Characteristics of Sinus Rhythm Electrograms at Sites of Ablation of Ventricular Tachycardia Relative to All Other Sites: A Noncontact Mapping Study of the Entire Left Ventricle

Rj, Schilling; Dw, Davies; Peters, Nils

doi:10.1111/j.1540-8167.1998.tb00133.x

Cited by 55 publications

(44 citation statements)

References 22 publications

(1 reference statement)

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“…2,4 In brief, the MEA consists of 64 wires, each with a laser-etched electrode, mounted on a 7.5-mL balloon. The electrical signals from the MEA are recorded by an amplifier with a sampling rate of 1.2 kHz and a filtering bandwidth of 0.1 to 300 Hz.…”

Section: Methods Equipmentmentioning

confidence: 99%

“…The virtual electrograms computed by this noncontact mapping system have been shown to have a good morphological correlation with contact electrograms from the same location. 1,2 Identifying ventricular scar is important because ventricular tachycardia (VT) reentrant circuits are often located in the border zone surrounding scarred myocardium. 6 -8 Accurate scar localization would also allow lines of block to be made between the scar and anatomic limits such as valve orifices.…”

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confidence: 99%

“…A noncontact mapping system (EnSite 3000) is currently in use [1][2][3][4][5] that calculates virtual electrograms simultaneously at 3360 locations within the chamber of interest, thus enabling arrhythmias to be mapped rapidly. The virtual electrograms computed by this noncontact mapping system have been shown to have a good morphological correlation with contact electrograms from the same location.…”

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confidence: 99%

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Value of Noncontact Mapping for Identifying Left Ventricular Scar in an Ovine Model

et al. 2004

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Background-We assessed the hypothesis that "virtual electrograms" from a noncontact mapping system (EnSite 3000) could be used to localize myocardial scar. Methods and Results-Myocardial infarctions were induced in sheep by inflating an angioplasty balloon in the left anterior descending coronary artery for 3 hours. Scar mapping was performed on 8 sheep without inducible ventricular tachycardia by use of the noncontact mapping system and a 256-channel contact mapping system. Transmural mapping needles were inserted into myocardial regions that were (1) scarred, (2) peripheral to the scar, and (3) distant from the scar. Unipolar electrograms were exported from both systems and analyzed on a personal computer workstation. The percentage of myocardial scarring at each needle site was assessed histologically. Pearson's correlation was used to assess the degree of association between various electrogram characteristics and the presence of myocardial scarring. The only noncontact electrogram characteristic that showed any association with the presence of myocardial scarring was the negative slope duration (contact, rϭ0.62, PϽ0.001; noncontact, rϭ0.23, Pϭ0.004). The other electrogram characteristics studied were electrogram maximal deflection (contact, rϭ0.38, PϽ0.001; noncontact, rϭ0.03, Pϭ0.75) and minimal slope (contact, rϭ0.42, PϽ0.001; noncontact, rϭ0.05, Pϭ0.54

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Section: Methods Equipmentmentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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Value of Noncontact Mapping for Identifying Left Ventricular Scar in an Ovine Model

et al. 2004

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“…The time of latest depolarization during sinus rhythm has been partially correlated to the location of the reentry isthmus; however, the relationship is inexact. 2,3 At the border zone, both normal and abnormal (low-amplitude, fractionated, or wide-deflection) electrograms are present [2][3][4][5] ; these abnormal electrograms, however, can be present both within and away from the reentry circuit location and are therefore not a specific predictor of its position in the border zone. Therefore, methods for detection and measurement of abnormal sinus rhythm activation characteristics are not currently sufficient for targeting reentry circuits for catheter ablation, although the presence of abnormality suggests the proximity of an arrhythmogenic substrate.…”

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confidence: 99%

Relationship Between Sinus Rhythm Activation and the Reentrant Ventricular Tachycardia Isthmus

2001

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Background-In canine hearts with inducible reentry, the isthmus tends to form along an axis from the area of last to first activity during sinus rhythm. It was hypothesized that this phenomenon could be quantified to predict reentry and the isthmus location. Methods and Results-An in situ canine model of reentrant ventricular tachycardia occurring in the epicardial border zone was used in 54 experiments (25 canine hearts in which primarily long monomorphic runs of figure-8 reentry were inducible, 11 with short monomorphic or polymorphic runs, and 18 lacking inducible reentry). From the sinus rhythm activation map for each experiment, the linear regression coefficient and slope were calculated for the activation times along each of 8 rays extending from the area of last activation. The slope of the regression line for the ray with greatest regression coefficient (called the primary axis) was used to predict whether or not reentry would be inducible (correct prediction in 48 of 54 experiments). For all 36 experiments with reentry, isthmus location and shape were then estimated on the basis of site-to-site differences in sinus rhythm electrogram duration. For long and short runs of reentry, estimated isthmus location and shape partially overlapped the actual isthmus (mean overlap of 71.3% and 43.6%, respectively).On average for all reentry experiments, a linear ablation lesion positioned across the estimated isthmus would have spanned 78.2% of the actual isthmus width. Conclusions-Parameters

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“…[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. [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 Sinus Rhythm Electrograms at Sites of Ablation of Ventricular Tachycardia Relative to All Other Sites: A Noncontact Mapping Study of the Entire Left Ventricle

Abstract: Although the site of latest onset of endocardial activation during SR proved to be the most sensitive indicator, the characteristics of SR electrograms did not usefully predict successful ablation sites.

Cited by 55 publications

References 22 publications

Value of Noncontact Mapping for Identifying Left Ventricular Scar in an Ovine Model

Value of Noncontact Mapping for Identifying Left Ventricular Scar in an Ovine Model

Relationship Between Sinus Rhythm Activation and the Reentrant Ventricular Tachycardia Isthmus

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

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