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.

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 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.

P1020Persistent AF patients with limited areas of low voltage have a similar benefit from pulmonary vein isolation as compared to paroxysmal AF patients: insight from the SMOP study

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
L Frigerio ◽  
A Sanzo ◽  
S Cornara ◽  
E Chieffo ◽  
C La Greca ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Pulmonary Vein ◽  
Pulmonary Vein Isolation ◽  
Statistical Difference ◽  
Low Voltage ◽  
High Density ◽  
P Value ◽  
Atrial Fibrosis ◽  
Density Mapping

Abstract Background Pulmonary vein isolation (PVI) performed with radio-frequency catheter ablation (CA) is an effective therapy for atrial fibrillation (AF). However previous data have suggested that PVI is less effective in persistent (PER) vs. paroxysmal (PAR) AF. Atrial fibrosis and scar, indeed, are an important substrate involved in persistent AF, and some author correlate them to an increased rate of recurrences after CA. For this reason several adjunctive ablation strategies have been suggested for invasive treatment in PER AF pts. However, there is a lack of evidence on their effectivness in current literature. Objective the aim of our study was to assess the rate of AF recurrences in PAR and PER AF patients after a first pulmonary vein isolation (IVP) procedure, and their relationship with low voltage areas of the left atrium assessed by means of high density mapping performed before CA. Methods we analyzed 214 patients of the SMOP-AF study (Substrate Mapping as Outcome Predictor in Atrial Fibrillation Ablation), a prospective multi-centric registry enrolling patients with both PAR and PER AF undergoing a first radio-frequency CA procedure aimed to obtain permanent PVI . High-density mapping was performed in sinus rhythm using the CARTO system before PVI. Areas with less than 0,5 mV on mapping were defined as low voltage zone (LVZ); LVZ was indexed on the atrial area. Comparisons were made by cross-tables and Chi-square test or Student T test. Results Patients with PER AF (n = 44, 21%) were older (63 ± 9 vs 58 ± 10 yrs, p = 0.01), but notably with no difference in LVEF and atrial dimensions as compared to pts with PAR AF. In addition no statistical difference was observed in procedural variables, except for a greater LVZ area on atrial mapping (8 ± 18 % vs. 5 ± 15 %, p = 0.04) and a longer p wave duration (115 ± 21 msec vs. 103 ± 18 msec, p = 0.01) in pts with PER AF. The incidence of recurrence in the overall population was 15.3% at 3 months and 13.7% from 3 to 12 months: there was no statistical difference in success-rate between PER and PAR pts (respectively 79,5% vs 86% p value = 0.315 in blanking period and 85,3% vs 86,5% p value = 0.8 at 3-12 months follow-up). No statistical difference was observed for ablation variables (number of lesion, contact force, force time integral) in pts with vs. without recurrences. Conclusion Our study showed that pulmonary vein isolation alone seems to be as effective in paroxismal and persistent AF patients with low degree of left atrial fibrosis. Our data call into question the idea that PVI alone is not effective in PER AF. High density mapping of the LA could help to identify a subset of PER AF patients with a limited extension of low voltage areas (i.e around 10% of the overall LA surface) that could benefit from PVI without adjunctive ablation strategies. Our data needs to be confirmed in a longer follow-up.

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.

P3778Long-term outcome of non-pharmacologial treatment of atrial fibrillation in hypertrophic cardiomyopathy: a large single-centre experience

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
L Dinshaw ◽  
M Lemoine ◽  
J Hartmann ◽  
B Schaeffer ◽  
N Klatt ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Catheter Ablation ◽  
Left Atrial ◽  
High Density ◽  
Term Outcome ◽  
Long Term Outcome ◽  
Density Mapping ◽  
Ablation Success

Abstract Introduction Atrial fibrillation (AF) is common in hypertrophic cardiomyopathy (HCM) and is generally associated with a significant deterioration of clinical status. Non-pharmacological treatment such as surgical and catheter ablation has become an established therapy for symptomatic AF but in patients with HCM often having a chronically increased left atrial pressure and extensive atrial cardiomyopathy the long-term outcome is uncertain. Purpose The present study aimed to analyse the long-term outcome of AF ablation in HCM and the mechanism of recurrent atrial arrhythmias using high-density mapping systems. Methods A total of 65 patients (age 64.5±9.9 years, 42 (64.6%) male) with HCM undergoing AF ablation for symptomatic AF were included in our study. The ablation strategy for catheter ablation included pulmonary vein isolation in all patients and biatrial ablation of complex fractionated electrograms with additional ablation lines if appropriate. In patients with suspected atrial tachycardia (AT) high-density activation and substrate mapping were performed. A surgical ablation at the time of an operative myectomy for left ventricular outflow tract obstruction was performed in 8 (12.3%) patients. The outcome was analysed using clinical assessment, Holter ECG and continuous rhythm monitoring of cardiac implantable electric devices. Results Paroxysmal AF was present in 27 (41.6%), persistent AF in 37 (56.9%) and primary AT in 1 (1.5%) patients. The mean left atrial diameter was 54.1±12.5 ml. In 11 (16.9%) patients with AT high-density mapping was used to characterize the mechanism of the ongoing tachycardia. After 1.9±1.2 ablation procedures and a follow-up of 48.5±37.2 months, ablation success was demonstrated in 58.9% of patients. The success rate for paroxysmal and persistent AF was 70.0% and 55.8%, respectively (p=0.023). Of those patients with AT high-density mapping guided ablation was successful in 44.4% of patients. The LA diameter of patients with a successful ablation was smaller (52.2 vs. 58.1 mm; p=0.003). Conclusion Non-pharmacological treatment of AF in HCM is effective during long-term follow-up. Paroxysmal AF and a smaller LA diameter are favourable for successful ablation. In patients with complex AT the use of high-density mapping can guide ablation resulting in further ablation success in a reasonable number of patients.

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

P1037Relationship between left atrium low voltage areas and atrial fibrillation radiofrequency ablation success-rate: preliminary results of the SMOP study

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
R Rordorf ◽  
S Cornara ◽  
L Frigerio ◽  
A Sanzo ◽  
E Chieffo ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Radio Frequency ◽  
Success Rate ◽  
Left Atrium ◽  
Low Voltage ◽  
Left Ventricular ◽  
High Density ◽  
Left Ventricular Ejection ◽  
P Value ◽  
Short Term

Abstract Background radio frequency catheter ablation (CA) is an effective therapy for atrial fibrillation (AF). Some authors have described a potential relationship between the presence of areas of fibrosis in the left atrium (LA) and the success of CA, nevertheless there is a lack of multicenter studies in this field. Objective the aim of our study was to assess the relationship between the of presence of low voltage areas of the LA detected during subtrate mapping at the time of the procedure and recurrences of AF after CA. Methods we analyzed 214 patients of the SMOP-AF (Substrate Mapping as Outcome Predictor in Atrial Fibrillation Ablation), a prospective multi-centric study enrolling patients with both paroxysmal and persistent AF undergoing a first radio-frequency CA procedure. High-density mapping was performed in sinus rhythm using the CARTO system before performing pulmonary vein isolation. Areas with less than 0,5 mV on mapping were defined as low voltage zone (LVZ), while between 0,5 mV and 1,5 mV intermediate voltage zone (IVZ). IVZ and LVZ were expressed as a percentage of the LA surface. Comparisons were made by Pearson correlation, cross-tables and Chi-square test or Student T test. Results the mean age of the enrolled population was 59±9 years, left ventricular ejection fraction was 59±9%, 86.4% of the pts had tested at least one anti-arrhythmic drug. Persistent atrial fibrillation was present in 10.3% of patients. The rate of documented AF recurrence at 3 months was 15,3% (n=29). There was a statistical significant correlation between the presence of IVZ and the rate of recurrences at 3 months (r=0.16, p value 0.03). Patients with IVZ greater than 4% of the left atrium surface showed a higher risk of recurrences (19.5% vs. 8,7%, p value 0.04). No statistical difference was observed in other procedural variables (number of lesions, contact force, force-time integral) among patients with or without recurrences. Conclusion Our study showed a relationship between CA short-term success rate and the presence of areas of intermediate voltage zone detected with high-density substrate mapping at the time of the procedure. The presence of areas of intermediate voltage zone greater than 4% of the LA determines a 2.5 folds increased risk of short-term recurrence. Our data needs to be confirmed in a longer follow-up.

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