scholarly journals Image-based modeling and characterization of RF ablation lesions in cardiac arrhythmia therapy

2013 ◽  
Author(s):  
Cristian A. Linte ◽  
Jon J. Camp ◽  
Maryam E. Rettmann ◽  
David R. Holmes ◽  
Richard A. Robb
Keyword(s):  
Cardiac Arrhythmia ◽  
Rf Ablation ◽  
Image Based Modeling ◽  
Arrhythmia Therapy ◽  
Cardiac Arrhythmia Therapy

scholarly journals Transesophageal 2D ultrasound to 3D computed tomography registration for the guidance of a cardiac arrhythmia therapy

2018 ◽  
Vol 63 (15) ◽  
pp. 155007 ◽  
Author(s):  
Zulma Sandoval ◽  
Miguel Castro ◽  
Javad Alirezaie ◽  
Francis Bessière ◽  
Cyril Lafon ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cardiac Arrhythmia ◽  
3D Computed Tomography ◽  
2D Ultrasound ◽  
Arrhythmia Therapy ◽  
Cardiac Arrhythmia Therapy

scholarly journals Characteristics of pulmonary vein gaps through a novel local impedance algorithm at repeat AF ablation procedures: preliminary results from the CHARISMA registry

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
L Segreti ◽  
R Maggio ◽  
G Izzo ◽  
G Bencardino ◽  
G Zucchelli ◽  
...  
Keyword(s):  
Pulmonary Vein ◽  
Scar Tissue ◽  
Complete Characterization ◽  
Healthy Tissue ◽  
Rf Ablation ◽  
Af Ablation ◽  
Funding Sources ◽  
The Difference ◽  
Procedural Success

Abstract Funding Acknowledgements Type of funding sources: None. Background A high incidence of pulmonary vein (PV) reconnection has been reported in patients with clinical recurrences of AF. Detailed characterization of PV gaps in terms of local impedance (LI) is still lacking. Purpose to characterize PV gaps with a novel local impedance algorithm during redo PV ablation in AF patients (pts). Methods Consecutive pts undergoing repeated AF ablation from the CHARISMA registry with complete characterization of PV gaps through local impedance at 6 Italian centers were included. A complete map of the left atrium and PVs was performed prior and after ablation through the Rhythmia mapping system. A novel RF ablation catheter with dedicated algorithm (DirectSense) was used to measure LI at the distal electrode of this catheter. Each gap was characterized in terms of LI and its variations during ablation procedure according to different ablation sites around the PVs. 7 sites around the left and right pair of PV for LI evaluation during ablation were defined: 2 for posterior sites (PS) (posterior inferior and posterior superior), 2 for anterior sites (AN) (anterior inferior and anterior superior), 1 for interior site (INF), 1 for superior site (SUP) and 1 for the carina (CAR). Ablation endpoint was PVI as assessed by entrance and exit block. Results Eighteen cases of redo AF ablation were analyzed (9 after prior RF ablation, 9 after prior cryoablation). A total of 41 PV gaps were detected (20 after RF ablation, 21 after cryoablation; mean number of gaps per pt = 2.3 ± 1.1): one gap was identified In five (27.8%) pts, 2 gaps were present in 7 (38.9%) pts, 3 gaps were detected in 2 (11.1%) pts and 4 gaps were identified in the remaining 4 (22.2%) pts. PV gaps were most common at AN sites (17, 41.5%), followed by PS sites (12, 29.3%) and CAR sites (11, 28.6%). The mean LI at gap sites was 113.9 ± 15Ω prior to ablation: it was significantly higher than LI at scar tissue closer to gap (99.7 ± 8Ω, p < 0.0001) but was significantly lower than LI at healthy tissue (120.2 ± 12Ω, p < 0.0001). LI parameters did not differ between prior ablation approach (RF vs Cryo: 115.5 ± 13Ω vs 112.2 ± 16Ω for LI at gap, p = 0.4739; 102.2 ± 6Ω vs 97.3 ± 10Ω LI at scar tissue, p = 0.0591; 16.4 ± 4Ω vs 15.8 ± 13Ω for LI drop at gap, p = 0.6647). In 14 cases (34.1%) the difference between LI at healthy tissue and LI at gap was lower than 5Ω, suggesting that this spot was not treated by RF or Cryo delivery in the previous ablation session (13 out 21 after Cryo ablation vs 1 out 20 after RF ablation, p < 0.0001). No complications during the procedures were reported. The acute procedural success was 100%, with all PVs successfully isolated in all study patients. Conclusion In our preliminary experience, PV gaps after failed PVI were most common at anterior, followed by posterior and carina sites. LI characteristics at PV gaps significantly differ from both scar and healthy tissue and could be used to target ablation deliveries.

scholarly journals Image-based metric heritage modeling in the near-infrared spectrum

2020 ◽  
Author(s):  
Efstathios Adamopoulos ◽  
Alessandro Bovero ◽  
Fulvio Rinaudo
Keyword(s):  
Near Infrared ◽  
Three Dimensional ◽  
Visible Spectrum ◽  
Lighting Conditions ◽  
Image Based Modeling ◽  
Spectral Models ◽  
Software Implementations ◽  
Automatic Software ◽  
Accuracy Of Results

Abstract Digital photogrammetry and spectral imaging are widely used in heritage sciences, towards the comprehensive recording, understanding, and protection of historical artefacts and artworks. The availability of consumer-grade modified cameras for spectral acquisition, as an alternative to expensive multispectral sensors and multi-sensor apparatuses, along with semi-automatic software implementations of Structure-from-Motion (SfM) and Multiple-View-Stereo (MVS) algorithms, has made more feasible than ever the combination of those techniques. In the research presented here, the authors assess image-based modeling from near-infrared (NIR) imagery acquired with modified sensors, with applications on tangible heritage. Three-dimensional meshes, textured with the non-visible data, are produced and evaluated. Specifically, metric evaluations are conducted through extensive comparisons with models produced with high-resolution visible (VIS) spectrum image-based modeling, to check accuracy of results. Furthermore, the authors observe and discuss, when the implemented NIR modeling approach, enhances the preservation of surface detail on the reconstructed spectral models or counteracts certain problems arising from lighting conditions during VIS acquisition. Radiometric properties of the produced results are evaluated on the capacity to enhance observation towards the characterization of surface and under-surface state of preservation, and consequently, to support conservation interventions, in comparison to the respective results in visible spectrum.

P565First characterization of high-power short-duration radiofrequency ablation with remote magnetic navigation assistance

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
G Caluori ◽  
E Odehnalova ◽  
J Krenek ◽  
T Jadczyk ◽  
M Pesl ◽  
...  
Keyword(s):  
Short Duration ◽  
High Power ◽  
Calibration Curve ◽  
Left Ventricular ◽  
Right Atrial ◽  
Pathological Examination ◽  
Magnetic Navigation ◽  
Rf Ablation ◽  
Remote Magnetic Navigation

Abstract Funding Acknowledgements MEYS- CR (ref#LQ1605 and LM2015062) Background/Introduction High-power short-duration (HPSD) radiofrequency (RF) ablation relies on the application of intense thermal fields for a carefully restricted time, in order to quickly obtain deep but precise lesions that spare the structures surrounding the heart. The approach is still under evaluation across different therapies and catheter technologies. To the present day there is no available characterization of HPSD ablation supported by remote magnetic navigation (RMN). Purpose To describe the safety issues regarding HPSD ablation in atria and ventricles with RMN systems, while characterizing the thermal lesion size and continuity in an acute closed-chest swine model. Methods The animal trial was divided in two arms (left ventricular and atrial). 10 female large white pigs (6-month-old weight 55-65 kg) were employed in each arm. Endocardial electroanatomical mapping and ablation were performed with RMN assistance to provide stable contact and flexible maneuvering. The ventricular cohort was divided in 5 power settings (30-40-50-60-70W). Multiple RF applications (10 ca./animal) were delivered until a pop occurred or up to 60s. In the atrial cohort the animals were divided by a combination of power/application time (50W/20s – 70W/10s – 90W/4s). Intracaval right atrial ablation lines and postero-lateral left atrial lines were performed in a point-by-point fashion (ca. 4mm distance). Irrigation rate was 30ml/min. The ventricular lesions were measured via software after 9.4T MRI of fixed hearts. The atrial lesions were measures during pathological examination after explanation. Results In the ventricular arm, we obtained a safety calibration curve linking the imposed power setting to the maximal time of application. The time before a pop decreased non-linearly from 60s down to 17.69 ± 8.21 s at 70W. No statistically significant differences were observed when comparing lesions depth, width and volume among the selected power settings. In the atrial arm we observed on the post-ablation maps a significant decrease of intracaval lesions (i.e. area with bipolar voltage <1.5mV) width (17.57 ± 1.89 mm for 50W/4s down to 10.16 ± 1.56 mm for 90W/4s). Pericardial, pleural and aortic damages were visible across all the employed settings, with less pronounced alterations for 90W/4s. Transmural lesions were visible both on the right and left atrium, with evident gaps for 50W/20s. Conclusion The presented work assesses for the first time the safety limits of HPSD ablation on healthy ventricular myocardium. We provide a calibration curve for faster RF ablation with comparable lesion features. Furthermore, we expanded the previously reported application in the atrium adding the benefits of stable controlled contact provided by RMN systems. We highlighted the benefits (e.g. faster, continuous and localized lesion formation) and risks for peripheral structures using HPSD ablation for supraventricular tachycardia interventions. Abstract Figure.

Characterization of ECG beats from cardiac arrhythmia using discrete cosine transform in PCA framework

2013 ◽  
Vol 45 ◽  
pp. 76-82 ◽  
Author(s):  
Roshan Joy Martis ◽  
U. Rajendra Acharya ◽  
Choo Min Lim ◽  
Jasjit S. Suri
Keyword(s):  
Discrete Cosine Transform ◽  
Cardiac Arrhythmia ◽  
Cosine Transform

A Multi-Zone Finite Element Model for Radiofrequency Ablation of an Infarcted Cardiac Tissue

2007 ◽  
Author(s):  
Fan Zhou ◽  
Ying Sun ◽  
Jacques Beaumont
Keyword(s):  
Finite Element ◽  
Cardiac Arrhythmia ◽  
Element Model ◽  
Severe Bleeding ◽  
Minimal Amount ◽  
Fe Model ◽  
Rf Ablation ◽  
Imaging Data ◽  
Conduction Model ◽  
Thermo Electric

A large number of modern day medical interventions rely on RF ablation. It has become the treatment of choice for many types of cardiac arrhythmia to prevent the reentrant circuits [1]. However, excessive heating during RF ablation up to 100°C can cause microexplosions and severe bleeding [2]. Optimizing parameters for RF ablation in order to produce small lesions with a minimal amount of damage and bleeding constitutes a major challenge. Utilizing a thermo-electric conduction model, we address this problem for the treatment of cardiac arrhythmia. Our objective is to provide means by which non-invasive cardiac imaging data can be used to determine optimal parameters of RF ablation. A three-dimensional (3-D) finite element (FE) model that includes healthy, infarcted, and slow conducting tissues is developed. The temperature dependent thermal and electrical conductivities are considered for different tissue types.

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