Characteristics of electrograms recorded at reentry circuit sites and bystanders during ventricular tachycardia after myocardial infarction

Kocovic, Dusan Z.; Harada, Tomoo; Friedman, Peter L.; Stevenson, William G.

doi:10.1016/s0735-1097(99)00205-3

Cited by 63 publications

(41 citation statements)

References 15 publications

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“…A single cutoff voltage amplitude may not be feasible in all cases, because voltage of the electrograms at sites at which radiofrequency (RF) ablation was effective had a wide range. [13][14][15] Therefore, analysis of different voltage levels of scar definition may be required for identification of CCs in each patient.…”

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confidence: 99%

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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confidence: 99%

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

et al. 2004

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“…[7][8][9][10][11] Ablation was most effective at sites identified as likely isthmuses on the basis of entrainment and the presence of an isolated potential, as was previously reported. 5 In the present study, the termination rate at isthmus sites was significantly higher in the cooled RF group, suggesting that these reentry circuit isthmuses often exceed the width and depth of a standard RF lesion. The ideal comparison of cooled and standard RF ablation would be a prospective, randomized study.…”

Section: Discussionmentioning

confidence: 40%

“…Termination of VT during RF application was used as the end point for assessing effect, as described previously. [3][4][5] The efficacy of termination was compared for identical types of sites, as identified by entrainment and the presence of isolated potentials. The duration of RF application at sites without termination was analyzed and found to be similar for the cooled and standard RF applications.…”

Section: Discussionmentioning

confidence: 99%

“…Bystander sites are outside the circuit. 3 Sites were further grouped into those with and without an isolated potential present during VT. 5,6 At the end of the procedure, programmed stimulation was used to determine the early results of ablation. Stimulation included burst pacing and 1 to 3 extrastimuli after drive trains of 2 different cycle lengths from 2 different right ventricular sites.…”

Section: Methodsmentioning

confidence: 99%

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Saline-Cooled Versus Standard Radiofrequency Catheter Ablation for Infarct-Related Ventricular Tachycardias

et al. 2001

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Background-Saline cooling of the electrode during radiofrequency (RF) ablation increases lesion size in animal models.If cooled RF also increases lesion size in human infarcts, it should facilitate the termination of ventricular tachycardia (VT). Methods and Results-In 66 patients with VT due to prior infarction, 366 ablation sites, which were classified by entrainment and isolated potentials followed by ablation during VT with either standard RF energy (247 sites

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“…[11][12][13] Conversely, only 50% of central, proximal, or exit sites of macroreentry circuits have abnormal electrograms. 14 On the basis of this, and the fact that substrate ablation can be time-consuming in large regions of scar, 6,15 there has been considerable interest into the problem of electric resolution within the scar 16,17 and a more targeted substrate ablation approach.…”

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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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Characteristics of electrograms recorded at reentry circuit sites and bystanders during ventricular tachycardia after myocardial infarction

Abstract: Isolated potentials are a useful guide to sites in the central-proximal region of the reentry circuit, but often fail to identify exit sites where ablation is successful. Entrainment and analysis of electrograms provide complementary information during mapping of VT.

Cited by 63 publications

References 15 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

Saline-Cooled Versus Standard Radiofrequency Catheter Ablation for Infarct-Related Ventricular Tachycardias

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

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