Abstract 18572: Limitations of Endocardial Unipolar Voltage Mapping in Predicting the Epicardial Substrate

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Yalçin Gökoglan ◽  
Mahmut F Günes ◽  
Luigi Di Biase ◽  
Carola Gianni ◽  
Sanghamitra Mohanty ◽  
...  

Introduction: Bipolar voltage mapping detects areas of scar and guides ablation of VT. The role of endocardial unipolar voltage mapping is not well defined. We examined the endo-epicardial substrate in a mixed cohort of patients with structural heard disease (SHD) to determine whether an endocardial unipolar low voltage area predicts the presence and location of an epicardial scar. Results: Data from 24 consecutive patients with SHD (11 ICM, 6 NICM, 3 HCM, 2 ARVC, 1 myocarditis, 1 Brugada) with a detailed (mean points per map 200) combined endocardial-epicardial substrate mapping were retrospectively reviewed. Maps were obtained using a 3D mapping system (CARTO 3) and normal thresholds used were ≤1.5 mV for bipolar voltage, and ≤5.5 (RV) or ≤8.3 mV (LV) for unipolar voltage. Mapping was performed in the LV in 17 patients, in the RV in 6 patients, in both in 1 patient. An endocardial unipolar low voltage area was found in 21/25 maps. In 12/21 maps there was no corresponding epicardial scar, while in 3/4 cases an epicardial scar was detected despite a negative unipolar map (PPV=43%, NPV=25%, P=NS; Fig. 1). In the 9 cases with both positive endocardial unipolar and epicardial bipolar maps, the epicardial scar was found in the corresponding ventricular region of the endocardial low-voltage area, although unipolar area had a tendency to overestimate the area of the scar (115 vs 95 cm 2 ). Conclusion: In this series of patients with SHD, analysis of unipolar voltage maps could not reliably predict the epicardial arrhythmogenic substrate. There is a modest correlation between areas of endocardial unipolar low voltage and epicardial scars (57% of patients with an abnormal unipolar map had a normal epicardial substrate). Moreover, an epicardial substrate cannot be safely excluded based on a normal unipolar endocardial map. Fig. 1 Abnormal bipolar epicardial map (left) with corresponding normal unipolar endocardial map (right) in a patient with ARVC. Pink dots represent area of defragmentation.

2020 ◽  
Vol 11 ◽  
Author(s):  
Deborah Nairn ◽  
Heiko Lehrmann ◽  
Björn Müller-Edenborn ◽  
Steffen Schuler ◽  
Thomas Arentz ◽  
...  

Background: Presence of left atrial low voltage substrate in bipolar voltage mapping is associated with increased arrhythmia recurrences following pulmonary vein isolation for atrial fibrillation (AF). Besides local myocardial fibrosis, bipolar voltage amplitudes may be influenced by inter-electrode spacing and bipole-to-wavefront-angle. It is unclear to what extent these impact low voltage areas (LVA) in the clinical setting. Alternatively, unipolar electrogram voltage is not affected by these factors but requires advanced filtering.Objectives: To assess the relationship between bipolar and unipolar voltage mapping in sinus rhythm (SR) and AF and identify if the electrogram recording mode affects the quantification and localization of LVA.Methods: Patients (n = 28, 66±7 years, 46% male, 82% persistent AF, 32% redo-procedures) underwent high-density (>1,200 sites, 20 ± 10 sites/cm2, using a 20-pole 2-6-2 mm-spaced Lasso) voltage mapping in SR and AF. Bipolar LVA were defined using four different thresholds described in literature: <0.5 and <1 mV in SR, <0.35 and <0.5 mV in AF. The optimal unipolar voltage threshold resulting in the highest agreement in both unipolar and bipolar mapping modes was determined. The impact of the inter-electrode distance (2 vs. 6 mm) on the correlation was assessed. Regional analysis was performed using an 11-segment left atrial model.Results: Patients had relevant bipolar LVA (23 ± 23 cm2 at <0.5 mV in SR and 42 ± 26 cm2 at <0.5 mV in AF). 90 ± 5% (in SR) and 85 ± 5% (AF) of mapped sites were concordantly classified as high or low voltage in both mapping modes. Discordant mapping sites located to the border zone of LVA. Bipolar voltage mapping using 2 vs. 6 mm inter-electrode distances increased the portion of matched mapping points by 4%. The unipolar thresholds (y) which resulted in a high spatial concordance can be calculated from the bipolar threshold (x) using following linear equations: y = 1.06x + 0.26mV (r = 0.994) for SR and y = 1.22x + 0.12mV (r = 0.998) for AF.Conclusion: Bipolar and unipolar voltage maps are highly correlated, in SR and AF. While bipole orientation and inter-electrode spacing are theoretical confounders, their impact is unlikely to be of clinical importance for localization of LVA, when mapping is performed at high density with a 20-polar Lasso catheter.


Author(s):  
Mathijs S. van Schie ◽  
Rohit K. Kharbanda ◽  
Charlotte A. Houck ◽  
Eva A.H. Lanters ◽  
Yannick J.H.J. Taverne ◽  
...  

Background - Low-voltage areas (LVA) are commonly considered surrogate markers for an arrhythmogenic substrate underlying tachyarrhythmias. It remains challenging to define a proper threshold to classify LVA and it is unknown whether unipolar, bipolar and the recently introduced omnipolar voltage mapping techniques are complementary or contradictory in classifying LVAs. Therefore, this study examined similarities and dissimilarities in unipolar, bipolar and omnipolar voltage mapping and explored the relation between various types of voltages and conduction velocity (CV). Methods - Intra-operative epicardial mapping (interelectrode distance 2mm, ±1900 sites) was performed during sinus rhythm in 21 patients (48±13 years, 9 male) with atrial volume overload. Cliques of 4 electrodes (2x2 mm) were used to calculate the maximal unipolar (V uni,max ), bipolar (V bi,max ) and omnipolar (V omni,max ) voltages and mean CV. Areas with V bi,max or V omni,max ≤0.5 mV were defined as LVA. Results - V uni,max was not only larger than V bi,max but also larger than V omni,max (7.08 [4.22-10.59] mV vs. 5.27 [2.39-9.56] mV and 5.77 [2.58-10.52] mV respectively, P<0.001). In addition, the largest bipolar clique voltage was on average 1.66 (range: 1.0 - 59.0) times larger to the corresponding perpendicular bipolar voltage pair. LVAs identified by a bipolar or omnipolar threshold corresponded to a broad spectrum of unipolar voltages and, even though CV was generally decreased, still high CVs and large unipolar voltages were found in these LVAs. Conclusions - In patients with atrial volume overload, there were considerable discrepancies in the different types of LVAs. Additionally, identification of LVAs was hampered by considerable directional differences in bipolar voltages. Even using directional independent omnipolar voltage to identify LVAs, high CVs and large unipolar voltages are present within these areas. Therefore, a combination of low unipolar and low omnipolar voltage may be more indicative of 'true' LVAs.


2012 ◽  
Vol 1 ◽  
pp. 59 ◽  
Author(s):  
Stephen P Page ◽  
Mehul Dhinoja ◽  
◽  

Novel technologies have been developed recently to assess contact between the ablation catheter and the underlying tissue in an attempt to improve safe and effective lesion delivery. The most recently developed technology is the SmartTouch™ catheter which is an open irrigated-tip catheter integrated within the CARTO 3 3D mapping system. In this review we consider the role of contact force technology, evaluate the published data and discuss the potential applications of this novel technology.


2021 ◽  
Vol 30 (4) ◽  
pp. 626-628
Author(s):  
Katherine Romanowicz ◽  
Muhammad Athar ◽  
Alexandru Costea

Author(s):  
Navan Tanjeem Hossain ◽  
Rahat Mahmood Khan ◽  
Saifur Rahman ◽  
Md. Ziaur Rahman Khan

EP Europace ◽  
2020 ◽  
Author(s):  
Fabrizio Drago ◽  
Camilla Calvieri ◽  
Mario Salvatore Russo ◽  
Romolo Remoli ◽  
Vincenzo Pazzano ◽  
...  

Abstract Aims In the current literature, results of the low-voltage bridge (LVB) ablation strategy for the definitive treatment of atrioventricular nodal re-entry tachycardia (AVNRT) seem to be encouraging also in children. The aims of this study were (i) to prospectively evaluate the mid-term efficacy of LVB ablation in a very large cohort of children with AVNRT, and (ii) to identify electrophysiological factors associated with recurrence. Methods and results One hundred and eighty-four children (42% male, mean age 13 ± 4 years) with AVNRT underwent transcatheter cryoablation guided by voltage mapping of the Koch’s triangle. Acute procedural success was 99.2% in children showing AVNRT inducibility at the electrophysiological study. The overall recurrence rate was 2.7%. The presence of two LVBs, a longer fluoroscopy time and the presence of both typical and atypical AVNRT, were found to be significantly associated with an increased recurrence rate during mid-term follow-up. Conversely, there was no significant association between recurrences and patient’s age, type of LVB, lesion length, number of cryolesions or catheter tip size. Conclusion The LVB ablation strategy is very effective in AVNRT treatment in children. Recurrences are related to the complexity of the arrhythmogenic substrate.


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