Newer Methods for VT Ablation and When to Use Them

Abstract Aims Ventricular tachycardia (VT) substrate-based ablation has become a standard procedure. Electroanatomical mapping (EAM) detects scar tissue heterogeneity and define conduction channels (CCs) that are the ablation target. Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) is able to depict CCs and increase ablation success. Most patients undergoing VT ablation have an implantable cardioverter-defibrillator (ICD) that can cause image artefacts in LGE-CMR. Recently wideband (WB) LGE-CMR sequence has demonstrated to decrease these artefacts. The aim of this study is to analyse accuracy of WB-LGE-CMR in identifying the CC entrances. Methods and results Thirteen consecutive ICD-patients who underwent VT ablation after WB-LGE-CMR were included. Number and location of CC entrances in three-dimensional EAM and in WB-LGE-CMR reconstruction were compared. Concordance was compared with a historical cohort matched by cardiomyopathy, scar location, and age (26 patients) with LGE-CMR prior to ICD and VT ablation. In WB-CMR group, 101 and 93 CC entrances were identified in EAM and WB-LGE-CMR, respectively. In historical cohort, 179 CC entrances were identified in both EAM and LGE-CMR. The EAM/CMR concordance was 85.1% and 92.2% in the WB and historical group, respectively (P = 0.66). There were no differences in false-positive rate (CC entrances detected in CMR and absent in EAM: 7.5% vs 7.8% in WB vs. conventional CMR, P = 0.92) nor in false-negative rate (CC entrances present in EAM not detected in CMR: 14.9% vs.7.8% in WB vs. conventional CMR, P = 0.23). Epicardial CCs was predictor of poor CMR/EAM concordance (OR 2.15, P = 0.031). Conclusion Use of WB-LGE-CMR sequence in ICD-patients allows adequate VT substrate characterization to guide VT ablation with similar accuracy than conventional LGE-CMR in patients without an ICD.

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

EP Europace ◽

10.1093/europace/euab116.061 ◽

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.

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Abstract 16187: Validation of Novel Algorithm to Automate Detection of Fractionated Electrograms During Ventricular Tachycardia (VT) Ablation

Circulation ◽

10.1161/circ.132.suppl_3.16187 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Pouria Alipour ◽

Yaariv Khaykin ◽

Meysam Pirbaglou ◽

Paul Ritvo ◽

Gal Hayam ◽

...

Keyword(s):

Ventricular Tachycardia ◽

Area Under The Curve ◽

High Sensitivity ◽

Left Ventricular ◽

Target Area ◽

Automate Detection ◽

Noise Threshold ◽

Vt Ablation ◽

Patient At Risk ◽

Novel Algorithm

Introduction: Ablation of ventricular tachycardia (VT) substrate in patient at risk for VT in the setting of ischemic heart disease is a technically challenging procedure. We thought to evaluate a novel algorithm used to automatically identify target electrograms. Methods: 16 consecutive patients (70±10 years of age, 90% male, 34±18% LV EF) had 20 ablations for ischemic VT using CARTO 3 mapping system over 2 years. Left ventricular (LV) substrate was mapped during right ventricular (RV) apical stimulation. Navistar Thermocool 3.5 mm irrigated tip catheters were used in all patients. A novel algorithm counting the number of electrogram deflections (NOD) crossing the 0.05mV noise threshold and duration of time from first to last such deflection during the window of interest (total fractionation time, TFT) was applied to all acquired maps after ablation was complete. Snapshots of 200 electrograms representing the high and low end of TFT and NOD values were presented to a group of 8 electrophysiologists experienced in VT ablation who were asked to select electrograms they would target for substrate ablation. The diagnostic accuracy of TFT and NOD values was then analysed. Results: Across the range of TFT values (0.0-281.0 ms), a cut-off value of 49.0 ms (81.6% sensitivity, 57% specificity) was established as an optimal indicator of an ablation target. Area under the curve for TFT was 0.675 (95% CI: 0.59-0.75, p=0.001). For NOD values (0.0-70.0 deflections), a cut off of 4.5 deflections (88.0% Sensitivity, 57 % specificity) was established as an optimal indicator of an ablation target. The area under the curve for NOD yielded an area of 0.75 (95% CI: 0.68-0.82, P=0.001). For TFT-NOD product as a variable, a cut-off value of 64 (91.0% Sensitivity, 52.4 % specificity) an optimal indicator of an ablation target. The Area under the curve for NOD and TFT multiple was 0.72 (95% CI: 0.65-0.80, P=0.001). Conclusion: A novel algorithm may be able to automatically classify LV substrate during mapping and ablation of ischemic VT with high sensitivity and acceptable specificity.

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Abstract 9860: Safety and Clinical Outcome of Catheter Ablation of Ventricular Arrhythmias Using Contact Force Sensing, Consecutive Case Series

Circulation ◽

10.1161/circ.132.suppl_3.9860 ◽

2015 ◽

Vol 132 (suppl_3) ◽

Author(s):

Astrid A Hendriks ◽

Ferdi Akca ◽

Lara Dabiri Abkenari ◽

Muchtiar Khan ◽

Rohit E Bhagwandien ◽

...

Keyword(s):

Contact Force ◽

Ventricular Arrhythmias ◽

Case Series ◽

Long Term Outcome ◽

Major Complications ◽

Acute Success ◽

Vt Ablation ◽

Procedural Success

Introduction: Poor catheter-to-myocardial contact can lead to ineffective ablation lesions and suboptimal outcome. Contact force (CF) sensing catheters in ventricular tachycardia (VT) ablations has not been studied for their long term efficacy. Hypothesis: The hypothesis is that CF ablation is superior to manual ablation (MAN) and non-inferior to remote magnetic navigation (RMN) ablation for safety and efficacy in acute and long term outcome. Methods: A total of 249 consecutive patients underwent VT ablation, with the use of MAN, CF or RMN catheters were included in this single center cohort study from January 2007 until March 2014. The primary endpoints were procedural success, acute major complications and VT recurrences at follow-up. The average follow-up period was ± 20 months. Results: Acute success was achieved in 191 out of 249 procedures (75.9%). Acute success in manual ablation, CF ablation and RMN ablation was 70.1%, 72.3% and 85.2% respectively (P = 0.038). Major complications occurred in 3.2% and there was a trend towards less major complications (P = 0.055) in the RMN group. Thirty-six percent of the patients with an initially successful procedure had a recurrence during follow-up (CF 41.2% MAN 37.5% RMN 32.0% P = NS). Conclusions: The use of CF sensing catheters does not improve the procedural outcome or safety profile in comparison to non-CF sensing ablation in ventricular arrhythmias. RMN non-CF sensing ablation has the highest procedural success rate. Future studies are necessary to investigate the role of CF in VT ablation and to define the optimal force.

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Abstract 17191: Intraprocedural Dobutamine Use is Independently Associated With Prolonged Length of Stay (LOS) Following Ventricular Tachycardia (VT) Ablation

Circulation ◽

10.1161/circ.138.suppl_1.17191 ◽

2018 ◽

Vol 138 (Suppl_1) ◽

Author(s):

Jeffrey D Graham ◽

Michael Rosenberg ◽

Amneet Sandhu ◽

Alexis Tumolo ◽

Wendy Tzou ◽

...

Keyword(s):

Length Of Stay ◽

Patient Characteristics ◽

Hospital Length ◽

Hospital Length Of Stay ◽

Impact Factors ◽

Vasoactive Drugs ◽

Prolonged Length ◽

Procedural Time ◽

Minimal Data ◽

Vt Ablation

Introduction: Use of inotropes such as dobutamine remains controversial in the management of heart failure (HF) due to uncertain efficacy and lack of mortality benefit. Furthermore, vasoactive drugs are frequently utilized during VT ablations despite minimal data regarding their effects on outcomes. Vasoactive drugs may impact factors such as long-term VT recurrences and hospital length of stay. Hypothesis: We sought to evaluate the hypothesis that the use of dopamine, dobutamine or phenylephrine have differential effects on outcomes after VT ablations. Methods: A retrospective analysis was completed for all VT ablations from 2013-17 at our institution. Patient characteristics and procedural details were collected for 149 VT ablation cases. Results: The cohort was 81% male, and 67% had cardiomyopathy of which 53% were ischemic with a mean EF of 29% (CI 26.7- 31.4). Average procedure time was 368 minutes (CI 347-388). Vasoactive drugs were used in 87% of patients undergoing VT ablation: phenylephrine (67%), dopamine (40%), dobutamine (37%). The median LOS for all patients was 5 days (mean 7 days, range 1 - 56 days, IQR 2 - 9 days). After adjusting for inducibility, HF and procedural time, the dose of dobutamine, but not dopamine or phenylephrine, was significantly associated with increased length of stay (Fig. 1a). Inducible VT at the end of the procedure also correlated with increased LOS (5.4±0.3 vs 8.6±0.3, p < 0.0001). Procedural time did not associate with increased LOS. Of all covariates, only the number of VTs induced during the procedure was significantly associated with increased VT recurrence (HR 1.22/VT morphology (CI 1.11-1.34, p < 0.001)). Conclusions: Dobutamine, but not phenylephrine or dopamine, was significantly associated with increased length of stay after adjusting for HF, procedural time and inducibility of VT. More research is needed regarding vasoactive drug use in VT ablations and their significance to procedural and post-procedure outcomes.

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Abstract 17420: First Clinical Experience of Novel MRI Artifact Suppression Sequence in ICD Patients Undergoing Scar Delineation for Ventricular Tachycardia (VT) Ablation

Circulation ◽

10.1161/circ.130.suppl_2.17420 ◽

2014 ◽

Vol 130 (suppl_2) ◽

Author(s):

Mohammed S Abdulghani ◽

Ramazan Asoglu ◽

T. Shin ◽

R. Gullpalli ◽

Rui Huang ◽

...

Keyword(s):

Low Voltage ◽

Pulse Sequence ◽

Metal Artifacts ◽

Preparation Pulse ◽

Signal Void ◽

Artifact Suppression ◽

Vt Ablation ◽

The Right ◽

Lge Cmr ◽

Cmr Imaging

Background: Recent studies have suggested that CMR imaging can be safely performed in selected patients with implanted ICDs. However, metal artifacts significantly impact the evaluation of myocardial fibrosis when using standard late gadolinium enhanced (LGE) protocols. Methods: 10 continuous patients scheduled for VT ablation underwent LGE CMR imaging (1.5T Siemens Avanto) for scar delineation using either the standard clinical late gadolinium enhancement (LGE) sequences (n=5) or a novel MR pulse sequence that used an inversion preparation pulse with a wide inversion bandwidth of 2.4kHz (n=5). Results: Standard LGE MR sequences produced a large central signal void with surrounding hyperintensity due to voxel dephasing. The new wide inversion bandwidth sequence reduced the artifact in the right ventricle from 21±7% to 1.2±1.3% (p<.001). Similarly, the new MRI sequence reduced the artifact in the LV from 44±9% to 4.5±5.7% (p<.001). LV artifact location changed from 100% (inferior), 100% (septal), 100% (lateral) and 100% (anterior) to 0%, 0%, 0% and 60%, respectively. Similarly, the LV artifact present was present in the basal, mid and apical segment in 100%, 100%, and 100% in the old sequence but was reduced to 0%, 60%, and 20% in the new sequence (Fig.1). While the artifact of the standard sequence prevented the reliable predictions of the voltage-defined scar during VT ablation, no significant low voltage area outside the imaged LGE areas were found in the patients imaged with the new MRI sequence. Conclusions: Widening the inversion bandwidth achieves a dramatic reduction in ICD metal artifact during LGE CMR imaging and allows a near completely evaluation of the whole myocardium. This allowed the reliable prediction of low voltage areas during VT ablation despite presence of ICD.

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Abstract 17371: In-Hospital Outcomes of Ablation for Ventricular Tachycardia in Heart Failure With Reduced Ejection Fraction

Circulation ◽

10.1161/circ.142.suppl_3.17371 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Raj Patel ◽

Dipesh Ludhwani ◽

Harsh P Patel ◽

Samarthkumar J Thakkar ◽

Love shah ◽

...

Keyword(s):

Myocardial Infarction ◽

Heart Failure ◽

Ventricular Tachycardia ◽

Catheter Ablation ◽

Ejection Fraction ◽

Reference Group ◽

Coronary Bypass ◽

Reference Population ◽

Reduced Ejection Fraction ◽

Vt Ablation

Introduction: Ventricular tachycardia (VT) is a significant cause of morbidity and mortality in patients with heart failure with reduced ejection fraction (HFrEF). Hypothesis: Data on efficacy, safety, and outcomes of catheter ablation for VT in HFrEF have not been studied well. Methods: The 2002-2014 Nationwide Inpatient Sample (NIS) was used to identify all hospitalizations with a principle diagnosis of VT (International Classification of Diseases, Ninth Edition, Clinical Modification [ICD-9-CM] code 427.1) and a secondary diagnosis of HFrEF. Patients who underwent catheter ablation were identified using ICD-9-CM procedure code 37.34. Results: Of 228,557 patients with HFrEF & VT, 5845 (2.56%) underwent catheter ablation. The prevalence of Diabetes Mellitus (DM) and Chronic Kidney disease (CKD) was higher in the reference population contrary to a higher prevalence of prior myocardial infarction (MI), coronary bypass and AICD in those undergoing CA. The frequency of complications in the ablation group was 19.47%, the most common being post-operative hemorrhage (8.3%). This was followed by myocardial infarction (5.34%), pericardial complications (3.38%), and neurological complications (2.14%) (Figure 1.). The odds of in-hospital mortality were lower in the CA group compared to the reference group (5.08% vs 9.42%, p<0.05). Conclusions: Compared to medical therapy, VT ablation in HFrEF is associated with lower mortality though with significant complication rate. This suggests a need for future studies identifying the safety measures in VT ablations and instituting appropriate interventions to improve overall VT ablation outcomes.

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Abstract 4092: Initial Experience with Subxiphoid Percutaneous Epicardial Ventricular Tachycardia Ablation in Patients with Prior Cardiac Surgery

Circulation ◽

10.1161/circ.118.suppl_18.s_827 ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Srijoy Mahapatra ◽

George M McDaniel ◽

Pamela K Mason ◽

Gorav Ailawadi

Keyword(s):

Cardiac Surgery ◽

Success Rate ◽

Nyha Class ◽

Surgical Patients ◽

Surgical Patient ◽

Success Rates ◽

Ventricular Tachycardia Ablation ◽

Prior Surgery ◽

Vt Ablation ◽

Surgical Group

Introduction: Epicardial ablation via subxiphoid percutaenous access improves VT ablation success rate and is growing in popularity. However, it is unclear if this technique is feasible in patients with prior cardiac surgery because of pericardial adhesions. We describe results in our initial 12 patients with previous cardiac surgery. Methods: A total of 27 patients (11 women) underwent an epicardial VT ablation after failed antiarrhythmic drug therapy and at least one endocardial ablation. Twelve patients had undergone previous cardiac surgery (7 CABG, 3 valve only, 2 combined). The pericardium was accessed using a Tuohy needle. Then a guidewire and an irrigated tip catheter were used to free up adhesions. VT was mapped and ablated. We compared the results in patients with and without prior surgery. Results: There was no difference in the age (62±11 vs 58±13 years, p=ns), percent women (41 vs 40%, p=ns), EF (30±9 vs 27±11, p=ns), NYHA class (2.4±1.0 vs 2.1±0.9, p=ns) or use of beta-blockers (100 vs 93%, p=ns) or ACE inhibtors (100 vs 93%, p=ns) among patients with and without prior cardiac surgery. However, patients with prior surgery were more likely to have CAD (100 vs 66% p=0.02) and be on ASA (100 vs 73%, p=0.04.) The mean procedure (298±90 vs 178±45 min, p=0.01) and fluoroscopy time (106±24 vs 45±11 min, p=0.01) was longer in patients with prior surgery versus without surgery. The entire epicardium was mapped in 15/15 (100%) of the nonsurgical patients but only in 7/11 (64%) of the surgical patients due to adhesions (p=0.02.) The acute success rate, defined as elimination of all clinical VTs, was lower in the surgical group (75 vs 100%, p=0.02). Elimination of all VTs was achieved less often in post-surgical patient than non-surgical patients (58 vs 80%, p=0.04.) There were two occurrences of RV perforation in each group both treated with conservative therapy. There were no other complications. After 7±2 months, 66% of surgical patients and 80% of non-surgical patients were VT free (p=0.04) as monitored by ICD or 1, 3, and 6 month monitor. One patient in non-surgical group died of heart failure. Conclusion: Prior cardiac surgery does not preclude epicardial VT ablation but is associated with longer procedure times and lower success rates.

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Abstract 14985: Presence of Repolarization Gradients Reverses Post-infarct Ventricular Tachycardia Exit and Entrance Sites in Personalized Digital Hearts

Circulation ◽

10.1161/circ.142.suppl_3.14985 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

Eric Sung ◽

Adityo Prakosa ◽

Natalia Trayanova

Keyword(s):

Border Zone ◽

Non Invasive ◽

Cycle Lengths ◽

Rapid Pacing ◽

Vt Ablation ◽

Right Ventricular Apex ◽

The Right ◽

Ventricular Tachycardias ◽

Infarct Border Zone ◽

Infarct Border

Introduction: Post-infarct ventricular tachycardias (VT) arise due to structural remodeling (scarring). Physiological repolarization gradients (apicobasal and transmural) exist in the human heart, but the effects on post-infarct VT dynamics are unknown. Hypothesis: We hypothesized that incorporation of repolarization gradients in personalized digital hearts of post-infarct patients impacts VT exit sites without altering the location of the VTs. Methods: 3D late-gadolinium enhanced CMR images were acquired from 7 post-infarct patients. Personalized image-based computational heart models (digital hearts) representing scar and infarct border zone distributions were constructed. Apicobasal (AB) and transmural (TM) repolarization gradients were incorporated using a validated method (Fig A). VTs were induced at baseline (no repolarization gradient) via rapid pacing in the right ventricular apex, using two pacing cycle lengths, mimicking non-invasive programmed stimulation. Pacing protocols that induced baseline VTs were repeated under AB and TM conditions. Results: Ten VTs were induced in baseline digital hearts. 8 AB VTs and 8 TM VTs were induced; the remaining 2 VTs for both AB and TM digital hearts could not be induced. 5/8 induced AB VTs had VT exit sites matching baseline VT exit sites; the remaining 3/8 AB VTs had reversed VT exit and entrance sites from the corresponding baseline VTs (Fig B, VT 1 & 2). 4/8 induced TM VTs had exit sites that matched those at baseline; the remaining TM VTs had exit and entrance sites reversed from those of baseline VTs (Fig B, VT 1, 2 & 3). All 8 AB VTs and 8 TM VTs had the same location as corresponding baseline VTs. Conclusion: AB and TM repolarization gradients can act to reverse VT entrance and exit sites without changing VT location. Thus, incorporation of physiological repolarization gradients into personalized digital hearts may not impact VT ablation targeting but may affect accurate prediction of VT exit or entrance sites.

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