scholarly journals Epicardial voltage mapping in patients with postinfarction ventricular tachycardia: a pilot study

2020 ◽  
Vol 27 ◽  
pp. 22-27
Author(s):  
K. A. Simonova ◽  
E. N. Mikhaylov ◽  
R. B. Tatarskiy ◽  
A. V. Kamenev ◽  
D. V. Panin ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Ventricular Tachycardia ◽  
Low Voltage ◽  
Epicardial Mapping ◽  
Voltage Mapping ◽  
Arrhythmogenic Substrate ◽  
Ablation Success ◽  
History Of ◽  
Ventricular Activity ◽  
Epicardial Access

Introduction. Radiofrequency ablation (RFA) is an established treatment of post-myocardial infarction ventricular tachycardia (VT). Endocardial VT ablation can be insufficient for VT termination when the scar is intramural/epicardial.Purpose: to assess the extent of epicardial electrophysiological VT substrate in patients with remote myocardial infarction.Materials and methods. Thirteen patients with sustained postinfarction VT, who signed an informed consent, were included into the study. All patients underwent full clinical evaluation. Electroanatomical voltage bi- and unipolar mapping of endocardial and epicardial surfaces was performed. Maps were evaluated for the presence of low-voltage areas and local abnormal ventricular activity (LAVA). RFA was performed at LAVA sites. The end-point of the procedure was scar LAVA abolition and VT noninducibility (procedure success). VT recurrence was detected using an implantable cardioverter-defibrillator and/or ECG monitoring.Results. Epicardial access was successful in 12 patients. Epicardial access was performed at a first procedure in 7 patients, 4 patients had a history of previous endocardial ablation. Epicardial LAVA sites were detected in 9 patients. Endocardial and epicardial arrhythmogenic substrate localization coincided in 8 patients. One patient had only epicardial scar, 1 patient had only septal endocardial scar. In one patient LAVA sites had different localizations on epicardial and endocardial maps. Acute ablation success was noted in 12 patients.Conclusion. In our patient group transmural scar and epicardial electrophysiological arrhythmogenic substrate was detected in 82% of cases. Isolated endocardial ablation may be unsuccessful, in such cases epicardial mapping and ablation might be useful.

P357Epicardial abnormal electrical activity in unselected patients with ischemic ventricular tachycardia: a pilot mapping study

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
K Simonova ◽  
E N Mikhaylov ◽  
R B Tatarskiy ◽  
A V Kamenev ◽  
D V Panin ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Ventricular Tachycardia ◽  
Catheter Ablation ◽  
Left Ventricle ◽  
Electrical Activity ◽  
Inferior Wall ◽  
Scar Area ◽  
Epicardial Surface ◽  
Arrhythmogenic Substrate ◽  
Epicardial Access

Abstract Background radiofrequency catheter ablation (RFA) on the endocardial ventricular surface is widely used for post-myocardial infarction (post-MI) ventricular tachycardia (VT) treatment. It has been described that about 10% of patients with post-MI require additional epicardial ablation for successful VT termination. However, there is still lack of data regarding the extent of scarring and the presence of local abnormal ventricular electrical activity (LAVA, low-voltage and/or fractionated signals) on the epicardial surface in patients with ischemic VT. Purpose to assess the extent of epicardial electrophysiological substrate in patients with remote myocardial infarction and indications for VT ablation. Methods thirteen out of 59 patients with sustained ischemic VT (12 men; mean age 59,9 ± 9,5) and without previous cardiac surgery signed an informed consent to undergo epicardial mapping and comprized the study population. Endocardial access was used previously as primary method in 4 patients  ICD/ CRT-D had been previously implanted in 11 patients: mean left ventricle ejection fraction was 38,8 ± 10,6 %: hemodynamically unstable VT was present in 10 patients; the most frequent scar localization by ECG and transthoracic echocardiography – left ventricle (LV) inferior wall (10 patients), LV lateral wall – (7 patients). All patients underwent full clinical evaluation. Electrophysiological procedure and catheter ablation was performed under general anesthesia. Epicardial access was obtained through percutaneous subxyphoid puncture. Voltage mapping of endocardial and epicardial surfaces was performed. Maps were evaluated for the presence of LAVA. Ablation was performed at sites of LAVA on either side of the ventricular wall. Results epicardial access was successful in 12 patients. Bi- and unipolar mapping was successfully performed and analyzed in 11 subjects. LAVA was present in all but one patient on endocardial surface and in 9 (82%) out of 12 patients on epicardial surface. Localization of endocardial and epicardial LAVA coincided in 8 (67%) patients suggesting transmural ischemic scar. One patient had only epicardial scar, 1 patient had septal endocardial scar without LAVA on the epicardial surface. In one patient LAVA sites were localized on different left ventricle walls. More extensive unipolar than bipolar endocardial scar area was found (11,8 (IQR:2,0;31,6) vs 45,8 (IQR:17,1;86,5) сm2; р=0,03). Epicardial unipolar scar area prevailed over bipolar scar area: median 46.0 cm2 (IQR: 15.9;55.5) vs 107.7 cm2 (IQR: 84.3;168.9) р=0,04. LAVA epicardial area was wider than endocardial: 19.7 cm2 (IQR: 2.3; 29.7) vs 4.1 cm2 (IQR: 0.4; 23.8) р=0.03. Conclusion according to the results of our pilot study in unselected patients with ischemic VT, epicardial arrhythmogenic substrate was detected in 82% of cases. Epicardial LAVA area significantly prevailed over endocardial LAVA area.

scholarly journals Identification of Low-voltage Areas: A Unipolar, Bipolar and Omnipolar Perspective

2021 ◽  
Author(s):  
Mathijs S. van Schie ◽  
Rohit K. Kharbanda ◽  
Charlotte A. Houck ◽  
Eva A.H. Lanters ◽  
Yannick J.H.J. Taverne ◽  
...  
Keyword(s):  
Low Voltage ◽  
Volume Overload ◽  
Surrogate Markers ◽  
Epicardial Mapping ◽  
Atrial Volume ◽  
Bipolar Voltage ◽  
Voltage Mapping ◽  
Arrhythmogenic Substrate ◽  
Different Types ◽  
Mapping Techniques

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.

scholarly journals Endocardial vs endo-epicardial ablation of ventricular arrhythmia in arrhythmogenic right ventricular cardiomyopathy: a single center experience

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
K.A Simonova ◽  
A.V Kamenev ◽  
R.B Tatarskiy ◽  
M.A Naymushin ◽  
V.S Orshanskaya ◽  
...  
Keyword(s):  
Ventricular Arrhythmia ◽  
Low Voltage ◽  
Arrhythmogenic Right Ventricular Cardiomyopathy ◽  
Control Group ◽  
Definite Diagnosis ◽  
Premature Ventricular Contractions ◽  
Single Center Experience ◽  
Voltage Mapping ◽  
Epicardial Access

Abstract Background The majority of patients have a sub-epicardial scar as a substrate for VT episodes. Purpose We sought to compare the efficacy of endocardial (ENDO) and epicardial (EPI) substrate modification in patients with ARVC. Methods 20 consecutive ARVC patients (mean age 41,4±13,8, 70% males; ICD previously implanted in 10 patients) with indications to ventricular arrhythmia ablation (RFA) were included into a prospective observational study. The EPI group consisted of 10 patients with sustained ventricular tachycardia (VT) (definite diagnosis ARVC – 8 patients; borderline – 1, possible – 1) who signed an informed consent to epicardial access. The ENDO group included 10 patients (definite diagnosis ARVC – 9 patients), five of them demonstrated sustained VT and 5 patients had frequent symptomatic premature ventricular contractions (PVC). Epicardial access in the EPI group was obtained through subxyphoid puncture. Bi- and unipolar voltage mapping of endocardial and epicardial surfaces was performed. Maps were evaluated for the presence of local abnormal ventricular electrical activity (LAVA, low-voltage areas and sites with highly fractionated or late activity). Ablation was performed at sites of LAVA on either side of the ventricular wall. In the ENDO group endocardial only ablation at LAVA sites was performed. RF energy ablation was 40W at the epicardial surface and 40–50W at the endocardial surface. Results In the EPI group endocardially mapped area of unipolar endocardial low voltage zone (LVZ) significantly prevailed over bipolar endocardial area of LVZ: 75.4 cm2 [IQR: 23.2; 211.9] vs 6.7 cm2 [IQR: 4.4; 35.5](P=0.009). Epicardial bipolar LVZ area prevailed over unipolar epicardial LVZ area: 65.3 cm2 [IQR: 55.6; 91.3] vs 6.7 cm2 [IQR: 4.4; 35.3] (P=0.005). Endocardial unipolar LVZ area in the EPI group was larger than in the ENDO group (P&gt;0,05). After ablation non-inducibility of any ventricular arrhythmia was achieved in 90% of patients in the EPI group and in 80% of cases in the ENDO group. During a mean follow-up period of 22.3±10.5 months freedom of ventricular arrhythmia recurrence was 70% in the EPI group and 100% in the control group. Conclusions Although epicardial area of abnormal potentials significantly prevails over endocardial area, endocardial unipolar mapping and higher RF ablation power allow performing successful ventricular arrhythmia treatment in the majority of ARVC patients. Funding Acknowledgement Type of funding source: None

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 ◽  
...  
Keyword(s):  
Low Voltage ◽  
3D Mapping ◽  
Bipolar Voltage ◽  
Voltage Mapping ◽  
Arrhythmogenic Substrate ◽  
Mapping System ◽  
3D Mapping System ◽  
Modest Correlation

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.

Low-voltage bridge strategy to guide cryoablation of typical and atypical atrioventricular nodal re-entry tachycardia in children: mid-term outcomes in a large cohort of patients

EP Europace ◽  
2020 ◽  
Author(s):  
Fabrizio Drago ◽  
Camilla Calvieri ◽  
Mario Salvatore Russo ◽  
Romolo Remoli ◽  
Vincenzo Pazzano ◽  
...  
Keyword(s):  
Recurrence Rate ◽  
Low Voltage ◽  
Electrophysiological Study ◽  
Large Cohort ◽  
Definitive Treatment ◽  
Lesion Length ◽  
Voltage Mapping ◽  
Arrhythmogenic Substrate ◽  
Catheter Tip ◽  
Procedural Success

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.

scholarly journals Comparison of Unipolar and Bipolar Voltage Mapping for Localization of Left Atrial Arrhythmogenic Substrate in Patients With Atrial Fibrillation

2020 ◽  
Vol 11 ◽  
Author(s):  
Deborah Nairn ◽  
Heiko Lehrmann ◽  
Björn Müller-Edenborn ◽  
Steffen Schuler ◽  
Thomas Arentz ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Left Atrial ◽  
Low Voltage ◽  
High Density ◽  
Border Zone ◽  
Electrode Spacing ◽  
Bipolar Voltage ◽  
Voltage Mapping ◽  
Arrhythmogenic Substrate ◽  
The Impact

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 (&gt;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: &lt;0.5 and &lt;1 mV in SR, &lt;0.35 and &lt;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 &lt;0.5 mV in SR and 42 ± 26 cm2 at &lt;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.

Endocardial and epicardial mapping and catheter ablation of post myocardial infarction ventricular tachycardia

2010 ◽  
Vol 28 (2) ◽  
pp. 137-145 ◽  
Author(s):  
Mauricio Arruda ◽  
Tamer Fahmy ◽  
Luciana Armaganijan ◽  
Luigi Di Biase ◽  
Dimpi Patel ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Ventricular Tachycardia ◽  
Catheter Ablation ◽  
Post Myocardial Infarction ◽  
Epicardial Mapping
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