P1379Fluoroscopy requirement reduction using an esophageal cooling protocol during left atrial ablation

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
J Zagrodzky ◽  
S Bailey ◽  
S Shah ◽  
E Kulstad
Keyword(s):  
Fluoroscopy Time ◽  
Esophageal Injury ◽  
Rf Ablation ◽  
Cooling Device ◽  
Atrial Ablation ◽  
Single Sensor ◽  
The Difference ◽  
Sensor Temperature ◽  
Time Required ◽  
Cold Liquid

Abstract Background Ablation of the left atrium with radiofrequency (RF) energy is associated with some risks to the esophagus.  Cooling the esophagus has been used as one approach to reducing esophageal injury, most commonly with direct instillation of cold liquid via gastric tube placed in the esophagus.  A new esophageal cooling device avoids the risks of free liquid instillation by using a closed-loop system, and avoids the need for frequent repositioning or stopping of the procedure often required when utilizing luminal esophageal temperature (LET) monitoring.  This in turn may reduce fluoroscopy requirements for the procedure. Purpose Measure the difference in fluoroscopy time required during RF ablation using an esophageal cooling device protocol, and compare this to standard LET monitoring using single or multi-sensor temperature probes. Methods We obtained total fluoroscopy time per patient from records of RF ablation procedures performed by a two operators over a 12 month period.  We compared fluoroscopy times between patients treated with an esophageal cooling device to control patients who were treated with LET monitoring using either single-sensor or multi-sensor temperature probes. Results Fluoroscopy times were available for a total of 179 patients treated with an esophageal cooling device, and 118 patients treated with LET monitoring over the 12 month study period.  Mean fluoroscopy time for patients treated with esophageal cooling was 4.0 minutes (SD 4.9 minutes) with a median of 2.0 minutes (IQR 1.3 to 3.8 minutes).  Mean fluoroscopy time for patients undergoing LET monitoring was 5.5 minutes (SD 5.7 minutes) with a median of 3.0 minutes (IQR 1.9 to 8.4 minutes).  This difference represents a 27% reduction in mean fluoroscopy time, and a 33% reduction in median fluoroscopy time in the esophageal cooling group (p<.001, Mann-Whitney U test). Conclusions  Fluoroscopy requirements were reduced by 27% with an esophageal cooling device when compared to standard LET monitoring.

P1861Influence of thermal conductivity on esophageal protection with a cooling device during high-power short-duration radiofrequency ablation

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
E Kulstad ◽  
M Mercado-Montoya ◽  
S Shah
Keyword(s):  
Thermal Conductivity ◽  
Short Duration ◽  
High Power ◽  
Operating Conditions ◽  
Whole Body ◽  
Esophageal Injury ◽  
Cooling Power ◽  
Protective Effects ◽  
Rf Ablation ◽  
Cooling Device

Abstract Introduction Recent clinical data show that high-power, short-duration (HPSD) radiofrequency (RF) ablation can result in a similar esophageal injury rate as traditional low-power, long-duration (LPLD) ablation. Existing methods to prevent esophageal injury have yielded mixed results and can result in prolonged procedure time, potentially increasing the incidence of post-operative cognitive dysfunction. A new esophageal cooling device currently available for whole-body temperature modulation is being studied for the prevention of esophageal injury during LPLD RF ablation and cryoablation. We sought to develop a mathematical model of HPSD ablation in order to quantify the capability of this new esophageal cooling device to protect from esophageal injury under high-power conditions. Methods Using a model we developed of HPSD RF ablation in the left atrium, we measured the change in esophageal lesion formation and the depth of lesions (measured as percent transmurality) with the esophageal cooling device in place and operating at a temperature from 5°C to 37°C. Tissue parameters, including thermal conductivity, were set to average values obtained from existing literature, and energy settings were evaluated at 50W for between 5 and 10 seconds, and at 90W for a duration of 4 seconds. Results Esophageal injury as measured by percent transmurality was considerably higher at 50W and 10s duration than at 90W of power with 4s duration, although both settings showed potential for esophageal injury. The protective effect of the esophageal cooling device was evident for both cases, with a greater effect when using 50W for 10s (Figure 1). At the coldest device settings, using a 5 min pre-cooling period also reduced the transmurality of the intended atrial lesions. Esophageal protection in HPSD ablation Conclusions Esophageal cooling with a new patient temperature management device shows protective effects against thermal injury during RF ablation across a range of tissue thermal conductivity, using a variety of high-power settings, including 90W applied for 4 seconds. Adjusting the cooling power by adjusting the circulating water temperature in the device allows for a tailoring of the protective effects to operating conditions. Acknowledgement/Funding Attune Medical

scholarly journals Esophageal cooling for protection during left atrial ablation: a systematic review and meta-analysis

2019 ◽  
Vol 59 (2) ◽  
pp. 347-355 ◽  
Author(s):  
Lisa WM Leung ◽  
Mark M Gallagher ◽  
Pasquale Santangeli ◽  
Cory Tschabrunn ◽  
Jose M Guerra ◽  
...  
Keyword(s):  
Thermal Injury ◽  
Cold Water ◽  
Meta Analysis ◽  
Extraction Methods ◽  
Heat Extraction ◽  
Esophageal Injury ◽  
Rf Ablation ◽  
Extraction Capacity ◽  
Model Studies ◽  
Atrial Ablation

Abstract Purpose Thermal damage to the esophagus is a risk from radiofrequency (RF) ablation of the left atrium for the treatment of atrial fibrillation (AF). The most extreme type of thermal injury results in atrio-esophageal fistula (AEF) and a correspondingly high mortality rate. Various strategies for reducing esophageal injury have been developed, including power reduction, esophageal deviation, and esophageal cooling. One method of esophageal cooling involves the direct instillation of cold water or saline into the esophagus during RF ablation. Although this method provides limited heat-extraction capacity, studies of it have suggested potential benefit. We sought to perform a meta-analysis of published studies evaluating the use of esophageal cooling via direct liquid instillation for the reduction of thermal injury during RF ablation. Methods We searched PubMed for studies that used esophageal cooling to protect the esophagus from thermal injury during RF ablation. We then performed a meta-analysis using a random effects model to calculate estimated effect size with 95% confidence intervals, with an outcome of esophageal lesions stratified by severity, as determined by post-procedure endoscopy. Results A total of 9 studies were identified and reviewed. After excluding preclinical and mathematical model studies, 3 were included in the meta-analysis, totaling 494 patients. Esophageal cooling showed a tendency to shift lesion severity downward, such that total lesions did not show a statistically significant change (OR 0.6, 95% CI 0.15 to 2.38). For high-grade lesions, a significant OR of 0.39 (95% CI 0.17 to 0.89) in favor of esophageal cooling was found, suggesting that esophageal cooling, even with a low-capacity thermal extraction technique, reduces the severity of lesions resulting from RF ablation. Conclusions Esophageal cooling reduces the severity of the lesions that may result from RF ablation, even when relatively low heat extraction methods are used, such as the direct instillation of small volumes of cold liquid. Further investigation of this approach is warranted, particularly with higher heat extraction capacity techniques.

scholarly journals Esophageal Cooling For Protection During Left Atrial Ablation: A Systematic Review And Meta- Analysis

2019 ◽  
Author(s):  
Lisa Leung ◽  
Mark Gallagher ◽  
Pasquale Santangeli ◽  
Cory Tschabrunn ◽  
Jose Guerra ◽  
...  
Keyword(s):  
Thermal Injury ◽  
Cold Water ◽  
Meta Analysis ◽  
Extraction Methods ◽  
Heat Extraction ◽  
Esophageal Injury ◽  
Rf Ablation ◽  
Model Studies ◽  
Atrial Ablation ◽  
Lesion Severity

ABSTRACTBackgroundThermal damage to the esophagus is a risk from radiofrequency (RF) ablation of the left atrium for the treatment of atrial fibrillation (AF), with the most extreme type of thermal injury resulting in atrio-esophageal fistula (AEF), with a correspondingly high mortality rate. Various approaches have been developed to reduce esophageal injury, including power reduction, avoidance of greater contact-force, esophageal deviation, and esophageal cooling. One method of esophageal cooling involves direct instillation of cold water or saline into the esophagus during RF ablation. Although this method provides limited heat-extraction capacity, studies of it have suggested potential benefit.ObjectiveWe sought to perform a meta-analysis of existing studies evaluating esophageal cooling via direct liquid instillation for the reduction of thermal injury.MethodsWe reviewed Medline for existing studies involving esophageal cooling for protection of thermal injury during RF ablation. A meta-analysis was then performed using random effects model to calculate estimated effect size with 95% confidence intervals, with outcome of esophageal lesions, stratified by severity, as determined by post-procedure endoscopy.ResultsA total of 9 studies were identified and reviewed. After excluding pre-clinical and mathematical model studies, 3 were included in the meta-analysis, totaling 494 patients. Esophageal cooling showed a tendency to shift lesion severity downward, such that total lesions did not show a statistically significant change (OR 0.6, 95% CI 0.15 to 2.38). For high grade lesions, a significant OR of 0.39 (95% CI 0.17 to 0.89) in favor of esophageal cooling was found, suggesting that esophageal cooling, even utilizing a low-capacity thermal extraction technique, reduces lesion severity from RF ablation.ConclusionsEsophageal cooling reduces lesion severity encountered during RF ablation, even when using relatively low heat extraction methods such as direct instillation of cold liquid. Further investigation of this approach is warranted.

scholarly journals A Fast Retrieval of Cloud Parameters Using a Triplet of Wavelengths of Oxygen Dimer Band around 477 nm

2021 ◽  
Vol 13 (1) ◽  
pp. 152
Author(s):  
Haklim Choi ◽  
Xiong Liu ◽  
Gonzalo Gonzalez Abad ◽  
Jongjin Seo ◽  
Kwang-Mog Lee ◽  
...  
Keyword(s):  
Scattered Light ◽  
Trace Gas ◽  
Retrieval Algorithm ◽  
The Novel ◽  
Cloud Parameters ◽  
Retrieval Scheme ◽  
The Difference ◽  
The Look ◽  
Time Required ◽  
Cloud Top Pressure

Clouds act as a major reflector that changes the amount of sunlight reflected to space. Change in radiance intensity due to the presence of clouds interrupts the retrieval of trace gas or aerosol properties from satellite data. In this paper, we developed a fast and robust algorithm, named the fast cloud retrieval algorithm, using a triplet of wavelengths (469, 477, and 485 nm) of the O2–O2 absorption band around 477 nm (CLDTO4) to derive the cloud information such as cloud top pressure (CTP) and cloud fraction (CF) for the Geostationary Environment Monitoring Spectrometer (GEMS). The novel algorithm is based on the fact that the difference in the optical path through which light passes with regard to the altitude of clouds causes a change in radiance due to the absorption of O2–O2 at the three selected wavelengths. To reduce the time required for algorithm calculations, the look-up table (LUT) method was applied. The LUT was pre-constructed for various conditions of geometry using Vectorized Linearized Discrete Ordinate Radiative Transfer (VLIDORT) to consider the polarization of the scattered light. The GEMS was launched in February 2020, but the observed data of GEMS have not yet been widely released. To evaluate the performance of the algorithm, the retrieved CTP and CF using observational data from the Global Ozone Monitoring Experiment-2 (GOME-2), which cover the spectral range of GEMS, were compared with the results of the Fast Retrieval Scheme for Clouds from the Oxygen A band (FRESCO) algorithm, which is based on the O2 A-band. There was good agreement between the results, despite small discrepancies for low clouds.

scholarly journals Events, Time and the Simple Form

2009 ◽  
Vol 17 (1) ◽  
pp. 85-105 ◽  
Author(s):  
Walter H. Hirtle
Keyword(s):  
Simple Form ◽  
Point Of View ◽  
Event Time ◽  
The Difference ◽  
Time Required ◽  
English Verb

Abstract This is an attempt to discern more clearly the underlying or POTENTIAL meaning of the simple form of the English verb, described in Hirtle 1967 as 'perfective'. Vendler's widely accepted classification of events into ACCOMPLISHMENTS, ACHIEVEMENTS, ACTIVITIES, and STATES is examined from the point of view of the time necessarily contained between the beginning and end of any event, i.e. EVENT TIME as represented by the simple form. This examination justifies the well known dynamic/stative dichotomy by showing that event time is evoked in two different ways, that, in fact, the simple form has two ACTUAL significates. Further reflection on the difference between the two types thus expressed—developmental or action-like events and non-developmental or state-like events—leads to the conclusion that the simple form provides a representation of the time required to situate all the impressions involved in the notional or lexical import of the verb.

scholarly journals Pembuatan dan Pengujian Mesin Pemotong Lidi Tusuk Sate

2019 ◽  
Vol 4 (4) ◽  
pp. 421-430
Author(s):  
Gusri Akhyar Ibrahim ◽  
Arinal Hamni ◽  
Wahyu Budiono
Keyword(s):  
Cutting Machine ◽  
Simple Tool ◽  
Business Opportunities ◽  
The Difference ◽  
Time Required ◽  
At Home

MAKING AND TESTING OF SKEWERS CUTTING MACHINES. In Indonesia there are more than 100 types of bamboo that can be used by craftsmen, one of which is skewers. Skewers are promising commodities for business opportunities. The process of producing skewers are started from cutting down the bamboo, cutting bamboo, splitting bamboo, shriveling bamboo to become a stick skewer after that is done cutting the skewer sticks, drying sticks, polishing the sticks skewers and chopping sticks. The process of cutting a stick skewer which is done at this time is still using a simple tool, so the results are bad and the cutting time is very long. To maintain the quality of the results of a good stick skewer sticks and to increase the productivity of the stick skewers, the process of producing and testing of a skewer stick cutting machine is done. The method to produce a skewer stick cutting machine is done by designing the tool, determining the material to be used then making it. This skewer stick cutting machine is made with a press system and vertical cutting directions. From the results of testing the skewer stick cutting machine obtained that the quality of skewer cutting is good and the time required to cut is only 10 seconds. the difference is about 50 seconds faster than the hand saws used, so as to increase the productivity of the skewer sticks. The cutting machine was impelemented at home industry at Sidomulyo of South Lampung. Using the machine has increased productity and also quality of skewers.

Individual vs Group Learning: Note on Two Task Variables

1968 ◽  
Vol 23 (3) ◽  
pp. 757-758 ◽  
Author(s):  
Herman S. Napier
Keyword(s):  
Present Experiment ◽  
Group Formation ◽  
Group Learning ◽  
Nominal Groups ◽  
Group Members ◽  
Task Variables ◽  
The Difference ◽  
Time Required ◽  
Puzzle Task

The pooling of abilities or nominal groups technique was used in the present experiment to compare individuals with two-person groups on a picture-puzzle task. When size of the task was limited to a part (one-fourth) of the puzzle or the duration of the task was restricted to a few (four) trials, no difference between individuals and groups was evident. However, as task size and number of trials increased, groups performed at a significantly higher level than individuals. The difference was discussed in terms of information available to group members and the time required for group formation.

Moving away from esophageal injury during left atrial ablation

Heart Rhythm ◽  
2009 ◽  
Vol 6 (3) ◽  
pp. 323-324 ◽  
Author(s):  
T. Jared Bunch ◽  
John D. Day
Keyword(s):  
Left Atrial ◽  
Esophageal Injury ◽  
Atrial Ablation

Cardiorespiratory responses of sedentary college women as a function of training intensity

1976 ◽  
Vol 41 (6) ◽  
pp. 822-825 ◽  
Author(s):  
J. T. Kearney ◽  
G. A. Stull ◽  
J. L. Ewing ◽  
J. W. Strein
Keyword(s):  
Heart Rate ◽  
College Women ◽  
Experimental Period ◽  
Exercise Heart Rate ◽  
Training Intensity ◽  
Treadmill Speed ◽  
Training Response ◽  
O2 Pulse ◽  
The Difference ◽  
Time Required

Twenty-seven sedentary college women trained on a treadmill 3 times weekly over a 9-wk experimental period. Subjects exercised at a heart rate (HR)of either 50 or 65% of the HR reserve added to the resting HR with the duration of each session limited to the time required to elicit 1,000 beats above the resting value. Treadmill speed was adjusted automatically to maintain the prescribed exercise heart rate (EHR) within +/- 5 beats-min(-1). A comparison of the pretraining and posttraining results revealed that both training intensities caused significant increases in VO2max (1-min(-1) and ml-kg(-1)-min(-1)), V at VO2max, and O2 pulse at VO2max, and a significant decrease in VEO2 at VO2max. There was no alteration in EHR at VO2max for either intensity. For every dependent variable in which training effects were noted, the absolute gain made by the subjects training at the 65% intensity was greater than for those exercising at 50%. In no instance, however, was the difference between groups statistically significant. It was concluded that training at an EHR of either 50 or 65% of the HR reserve plus resting HR is sufficient to elicit a training response.

scholarly journals 3D Rigid Registration of Intraoperative Ultrasound and Preoperative MR Brain Images Based on Hyperechogenic Structures

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Pierrick Coupé ◽  
Pierre Hellier ◽  
Xavier Morandi ◽  
Christian Barillot
Keyword(s):  
Intraoperative Ultrasound ◽  
Joint Probability ◽  
Computation Time ◽  
Visual Assessment ◽  
Neurosurgical Procedures ◽  
Registration Accuracy ◽  
Brain Images ◽  
Study Results ◽  
The Difference ◽  
Time Required

The registration of intraoperative ultrasound (US) images with preoperative magnetic resonance (MR) images is a challenging problem due to the difference of information contained in each image modality. To overcome this difficulty, we introduce a new probabilistic function based on the matching of cerebral hyperechogenic structures. In brain imaging, these structures are the liquid interfaces such as the cerebral falx and the sulci, and the lesions when the corresponding tissue is hyperechogenic. The registration procedure is achieved by maximizing the joint probability for a voxel to be included in hyperechogenic structures in both modalities. Experiments were carried out on real datasets acquired during neurosurgical procedures. The proposed validation framework is based on (i) visual assessment, (ii) manual expert estimations , and (iii) a robustness study. Results show that the proposed method (i) is visually efficient, (ii) produces no statistically different registration accuracy compared to manual-based expert registration, and (iii) converges robustly. Finally, the computation time required by our method is compatible with intraoperative use.

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