Electrically Unexcitable Scar Mapping Based on Pacing Threshold for Identification of the Reentry Circuit Isthmus

Soejima, Kyoko; Stevenson, William G.; Maisel, William H.; Sapp, John L.; Epstein, Laurence M.

doi:10.1161/01.cir.0000030187.39852.a7

Cited by 320 publications

(247 citation statements)

References 23 publications

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“…CCs are relatively small compared with the scar areas; therefore, this method could permit focus on the diagnostic techniques and ablation to defined areas; in those patients without CCs on the voltage map, a more timedemanding approach could be used. 10 This procedure would allow the ablation of some nontolerated or noninducible VT not approachable by conventional entrainment mapping. Regarding the ablation guided by E-ICD searching, what additional advantage is afforded by channel identification?…”

Section: Advantages Of Ablation Of the Isthmusmentioning

confidence: 99%

“…9 The identification of these CCs before induction of VT may facilitate mapping and/or ablation of tolerated and unmappable VT. Scar mapping based on pacing threshold has been used for the identification of nonconducting tissue that borders viable myocardium during sinus rhythm (SR). 10 To simplify the identification of these CCs during SR, we hypothesized that conducting bundles should have larger voltage amplitude than nonconducting scar. Therefore, voltage maps of the left ventricle might show channels inside the scar, provided that an adequate adjustment of voltage definition of nonconducting scar is used.…”

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confidence: 99%

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Tachycardia-Related Channel in the Scar Tissue in Patients With Sustained Monomorphic Ventricular Tachycardias

et al. 2004

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Background-Endocardial mapping before sustained monomorphic ventricular tachycardia (SMVT) induction may reduce mapping time during tachycardia and facilitate the ablation of unmappable VT. Methods and Results-Left ventricular electroanatomic voltage maps obtained during right ventricular apex pacing in 26 patients with chronic myocardial infarction referred for VT ablation were analyzed to identify conducting channels (CCs) inside the scar tissue. A CC was defined by the presence of a corridor of consecutive electrograms differentiated by higher voltage amplitude than the surrounding area. The effect of different levels of voltage scar definition, from 0.5 to 0.1 mV, was analyzed. Twenty-three channels were identified in 20 patients. The majority of CCs were identified when the voltage scar definition was Յ0.2 mV. Electrograms with Ն2 components were recorded more frequently at the inner than at the entrance of CCs (100% versus 75%, PՅ0.01). The activation time of the latest component was longer at the inner than at the entrance of CCs (200Ϯ40 versus 164Ϯ53 ms, PՅ0.001). Pacing from these CCs gave rise to a long-stimulus QRS interval (110Ϯ49 ms). Radiofrequency lesion applied to CCs suppressed the inducibility in 88% of CC-related tachycardias. During a follow-up of 17Ϯ11 months, 23% of the patients experienced a VT recurrence. Conclusions-CCs represent areas of slow conduction that can be identified in 75% of patients with SMVT. A tiered decreasing-voltage definition of the scar is critical for CC identification.

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Section: Advantages Of Ablation Of the Isthmusmentioning

confidence: 99%

mentioning

confidence: 99%

Tachycardia-Related Channel in the Scar Tissue in Patients With Sustained Monomorphic Ventricular Tachycardias

et al. 2004

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“…7 Offline analysis of the digitally stored electrograms and pace maps was performed on the Bard EP system with the use of on-screen calipers at a sweep speed of 200 mm/s. Pace maps were physically searched and matched for at least 11 of 12-lead matches in the surface ECG QRS morphology.…”

Section: Vt Channel Localizationmentioning

confidence: 99%

“…5 As an alternative, substrate-based ablation strategies emphasize targeting all excitable abnormal electrograms within the scar. 6,7 The splitting in fractionated, late, and very late potentials is considered indicative of underlying surviving myocyte bundles with discontinuous conduction. [8][9][10] However, the information content of a VT supporting channel remains obscure in this scheme of abnormal electrogram classification, and, in fact, many are innocuous bystanders.…”

mentioning

confidence: 99%

Development of Time- and Voltage-Domain Mapping (V-T-Mapping) to Localize Ventricular Tachycardia Channels During Sinus Rhythm

Nayyar

Kuklik

Ganesan

et al. 2016

Circ: Arrhythmia and Electrophysiology

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Background-In ventricular scar, impulse spread is slow because it traverses split and zigzag channels of surviving muscle.We aimed to evaluate scar electrograms to determine their local delay (activation time) and inequality in voltage splitting (entropy), and their relationship to channels. We reasoned that unlike innocuous channels, which are often short with multiple side branches, ventricular tachycardia (VT) supporting channels have very slow impulse spread and possess low entropy because of their longer protected length and relative lack of side-branching. Methods and Results-Patients with ischemic cardiomyopathy and multiple VT were studied. In initial mapping stage (16 patients and 58 VTs), left ventricular endocardial mapping was performed in sinus rhythm. Detailed pace mapping was used to identify VT channels and confirmed, when feasible, by entrainment. Scar electrograms were analyzed in time and voltage domains to determine mean activation time, dispersion in activation time, and entropy. Predictive performances of these properties to detect VT channels were tested. In the application stage (7 patients and 20 VTs), these properties were prospectively tested to guide catheter ablation. A mean number of 763±203 sampling points were taken. From 1770 pace maps, 47 channels corresponded to VTs. A combination of scar electrograms with the latest mean activation time and minimum entropy, in a high activation dispersion region, accurately recognized regions containing VT channels (κ=0.89, sensitivity=86%, specificity=100%, positive predictive value=93%, and negative predictive value=100%). Finally, focused ablation within 5-mm rim of the prospective channel regions eliminated 18 of 20 inducible VTs. Conclusions-Activation time and entropy mapping in the scar accurately identify VT channels during sinus rhythm. The method integrates principles of reentry formation to recognize VT channels without pace mapping or mapping during VT. (Circ Arrhythm Electrophysiol. 2016;9:e004050.

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“…The target VT is rendered acutely non-inducible in 70-90 % of patients. 7,49 The success rate of abolishing all inducible VTs is significantly lower (approximately 50 %). 8,50 A recent meta-analysis of four randomised and one observational study of VT ablation for structural heart disease demonstrated a significant 38 % reduction in VT recurrence compared with medical therapy.…”

Section: Scar-related Ventricular Tachycardiamentioning

confidence: 99%

Catheter Ablation for Ventricular Arrhythmias

Nof

Stevenson

John

2013

Arrhythmia &Amp; Electrophysiology Review

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Sustained ventricular tachycardia (VT) and ventricular fibrillation (VF)are typically a manifestation of significant structural heart disease and often associated with a high risk of sudden cardiac death. Implantable cardioverter defibrillators (ICDs) remain the mainstay of therapy for prevention of sudden cardiac death associated with these arrhythmias. 1 However, ICDs treat the arrhythmia after it occurs and does not prevent the arrhythmia. Recurrent ventricular arrhythmias can lead to multiple ICD shocks that are painful, decrease quality of life and cause post-traumatic stress disorder. Spontaneous VT and ICD shocks are also associated with an increased risk of death and progressive heart failure.2 Antiarrhythmic drugs, notably amiodarone, reduce arrhythmias for some patients, but have limited efficacy for long-term management, particularly for scar-related re-entrant arrhythmias. 3In addition, antiarrhythmic drugs have the potential for significant adverse effects that includes negative inotropy, pro-arrhythmia and non-cardiac organ toxicities that limit their long-term use.3,4 Catheter ablation offers an alternative therapy for preventing arrhythmias, and can be life-saving when frequent episodes (VT storm) threaten survival.VT or repetitive premature ventricular contractions (PVCs) may also occur in the absence of structural heart disease.5 These arrhythmias are often termed 'idiopathic' and generally carry a benign prognosis, but symptoms warrant therapy in some patients. In addition, frequent ventricular arrhythmia can lead to ventricular dysfunction. 6 The cause of depressed ventricular function is often unclear at the initial presentation and the diagnosis of arrhythmia induced ventricular dysfunction may become apparent only after effective suppression of PVCs or VT. Mapping and Ablation Technologies and Procedural ConsiderationsRadiofrequency (RF) current remains the most commonly used energy source. Lesion size is limited by coagulum formation on the electrode when electrode temperature exceeds 70 degrees Celsius. AbstractCatheter ablation has emerged as an important and effective treatment option for many recurrent ventricular arrhythmias. The approach to ablation and the risks and outcomes are largely determined by the nature of the severity and type of underlying heart disease. In patients with structural heart disease, catheter ablation can effectively reduce ventricular tachycardia (VT) episodes and implantable cardioverter defibrillator (ICD) shocks. For VT and symptomatic premature ventricular beats that occur in the absence of structural heart disease, catheter ablation is often effective as the sole therapy. Advances in catheter technology, imaging and mapping techniques have improved success rates for ablation. This review discusses current approaches to mapping and ablation for ventricular arrhythmias.

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Electrically Unexcitable Scar Mapping Based on Pacing Threshold for Identification of the Reentry Circuit Isthmus

Cited by 320 publications

References 23 publications

Tachycardia-Related Channel in the Scar Tissue in Patients With Sustained Monomorphic Ventricular Tachycardias

Tachycardia-Related Channel in the Scar Tissue in Patients With Sustained Monomorphic Ventricular Tachycardias

Development of Time- and Voltage-Domain Mapping (V-T-Mapping) to Localize Ventricular Tachycardia Channels During Sinus Rhythm

Catheter Ablation for Ventricular Arrhythmias

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