scholarly journals Assessment of local high-density mapping for the analysis of radiofrequency ablation lesions in the left atrium

2017 ◽  
Vol 3 (2) ◽  
pp. 109-112
Author(s):  
Michael Stritt ◽  
Tobias Oesterlein ◽  
Stefan Pollnow ◽  
Armin Luik ◽  
Claus Schmitt ◽  
...  
Keyword(s):  
Time Delay ◽  
Low Voltage ◽  
Relevant Information ◽  
Lesion Size ◽  
High Density ◽  
Rf Ablation ◽  
Activation Time ◽  
Peak Voltage ◽  
Density Mapping ◽  
The Mean

AbstractRecent studies about the development of endocardial radiofrequency (RF) ablation lesions (ALs) tried to identify reliable electrogram (EGM) markers for assessment of lesion transmurality. Additional clinically relevant information for physicians can be provided by examining endocardial EGM parameters like signal morphology, amplitude or time points in the signal. We investigated EGM features of the pulmonary vein ostia before and after RF ablation for three point-shaped lesions. Using high-density (HD) mapping, local activation time (LAT) and voltage maps were created, which provided information about the RF ALs regarding the lesion size and showed activation time delay as well as low-voltage areas with bipolar peak-to-peak voltages smaller than 2mV. The time delay of the depolarization front comparing the activation times anterior and posterior to the RF AL was up to 51.5 ms. In a circular area with 5mm radius around an RF AL the mean peak-to-peak voltage decreased by 62-94% to about 0.12-0.44mV and the mean maximal absolute EGM derivative was reduced by 65-96 %. Comparing the results of this study with EGMs of similar clinical settings confirmed our expectations regarding the low-voltage areas caused by the ablation procedure. An improved understanding of the electrophysiological changes is of fundamental importance to provide more information for enhanced RF ablation assessment.

scholarly journals Distribution and area of low voltage and dense scar zones and their relation to left atrial enlargement in ablation-naïve patients with paroxysmal atrial fibrillation

2020 ◽  
Vol 26 (3) ◽  
pp. 52-64
Author(s):  
Tchavdar Shalganov ◽  
Milko Stoyanov ◽  
Metodi Mirazchiyski ◽  
Boyan Kunev
Keyword(s):  
Left Atrial ◽  
Low Voltage ◽  
Measured Data ◽  
High Density ◽  
P Value ◽  
Moderate Correlation ◽  
Anova Analysis ◽  
Density Mapping ◽  
Atrial Enlargement ◽  
The Mean

There is paucity of studies correlating the left atrial (LA) dilation and the LA total and abnormal voltage areas in patients with atrial fi brillation (AF). We sought to determine the area of LA and its segments by high-density mapping in patients with paroxysmal AF, and to correlate the LA dilation defi ned by echocardiography with the total and the abnormal LA areas. Material and Methods. Retrospective study of patients with paroxysmal AF and pulmonary vein isolation proceeded by high-density mapping in sinus rhythm. All had transthoracic echocardiography and LA dilation, if present, was graded as mild/moderate-severe. LA voltage was defi ned as low (< 0.5 mV) or scar (< 0.1 mV). The LA was divided in 5 segments and the total and segmental area, low voltage area and scar area were measured. Data were presented as mean ± SD or median and interquartile interval (25-75%) depending on normality of distribution. Shapiro-Wilk test, Spearman T correlation, Kruskal-Wallis, and ANOVA analysis were used. A p-value < 0.05 was considered significant. Results.  Sixty-seven patients (66% males) were studied. LA enlargement was present in 58% (mild enlargement in 39%, moderate/severe in 19%). Low voltage and scar areas were found in both groups with and without LA dilation. Moderate correlation was found between the percentage of abnormal area and the degree of LA dilation (none vs mild vs moderate/severe), rho = 0.44, p = 0.0002. In patients with non-dilated LA the mean total LA area was 100.4 ± 17 cm2 and the abnormal area was < 10% (9.9%, 6.2-14.8%), with barely detectable scar. In patients with LA enlargement the total area was approximately 10% larger (109.8 cm2, 100.9-123.8 cm2), however the abnormal area was almost doubled (17.1%, 11.1-26.8%), and there were small yet measurable dense scar areas. Conclusions. Low voltage LA areas < 0.5 mV were found universally by high-density mapping in patients with paroxysmal AF, irrespective of the presence of LA enlargement. However, only patients with LA enlargement had measurable scar areas. The total abnormal area correlated moderately with the degree of LA dilation defi ned by echocardiography.

Simultaneous orthogonal bipole mapping compared to conventional electrode configurations and impact on ablation strategies: results from a real world observational study

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
L Fiedler ◽  
F Roithinger ◽  
I Roca ◽  
F Lorgat ◽  
A Roux ◽  
...  
Keyword(s):  
Catheter Ablation ◽  
Observational Study ◽  
Real World ◽  
Low Voltage ◽  
High Density ◽  
Electrode Configuration ◽  
Density Mapping ◽  
Substrate Identification ◽  
Myocardial Substrate ◽  
Vt Ablation

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Abbott Background 3D mapping systems are pivotal to identify low voltage areas and to define ablation strategies. In this context, high-density multipolar mapping catheters with varying electrode configurations are used for accurate myocardial substrate definition. High density mapping using a grid shaped catheter allows for use of simultaneous analysis of adjacent orthogonal bipolar signals that may assist in more accurate substrate characterization and ablation strategy decisions. Purpose This was a prospective, multicenter observational study to characterize the utility of electroanatomical mapping with a high density grid-style mapping catheter (HD Grid) in subjects undergoing catheter ablation for persistent atrial fibrillation (PersAF) or ventricular tachycardia (VT) in real-world clinical settings. Methods Mapping was performed with the HD Grid catheter to generate high-density maps of cardiac chambers in order to assess the potential influence of the simultaneous orthogonal bipole configuration on PersAF and VT ablation strategies. Differences in substrate identification between simultaneous orthogonal bipole configuration and standard along-the-spline electrode configuration, and potential effects on ablation strategies were investigated. Results During the study period (January 2019 through April 2020), 367 subjects underwent catheter ablation for PersAF (N = 333, average age 64.1yr, 75% male) or VT (N = 34, average age = 64.3yr, 85.3% male). In total, 494 maps were generated to treat patients undergoing PersAF ablation and 57 to treat patients undergoing VT ablation. Compared to standard along-the-spline configuration, mapping with the simultaneous orthogonal bipole configuration showed differences in 57.8% (178/308) of maps generated, with the greatest difference noticed in surface area of low voltage (62.9%) and location of low voltage (55.6%). In comparisons performed live during the procedure (n = 50), simultaneous orthogonal bipole configuration assisted in identification of ablation targets in 70.0% of cases, changing the ablation strategy compared to that identified with along-the-spline configuration in 34.3%. In comparisons performed retrospectively after the procedure (n = 258), the ablation strategy identified with simultaneous orthogonal bipole configuration differed from along-the-spline configuration in 21.7% of maps. Even compared to a higher-density electrode configuration using all-bipoles rather than along-the-spline bipoles, simultaneous orthogonal bipole configuration identified differences in 57.1% of maps. Conclusion The HD grid catheter combined with simultaneous orthogonal bipole configuration can define myocardial substrate more accurately compared to standard along-the-spline configuration. The difference in substrate identification has potential impact on ablation strategy. Further clinical trials are needed to elucidate the role of orthogonal bipole configuration mapping and improved ablation success rates.

scholarly journals High‐density mapping of de novo focal atrial tachycardias using a new software: Protected low‐voltage areas by zones of conduction delay

2020 ◽  
Vol 36 (4) ◽  
pp. 785-788
Author(s):  
Konstantinos P. Letsas ◽  
Michael Efremidis ◽  
George Bazoukis ◽  
Stylianos Dragasis ◽  
Athanasia Megarisiotou ◽  
...  
Keyword(s):  
De Novo ◽  
Low Voltage ◽  
High Density ◽  
Conduction Delay ◽  
Density Mapping

scholarly journals 525Correlation of left atrial low voltage and fractionation substrate between sinus rhythm and atrial fibrillation: high density mapping study in persistent AF

EP Europace ◽  
2018 ◽  
Vol 20 (suppl_1) ◽  
pp. i100-i101
Author(s):  
J Chen ◽  
A Jadidi ◽  
Z Moreno-Weidmann ◽  
B Mueller-Edenborn ◽  
H Lehrmann ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Sinus Rhythm ◽  
Left Atrial ◽  
Low Voltage ◽  
High Density ◽  
Mapping Study ◽  
Density Mapping

scholarly journals P301Comparison of local activation time annotation algorithms in high density mapping of regular atrial tachycardias

EP Europace ◽  
2017 ◽  
Vol 19 (suppl_3) ◽  
pp. iii47-iii47
Author(s):  
J. De Pooter ◽  
M. Elhaddad ◽  
T. Phlips ◽  
L. Timmers ◽  
F. Van Heuverswyn ◽  
...  
Keyword(s):  
High Density ◽  
Activation Time ◽  
Local Activation ◽  
Density Mapping ◽  
Local Activation Time

P1036Acute and long-term ablation results of extra pulmonary vein drivers detected by ultra high density mapping on top of PVI in persistent AF

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
B Enache ◽  
D G Latcu ◽  
K Hasni ◽  
S S Bun ◽  
N Saoudi
Keyword(s):  
Pulmonary Vein ◽  
Low Voltage ◽  
Respiratory Gating ◽  
Persistent Atrial Fibrillation ◽  
High Density ◽  
Long Term Results ◽  
Contact Mapping ◽  
Density Mapping ◽  
Extra Pulmonary

Abstract Background Whether ultra-high density (UHD) contact mapping is useful in radiofrequency ablation of persistent atrial fibrillation (AF) is unknown. Purpose To sequentially map the left atrial (LA) activation during AF ablation (circumferential PVI and ablation of extra pulmonary vein drivers). Methods Time reference was an LA appendage (LAA) electrogram (EGM). Points were acquired with respiratory gating if reference, cycle length (10 ms tolerance) and electrode location were stable. For fragmented EGM the timing of the surrounding area was used. In case of extremely low voltage (<0.01 mV) or lack of local statistical coherence no colour-code was displayed (grey area). Circular propagation around single points was defined as organized rotating drivers (see figure). All pts had PVI followed by remapping and ablation of the centre of rotational regions and at sites with focal type propagation. DC or chemical cardioversion were not performed in the first 48 h. Results Out of 41 patients (pts) undergoing first time ablation with the above described protocol, 30 (66±8 y, mean current episode duration 8 months) were followed for a mean time of 14,7 months. At 48 hours post-procedure, 70% of pts were no longer in AF: 6 (20%) in sinus rhythm and 15 (50%) in atrial tachycardias. At 1 year after a single procedure, freedom from AF was 87% and freedom from AF and AT was 60%. Conclusion In persistent AF, sequential UHD activation mapping is useful in guiding and potentially improving long term results of ablation of extra pulmonary vein drivers after PVI.

P441Targeted ablation of residual luminal pulmonary vein potentials through high density mapping: preliminary results from the CHARISMA registry

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
F Solimene ◽  
F M Cauti ◽  
G Zucchelli ◽  
V Schillaci ◽  
P Rossi ◽  
...  
Keyword(s):  
Pulmonary Vein ◽  
De Novo ◽  
Low Voltage ◽  
Complete Characterization ◽  
High Density ◽  
Analysis Tool ◽  
Temporal Consistency ◽  
Af Ablation ◽  
Density Mapping

Abstract Background A high incidence of pulmonary vein (PV) reconnection has been reported in patients (pts) with clinical recurrences of AF. Low-voltage activity beyond PVs (e.g. antral activity) may contribute to ablation failures in the long term. Detailed characterization of PV antra through high density mapping (HDM) and automated algorithm is still lacking.  Purpose to characterize PV gaps and the low-voltage activity in tissue such as the PV antra during and after ablation of PVs in AF pts.  Methods Consecutive pts undergoing AF ablation from the CHARISMA registry with complete characterization of residual PV antral activity were included. A complete map of the left atrium and PVs was performed prior and after ablation through the Rhythmia HDM system. A novel map analysis tool (Lumipoint - LM -) that automatically identifies split potentials and continuous activation was used sequentially on each PV component, in order to assess the presence of gaps (PVG) and residual potential within the antral scar (RAP, defined as any low voltage high frequency fractionated signal propagating within the antral scar without conduction into the vein) and characterize electrical propagation. After ablation we reassessed with repeat voltage and propagation maps that electrical quiescence was achieved. Ablation endpoint was PV isolation.  Results Thirty-six cases of AF ablation were analyzed (11 de novo, 25 redo). A total of 36 PVG in 13 (36%) patients were detected after remap (1 case of de novo) or initial map of redo patients (12 cases). A total of 34 RAP in 20 cases (56%) were found: 4 (36%) cases of de novo (all after ablation and remap) and 16 (64%) cases of redo (all after initial map). In 7 (19%) cases we found at least one RAP in pts with complete absence of PV conduction. 100% of PVG (n = 36) and 89% of RAP (n = 29) were fully detected though a first pass automated annotation. In 5 RAPs (11%) an additional temporal consistency of low-voltage signal relative to neighboring activation was needed due to the very low voltage EGM (≤0.1 mV). PVGs were more common at right PV sites (n = 26, 72%) and anterior PV sites (n = 20, 55.6%) whereas RAPs were detected more frequently at left PV sites (n = 20, 59%) and anterior PV sites (n = 21, 62%). RAP showed a lower median voltage compared with PVG (0.22[0.2-0.3]mV for RAP vs 0.97[0.6-1.3]mV for PVG, p &lt; 0.0001) whereas the median number of EGM peaks were higher (6.5[5-8] for RAP vs 3[2-4] for PVG, p &lt; 0.0001). No complications during the procedures were reported. The acute procedural success was 100%, with all PVs successfully isolated and RAPs completely abolished in all study pts.  Conclusion In our preliminary experience, local vulnerabilities in antral lesion sets were commonly discernible using HDM system both in de novo or redo patients when no PV conduction was present. The applied workflow seemed to be useful to quickly pinpoint and accelerate the search of local PV activity or concealed low-voltage activity.

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