Substrate Mapping and Ablation for Ventricular Tachycardia: The LAVA approach
Frederic Sacher, MD, PhD; Han S. Lim, MBBS; Nicolas Derval, MD; Arnaud Denis, MD; Benjamin Berte, MD; Seigo Yamashita, MD; Meleze Hocini, MD; Michel Haissaguerre, MD; Pierre Jaïs, MD. From: Hôpital Cardiologique du Haut-Lévêque, LIRYC Institute, Bordeaux University, INSERM 1045, France.
Correspondence: Frederic Sacher, MD, PhD Hôpital Cardiologique du Haut-Lévêque, 33604 Bordeaux-Pessac, France. Tel: +33 5 57 65 64 71; Fax: +33 5 57 65 65 09 E-mail: [email protected]
The work described in this review was supported by a Fondation Leducq Grant (Grant number: 09 CVD 03) and grants from the Agence Nationale de la Recherche (IHU LIRYC ANR-10-IAHU-04 and Equipex MUSIC ANR-11-EQPX-0030). F. Sacher reports honoraria relevant to this topic from Biosense Webster and St. Jude Medical. M. Hocini & M. Haissaguerre report research support from Biosense Webster, St. Jude Medical, & CardoInsight; they are stakeholders in CardioInsight. P. Jais reports travel & lecture fees from Biosense Webster & St. Jude Medical. Other authors: No disclosures. This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/jce.12565. This article is protected by copyright. All rights reserved.
1
Abstract Catheter ablation of ventricular tachycardia (VT) is proven effective therapy particularly in patients with frequent defibrillator shocks. However, the optimal endpoint for VT ablation has been debated and additional endpoints have been proposed. At the same time, ablation strategies aiming at homogenizing the substrate of scar related VT have been reported. Our method to homogenize the substrate consists of local abnormal ventricular activity (LAVA) elimination. LAVA are high frequency sharp signals that represent nearfield signals of slowly conducting tissue and hence potential VT isthmuses. Pacing maneuvers are sometimes required to differentiate them from far-field signals. Delayed enhancement on cardiac MRI and/or wall thinning on Multi-Detector Computed Tomography are also extremely helpful to identify the areas of interest during ablation A strategy aiming at careful LAVA mapping, ablation and elimination is feasible and can be achieved in about 70% of patients with scar related VT. Complete LAVA elimination is associated with a better outcome when compared to LAVA persistence even when VT is rendered non-inducible. This is a simple approach, with a clear endpoint and the ability to ablate in sinus rhythm. This strategy significantly benefits from high definition imaging, mapping, and epicardial access.
Keywords ventricular tachycardia, catheter ablation, imaging,
Catheter ablation of ventricular tachycardia (VT) is proven effective therapy particularly in patients with frequent defibrillator shocks 1. Various substrate modification techniques have been described for unmappable or hemodynamically intolerable VT2, 32-134-6, 6-13. Late potential ablation has been described as a target for VT ablation 8, 11. Noninducibility, despite significant limitations, remained the endpoint in these studies. However, recently the optimal endpoint for VT ablation has been frequently debated 1. Interestingly, Nogami et al.14 targeted late potentials (LP) in patients with arrhythmogenic right ventricular dysplasia. They proposed change in LP as an endpoint for ablation and postulated that qualitative analyses of serial signal-averaged ECGs could be useful during long-term follow-up. We recently showed that elimination of local abnormal ventricular activities (LAVA) during sinus rhythm or ventricular pacing was an effective endpoint for substrate-based VT ablation1, 15. This review will describe the identification of LAVA, their relation to the scar based on imaging studies and how to use them as an endpoint for VT ablation. A) How to identify LAVA 1) Definition of LAVA.
This article is protected by copyright. All rights reserved.
2
Local Abnormal Ventricular Activity (LAVA) is a global term that incorporates all abnormal ventricular signals that represent nearfield signals of slowly conducting tissue and hence potential VT isthmuses. Most LAVA reside in scar or border zone tissue and will appear as late potentials (LP). However, this is not always the case depending on its location, such as septal vs lateral and endocardial vs epicardial16. The electrophysiological definition and properties of LAVA include the following: 1) sharp ventricular potential of high frequency (high dV/dP) ± low amplitude signal, but this is not always the case (Figure 1) 2) distinct from the far-field ventricular electrogram (sinus rhythm or pacing) 3) occurring anytime during (rarely) or after the V EGM in sinus rhythm or before the V EGM during VT (Figure 2) 4) sometimes displaying fractionation (Figure 1), double or multiple components separated by very low amplitude signals, or an isoelectric interval. 5) poorly coupled to the rest of the myocardium as demonstrated by the maneuvers detailed below 2) Settings To be able to identify these signals it is important to use high amplification with a low level of noise (Figure 3). LAVA voltage may be extremely different from almost 1.5mV in the border zone and in the absence of transmural scar to less than 0.05mV in dense scar. In the absence of clear LAVA in area of dense scar (
Frederic Sacher, MD, PhD; Han S. Lim, MBBS; Nicolas Derval, MD; Arnaud Denis, MD; Benjamin Berte, MD; Seigo Yamashita, MD; Meleze Hocini, MD; Michel Haissaguerre, MD; Pierre Jaïs, MD. From: Hôpital Cardiologique du Haut-Lévêque, LIRYC Institute, Bordeaux University, INSERM 1045, France.
Correspondence: Frederic Sacher, MD, PhD Hôpital Cardiologique du Haut-Lévêque, 33604 Bordeaux-Pessac, France. Tel: +33 5 57 65 64 71; Fax: +33 5 57 65 65 09 E-mail: [email protected]
The work described in this review was supported by a Fondation Leducq Grant (Grant number: 09 CVD 03) and grants from the Agence Nationale de la Recherche (IHU LIRYC ANR-10-IAHU-04 and Equipex MUSIC ANR-11-EQPX-0030). F. Sacher reports honoraria relevant to this topic from Biosense Webster and St. Jude Medical. M. Hocini & M. Haissaguerre report research support from Biosense Webster, St. Jude Medical, & CardoInsight; they are stakeholders in CardioInsight. P. Jais reports travel & lecture fees from Biosense Webster & St. Jude Medical. Other authors: No disclosures. This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/jce.12565. This article is protected by copyright. All rights reserved.
1
Abstract Catheter ablation of ventricular tachycardia (VT) is proven effective therapy particularly in patients with frequent defibrillator shocks. However, the optimal endpoint for VT ablation has been debated and additional endpoints have been proposed. At the same time, ablation strategies aiming at homogenizing the substrate of scar related VT have been reported. Our method to homogenize the substrate consists of local abnormal ventricular activity (LAVA) elimination. LAVA are high frequency sharp signals that represent nearfield signals of slowly conducting tissue and hence potential VT isthmuses. Pacing maneuvers are sometimes required to differentiate them from far-field signals. Delayed enhancement on cardiac MRI and/or wall thinning on Multi-Detector Computed Tomography are also extremely helpful to identify the areas of interest during ablation A strategy aiming at careful LAVA mapping, ablation and elimination is feasible and can be achieved in about 70% of patients with scar related VT. Complete LAVA elimination is associated with a better outcome when compared to LAVA persistence even when VT is rendered non-inducible. This is a simple approach, with a clear endpoint and the ability to ablate in sinus rhythm. This strategy significantly benefits from high definition imaging, mapping, and epicardial access.
Keywords ventricular tachycardia, catheter ablation, imaging,
Catheter ablation of ventricular tachycardia (VT) is proven effective therapy particularly in patients with frequent defibrillator shocks 1. Various substrate modification techniques have been described for unmappable or hemodynamically intolerable VT2, 32-134-6, 6-13. Late potential ablation has been described as a target for VT ablation 8, 11. Noninducibility, despite significant limitations, remained the endpoint in these studies. However, recently the optimal endpoint for VT ablation has been frequently debated 1. Interestingly, Nogami et al.14 targeted late potentials (LP) in patients with arrhythmogenic right ventricular dysplasia. They proposed change in LP as an endpoint for ablation and postulated that qualitative analyses of serial signal-averaged ECGs could be useful during long-term follow-up. We recently showed that elimination of local abnormal ventricular activities (LAVA) during sinus rhythm or ventricular pacing was an effective endpoint for substrate-based VT ablation1, 15. This review will describe the identification of LAVA, their relation to the scar based on imaging studies and how to use them as an endpoint for VT ablation. A) How to identify LAVA 1) Definition of LAVA.
This article is protected by copyright. All rights reserved.
2
Local Abnormal Ventricular Activity (LAVA) is a global term that incorporates all abnormal ventricular signals that represent nearfield signals of slowly conducting tissue and hence potential VT isthmuses. Most LAVA reside in scar or border zone tissue and will appear as late potentials (LP). However, this is not always the case depending on its location, such as septal vs lateral and endocardial vs epicardial16. The electrophysiological definition and properties of LAVA include the following: 1) sharp ventricular potential of high frequency (high dV/dP) ± low amplitude signal, but this is not always the case (Figure 1) 2) distinct from the far-field ventricular electrogram (sinus rhythm or pacing) 3) occurring anytime during (rarely) or after the V EGM in sinus rhythm or before the V EGM during VT (Figure 2) 4) sometimes displaying fractionation (Figure 1), double or multiple components separated by very low amplitude signals, or an isoelectric interval. 5) poorly coupled to the rest of the myocardium as demonstrated by the maneuvers detailed below 2) Settings To be able to identify these signals it is important to use high amplification with a low level of noise (Figure 3). LAVA voltage may be extremely different from almost 1.5mV in the border zone and in the absence of transmural scar to less than 0.05mV in dense scar. In the absence of clear LAVA in area of dense scar (
