this article can reduce the terminal access blocking rate in heterogeneous network environment, and the support of eSIM in WSN environment increases the integration of power equipment.

Preparation and Performance Evaluation of a Temperature and Salt Resistant Hydrophobic Associative Weak Polymer Gel System.

We targeted high-temperature and highly saline old oil fields, whose environmental conditions could be attributed to the significantly high heterogeneity cause by long-term water flooding. The Huabei Oilfield was chosen as the research object. We developed a hydrophobic functional monomer-polymer with temperature and salt resistance by introducing the temperature-resistant and salt-resistant monomer NVP and a hydrophobic functional monomer into the main chain for copolymerization. We used a crosslinking agent with phenolic resin to prepare a weak gel system that showed temperature and salt resistance and investigated its temperature and salt resistance, infective property, plugging performance, liquid flow ability, micropore throat migration, and plugging characteristics. The results obtained using the infrared spectroscopy technique revealed the successful preparation of the phenolic resin crosslinker. The weak gel exhibited good temperature and salt resistance when the polymer concentration was 2000 mg/L, the cohesion ratio was 1:1.5, the additive concentration was 2000 mg/L, the reservoir temperature was 120 °C, and the injected water salinity was 40,300.86 mg/L. The average viscosity retention rate of the 90-day weak gel reached more than 80% and its microstructure was examined. The coreflow experiment results revealed that the weak gel system was characterized by good infectivity. After plugging the weak gel, the effect on the direction of the liquid flow was evident and the flow rate of the low permeability layer increased to a maximum of 48.63% under conditions of varying permeability levels. A significant improvement in the water absorption profile was achieved. The plugging was carried out through a sand-filling pipe under varying permeability conditions and the pressure measuring points in the sand-filling pipe were sucessfully pressurized. The migration ability of the weak gel was good and the blocking rate was >85%.

Do NSAIDs used prior to standard inferior alveolar nerve blocks improve the analgesia of mandibular molars with irreversible pulpitis? An umbrella review.

The aim of the present umbrella review was to answer the following question: "Does the use of NSAIDs as premedication increase the efficacy of the standard inferior alveolar nerve block on teeth with symptomatic irreversible pulpitis?" Systematic reviews with and without meta-analyses that evaluated the influence of premedication on anesthetic efficacy of the inferior alveolar nerve in symptomatic irreversible pulpitis of mandibular molars were searched in six electronic databases (MEDLINE/PubMed, Scopus, Web of Science, Cochrane Library, EMBASE, and Grey Literature Reports), without the restriction of language or year of publication. A Measurement Tool to Assess systematic Reviews (AMSTAR 2) was used to evaluate the quality of the included studies. Twelve systematic reviews were included. Only one did not perform a meta-analysis. The AMSTAR 2 overall confidence ranged from very low to high. In general, the main findings of the systematic reviews were that non-steroidal anti-inflammatory drugs (e.g., ibuprofen, oxicam, diclofenac, association of ibuprofen with acetaminophen, and ketorolac) increased the success rate of the inferior alveolar nerve block. From the "very low" to "high"-quality evidence available, this umbrella review concluded that NSAIDs as premedication acts through cyclooxygenase pathways and block the synthesis of specific prostaglandins that complicate the mechanism of action of the anesthesia, improving its success rate. Non-steroidal anti-inflammatory drugs can increase the success rate of the anesthetic technique of inferior alveolar nerve block efficacy in situations of mandibular molars with symptomatic irreversible pulpitis.

A mobility aware handover scheme for 4G LTE system

Reduction in cell size in an ultra-dense network faces the challenge of increase in frequency of handovers and signaling overhead (mobility management) as well as inter-cell interference. Such frequent handovers leads to increased packet loss and blocking rate if the handover latency is very high, which have adverse effect on connectivity and performance. However, most existing schemes have the common characteristics of increasing spectral and energy efficiency due to increase in the number of micro cell on a network, thus decreases the general network performance. In this study, an improved scheme was developed for fixed mobility management pattern (FMP). A comparison module was established and an identifier algorithm that uses the user equipment international mobile equipment identity (IMEI) as a decisive component of its cell selection camping process was designed. Network simulator (NS-3) was used to study the impact of macro cell and inter site distance (ISD) on user throughput and battery life usage using mobility pattern of 3km/h, with A3 event based measurement for ISD 50, 150, 300, 500, and 1000 respectively. The performance evaluation metrics used are; reference signal received power (RSRP), flow monitor and handover time. The FMP results were compared with micro cell performance in an ultra-dense network. The RSRP result from FMP was higher than that of micro cell at ISD 50 and 150 respectively (-71.36, -73.97 and 83.77, 85.13). The handover time for FMP was higher than that of micro cell except for ISD 50 which was 50s and 51s respectively. The flow monitor of FMP showed a packet loss ratio of 0.0001 compare to 0.21 of micro cell. The battery life usage shows that FMP used 5943±8.7mw compare to micro cell which used 1680.2±15.7 mw. These results showed that FMP is efficient in managing the frequency of handover and battery life consumption for better connectivity and performance.

Theoretical and numerical simulation investigation of deep hole dispersed charge cut blasting

Drilling and blasting methods have been used as a common driving technique for shallow-hole driving and blasting in rock roadways. With the advent of digital electronic detonators and the need for increased production efficiency, the traditional blasting design is no longer suitable for deep hole blasting. In this paper, a disperse charge cut blasting method was proposed to address the issues of low excavation depth and high block rate in deep hole undercut blasting. First, a blasting model was used to illustrate the mechanism of the deep hole dispersive charge cut blasting process. Then, continuous charge and dispersed charge blasting models were developed using the smooth particle hydrodynamics-finite element method (SPH-FEM). The cutting parameters were determined theoretically, and the cutting efficiency was introduced to evaluate the cutting effect. The blasting effects of the two charging models were analyzed utilizing the evolution law of rock damage, the number of rock particles thrown, and the cutting efficiency. The results show that using a dispersed charge improves the cutting efficiency by about 20% and the rock breakage for the deep hole cut blasting compared to the traditional continuous charge. In addition, important parameters such as cutting hole spacing, cutting hole depth and upper charge proportion also have a significant impact on the cutting effect. Finally, the deep hole dispersed charge cut blasting technology is combined with the digital electronic detonator through the field engineering practice. It provides a reference for the subsequent deep hole cutting blasting and the use of electronic detonators in rock roadways.

Filtering objectionable information access based on click-through behaviours with deep learning methods

This study explores URL click-through behaviour to predict the category of users’ online information accesses and applies the results to progressively filter objectionable accesses during web surfing. Each clicked URL is represented by the embedding technique and fed into the Bidirectional Long Short-Term Memory neural network cascaded with a Conditional Random Field (BiLSTM-CRF) model to predict the category of a user’s access. Large-scale experiments on click-through data from nearly one million real users show that our proposed BiLSTM-CRF model achieves promising results. The proposed method outperforms related approaches by a high accuracy of 0.9492 (near 27% relative improvement) for context-aware category prediction and an F1-score of 0.8995 (about 29% relative improvement) for objectionable access identification. In addition, in real-time filtering simulations, our model gradually achieves a macro-averaging blocking rate of 0.9221, while maintaining a favourably low false-positive rate of 0.0041.

Outcomes of cavotricuspid isthmus-dependent flutter ablation: randomized study comparing single vs. multiple catheter procedures-the SIMPLE study.

Catheter ablation is recommended as first-line therapy for patients with symptomatic typical AFl. Although the conventional multi-catheter approach is the standard of care for cavotricuspid isthmus (CTI) ablation, a single-catheter approach was recently described as a feasible alternative. The present study sought to compare safety, efficacy, and efficiency of single vs. multi-catheter approach for atrial flutter (AFl) ablation. In this randomized multi-center study, consecutive patients referred for AFl ablation (n = 253) were enrolled and randomized to multiple vs. single-catheter approach for CTI ablation. In the single-catheter arm, PR interval (PRI) on the surface ECG was used to prove CTI block. Procedural and follow-up data were collected and compared between the two arms. 128 and 125 patients were assigned to the single-catheter and to the multi-catheter arms, respectively. In the single-catheter arm, procedure time was significantly shorter (37 ± 25 vs. 48 ± 27 minutes, p = 0.002) and required less fluoroscopy time (430 ± 461 vs. 712 ± 628 seconds, p < 0.001) and less radiofrequency time (428 ± 316 vs. 643 ± 519 seconds, p < 0.001), achieving a higher first-pass CTI block rate (55 (45%) vs. 37 (31%), p = 0.044), compared with the multi-catheter arm. After a median follow-up of 12 months, 11 (4%) patients experienced AFl recurrences (5 (4%) in the single-catheter arm and 6 (5%) in the multi-catheter arm, p = 0.99). No differences were found in arrhythmia-free survival between arms (log-rank = 0.71). The single-catheter approach for typical AFl ablation is not inferior to the conventional multiple-catheter approach, reducing procedure, fluoroscopy, and radiofrequency time.