Activation mapping in sinus rhythm in patients with ventricular tachycardia-relationship to cycle length and site of origin

The optimal method to identify the arrhythmogenic substrate of scar-related ventricular tachycardia (VT) is unknown. Sites of activation slowing during sinus rhythm (SR) often co-localize with the VT circuit. This is a report of two scar related VT substrate mapping using a strategy of voltage-independent approach.

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Information theory to tachycardia therapy: electrogram entropy predicts diastolic microstructure of reentrant ventricular tachycardia

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00581.2018 ◽

2019 ◽

Vol 316 (1) ◽

pp. H134-H144 ◽

Cited By ~ 1

Author(s):

Sachin Nayyar ◽

Eugene Downar ◽

Mohammadali Beheshti ◽

Timothy Liang ◽

Stéphane Massé ◽

...

Keyword(s):

Mathematical Modeling ◽

Ventricular Tachycardia ◽

Sinus Rhythm ◽

Main Channel ◽

Single Individual ◽

Minimum Entropy ◽

Structural Representation ◽

Scar Region ◽

Low Entropy ◽

Activation Mapping

There is no known strategy to differentiate which multicomponent electrograms in sinus rhythm maintain reentrant ventricular tachycardia (VT). Low entropy in the voltage breakdown of a multicomponent electrogram can localize conditions suitable for reentry but has not been validated against the classic VT activation mapping. We examined whether low entropy in a late and diversely activated ventricular scar region characterizes and differentiates the diastolic path of VT and represents protected tissue channels devoid of side branches. Intraoperative bipolar electrogram (BiEGM) activation and entropy maps were obtained during sinus rhythm in 17 patients with ischemic cardiomyopathy and compared with diastolic activation paths of VT (total of 39 VTs). Mathematical modeling of a zigzag main channel with side branches was also used to further validate structural representation of low entropy in the ventricular scar. A median of one region per patient (range: 1–2 regions) was identified in sinus rhythm, in which BiEGMwith the latest mean activation time and adjacent minimum entropy were assembled together in a high-activation dispersion region. These regions accurately recognized diastolic paths of 34 VTs, often to multiple inducible VTs within a single individual arrhythmogenic region. In mathematical modeling, side branching from the main channel had a strong influence on the BiEGMcomposition along the main channel. The BiEGMobtained from a long unbranched channel had the lowest entropy compared with those with multiple side branches. In conclusion, among a population of multicomponent sinus electrograms, those that demonstrate low entropy and are delayed colocalize to critical long-protected channels of VT. This information is pertinent for planning VT ablation in sinus rhythm.NEW & NOTEWORTHY Entropy is a measure to quantify breakdown in information. Electrograms from a protected tissue channel can only possess a few states in their voltage and thus less information. In contrast, current-load interactions from side branches in unprotected channels introduce a number of dissimilar voltage deflections and thus high information. We compare here a mapping approach based on entropy against a rigorous reference standard of activation mapping during VT and entropy was assessed in sinus rhythm.

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Catheter Ablation of Ventricular Tachycardia in LMNA Cardiomyopathy: Out of Sight but not Out of Mind

10.22541/au.162605915.53218041/v1 ◽

2021 ◽

Author(s):

Ahmad Halawa ◽

Paul Zei ◽

Neal Lakdawala ◽

William Sauer ◽

Usha Tedrow ◽

...

Keyword(s):

Ventricular Tachycardia ◽

Catheter Ablation ◽

Success Rate ◽

Ventricular Arrhythmias ◽

Cycle Length ◽

Electrical Storm ◽

Arrhythmogenic Substrate ◽

Ablation Success ◽

Endocardial Mapping ◽

Activation Mapping

Lamin Cardiomyopathy (LC) is associated with refractory ventricular arrhythmias. Catheter ablation success rate is low due to presence of multiple circuits and intramural substrate. We present a LC case presented with electrical storm. During catheter ablation, arrhythmia was easily inducible but activation mapping, including full epicardial and endocardial mapping, failed to demonstrate the full tachycardia cycle length (70% only) suggesting intramural activation. Critical isthmus was not identified even with successful concealed entrainment on both Endo/epicardial surfaces. This case shows that even combined endocardial and epicardial catheter approach can be ineffective in identifying the full arrhythmogenic substrate in LC.

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Faculty Opinions recommendation of Accelerated sinus rhythm prevents catecholaminergic polymorphic ventricular tachycardia in mice and in patients.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717982896.793472089 ◽

2013 ◽

Author(s):

Dirk van Helden ◽

Mohammad Imtiaz

Keyword(s):

Ventricular Tachycardia ◽

Sinus Rhythm ◽

Catecholaminergic Polymorphic Ventricular Tachycardia ◽

Polymorphic Ventricular Tachycardia

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Flecainide How and When: A Practical Guide in Supraventricular Arrhythmias

Journal of Clinical Medicine ◽

10.3390/jcm10071456 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1456

Author(s):

Carlo Lavalle ◽

Michele Magnocavallo ◽

Martina Straito ◽

Luca Santini ◽

Giovanni Battista Forleo ◽

...

Keyword(s):

Atrial Fibrillation ◽

Ventricular Tachycardia ◽

Drug Treatment ◽

Sinus Rhythm ◽

Antiarrhythmic Drug ◽

Safety Profile ◽

Patient Management ◽

Clinical Use ◽

Supraventricular Arrhythmias ◽

Sinus Rhythm Maintenance

Transcatheter ablation was increasingly and successfully used to treat symptomatic drug refractory patients affected by supraventricular arrhythmias. Antiarrhythmic drug treatment still plays a major role in patient management, alone or combined with non-pharmacological therapies. Flecainide is an IC antiarrhythmic drug approved in 1984 from the Food and Drug Administration for the suppression of sustained ventricular tachycardia and later for acute cardioversion of atrial fibrillation and for sinus rhythm maintenance. Currently, flecainide is mostly used for sinus rhythm maintenance in atrial fibrillation (AF) patients without structural cardiomyopathy although recent studies enrolling different patient populations have demonstrated a good effectiveness and safety profile. How should we interpret the results of the CAST after the latest evidence? Is it possible to expand the indications of flecainide, and therefore, its use? This review aims to highlight the main characteristics of flecainide, as well as its optimal clinical use, delineating drug indications and contraindications and appropriate monitoring, based on the most recent evidence.

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