scholarly journals Arrhythmia Mechanisms Revealed by Ripple Mapping

2018 ◽  
Vol 7 (4) ◽  
pp. 1 ◽  
Author(s):  
George Katritsis ◽  
Vishal Luther ◽  
Prapa Kanagaratnam ◽  
Nick WF Linton ◽  
◽  
...  
Keyword(s):  
Expert Opinion ◽  
Ventricular Tachyarrhythmias ◽  
Local Activation ◽  
Intracardiac Electrogram ◽  
Arrhythmia Mechanisms ◽  
Electrophysiological Procedures ◽  
Novel Method ◽  
Mapping Techniques ◽  
Activation Times ◽  
Prior Assignment

Ripple mapping is a novel method of 3D intracardiac electrogram visualisation that allows activation of the myocardium to be tracked visually without prior assignment of local activation times and without interpolation into unmapped regions. It assists in the identification of tachycardia mechanism and optimal ablation site, without the need for an experienced computer-operating assistant. This expert opinion presents evidence demonstrating the benefit of Ripple Mapping, compared with traditional electroanatomic mapping techniques, for the diagnosis and management of atrial and ventricular tachyarrhythmias during electrophysiological procedures.

scholarly journals Effects of local activation times on the tension development of human cardiomyocytes in a computational model

2018 ◽  
Vol 4 (1) ◽  
pp. 247-250
Author(s):  
Armin Müller ◽  
Ekaterina Kovacheva ◽  
Steffen Schuler ◽  
Olaf Dössel ◽  
Lukas Baron
Keyword(s):  
Human Heart ◽  
Maximum Pressure ◽  
Simulation Framework ◽  
Activation Time ◽  
Tension Development ◽  
Human Cardiomyocytes ◽  
Local Activation ◽  
Activation Times ◽  
The Right ◽  
Simulation Time

AbstractThe human heart is an organ of high complexity and hence, very challenging to simulate. To calculate the force developed by the human heart and therefore the tension of the muscle fibers, accurate models are necessary. The force generated by the cardiac muscle has physiologically imposed limits and depends on various characteristics such as the length, strain and the contraction velocity of the cardiomyocytes. Another characteristic is the activation time of each cardiomyocyte, which is a wave and not a static value for all cardiomyocytes. To simulate a physiologically correct excitation, the functionality of the cardiac simulation framework CardioMechanics was extended to incorporate inhomogeneous activation times. The functionality was then used to evaluate the effects of local activation times with two different tension models. The active stress generated by the cardiomyocytes was calculated by (i) an explicit function and (ii) an ode-based model. The results of the simulations showed that the maximum pressure in the left ventricle dropped by 2.3% for the DoubleHill model and by 5.3% for the Lumens model. In the right ventricle the simulations showed similar results. The maximum pressure in both the left and the right atrium increased using both models. Given that the simulation of the inhomogeneously activated cardiomyocytes increases the simulation time when used with the more precise Lumens model, the small drop in maximum pressure seems to be negligible in favor of a simpler simulation model

scholarly journals Probabilistic Interpolation of Uncertain Local Activation Times on Human Atrial Manifolds

2020 ◽  
Vol 67 (1) ◽  
pp. 99-109 ◽  
Author(s):  
Sam Coveney ◽  
Richard H. Clayton ◽  
Cesare Corrado ◽  
Caroline H. Roney ◽  
Richard D. Wilkinson ◽  
...  
Keyword(s):  
Local Activation ◽  
Activation Times

Ventricular conduction stability test: a method to identify and quantify changes in whole heart activation patterns during physiological stress

EP Europace ◽  
2019 ◽  
Vol 21 (9) ◽  
pp. 1422-1431
Author(s):  
Matthew J Shun-Shin ◽  
Kevin M W Leong ◽  
Fu Siong Ng ◽  
Nicholas W F Linton ◽  
Zachary I Whinnett ◽  
...  
Keyword(s):  
Sudden Cardiac Death ◽  
Cardiac Death ◽  
Physiological Stress ◽  
Exercise Treadmill ◽  
Abnormal Rate ◽  
Length Changes ◽  
Mapping Techniques ◽  
Whole Heart ◽  
Activation Times ◽  
Ventricular Conduction

Abstract Aims Abnormal rate adaptation of the action potential is proarrhythmic but is difficult to measure with current electro-anatomical mapping techniques. We developed a method to rapidly quantify spatial discordance in whole heart activation in response to rate cycle length changes. We test the hypothesis that patients with underlying channelopathies or history of aborted sudden cardiac death (SCD) have a reduced capacity to maintain uniform activation following exercise. Methods and results Electrocardiographical imaging (ECGI) reconstructs >1200 electrograms (EGMs) over the ventricles from a single beat, providing epicardial whole heart activation maps. Thirty-one individuals [11 SCD survivors; 10 Brugada syndrome (BrS) without SCD; and 10 controls] with structurally normal hearts underwent ECGI vest recordings following exercise treadmill. For each patient, we calculated the relative change in EGM local activation times (LATs) between a baseline and post-exertion phase using custom written software. A ventricular conduction stability (V-CoS) score calculated to indicate the percentage of ventricle that showed no significant change in relative LAT (<10 ms). A lower score reflected greater conduction heterogeneity. Mean variability (standard deviation) of V-CoS score over 10 consecutive beats was small (0.9 ± 0.5%), with good inter-operator reproducibility of V-CoS scores. Sudden cardiac death survivors, compared to BrS and controls, had the lowest V-CoS scores post-exertion (P = 0.011) but were no different at baseline (P = 0.50). Conclusion We present a method to rapidly quantify changes in global activation which provides a measure of conduction heterogeneity and proof of concept by demonstrating SCD survivors have a reduced capacity to maintain uniform activation following exercise.

A novel method to enhance phenotype, epicardial functional substrates, and ventricular tachyarrhythmias in Brugada syndrome

Heart Rhythm ◽  
2017 ◽  
Vol 14 (4) ◽  
pp. 508-517 ◽  
Author(s):  
Fa-Po Chung ◽  
Sunu Budhi Raharjo ◽  
Yenn-Jiang Lin ◽  
Shih-Lin Chang ◽  
Li-Wei Lo ◽  
...  
Keyword(s):  
Brugada Syndrome ◽  
Ventricular Tachyarrhythmias ◽  
Novel Method

Abstract 18650: Activation Mapping of Ventricular Ectopy: Characterization of a Threshold Value Predicting Successful Catheter Ablation

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Will Camnitz ◽  
Kenneth Bilchick ◽  
John Dimarco ◽  
Kevin Driver ◽  
John Ferguson ◽  
...  
Keyword(s):  
Catheter Ablation ◽  
Threshold Value ◽  
Accurate Method ◽  
Ventricular Ectopy ◽  
Activation Time ◽  
Local Activation ◽  
Successful Ablation ◽  
Activation Times ◽  
Local Activation Time ◽  
Activation Mapping

Background: Catheter ablation of ventricular ectopy is performed with increasing frequency. Activation mapping to determine the site with the earliest presystolic electrogram (EGM) is the most accurate method to locate the optimal ablation site. Despite this, activation mapping of ventricular ectopy has not been systematically reviewed in a large series, and the optimal activation time predicting successful ablation has not previously been determined. The goal of this study is to determine the local presystolic activation time most predictive of successful ablation. Methods and Results: We retrospectively reviewed 100 consecutive successful endocardial PVC ablations and analyzed the local activation time at each successful and unsuccessful ablation site. A total of 561 ablation lesions were reviewed. Activation time was calculated as the difference between the peak of the local bipolar EGM and the onset of the reference surface QRS complex. Acute success was defined as complete elimination of the target PVC during the procedure with no recurrence at 30 days by ECG and follow-up Holter. A local activation time 27 msec presystolic best predicted success with a sensitivity of 88%, specificity 85%, and an area under the ROC curve of 0.936 (95% CI 0.91 - 0.95; figure 1). The 27 msec presystolic activation time remained most predictive of success after sub-stratifying activation times by location (RVOT v LVOT, outflow v intracavitary). The odds ratio for success with each 1 msec increase in activation time (becomes more negative by 1 msec) is 1.24 (95% CI 1.19 - 1.29). Conclusion: In our experience, a local presystolic activation time of 27 msec is the threshold value most predictive of successful PVC ablation. Our review is the first to systematically characterize an activation time predicting success with PVC ablation in a large cohort. Figure 1

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